Development and use of food packaging from plant leaves in developing countries PDF

See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/362178821 Development and use of food packaging from plant leaves in developing countries Article in Journal für Verbraucherschutz und Lebensmittelsicherheit · July 2022 DOI: 10.1007/s0000...

See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/362178821 Development and use of food packaging from plant leaves in developing countries Article in Journal für Verbraucherschutz und Lebensmittelsicherheit · July 2022 DOI: 10.1007/s00003-022-01390-0 CITATIONS READS 4 745 9 authors, including: Mathias Hounsou D Sylvain Dabadé 10 PUBLICATIONS 29 CITATIONS University of Abomey-Calavi 42 PUBLICATIONS 374 CITATIONS SEE PROFILE SEE PROFILE Barbara Götz Menouwesso Hounhouigan University of Bonn Université d'Agriculture de Kétou 13 PUBLICATIONS 55 CITATIONS 25 PUBLICATIONS 132 CITATIONS SEE PROFILE SEE PROFILE All content following this page was uploaded by Fernande G Honfo on 18 July 2024. The user has requested enhancement of the downloaded file. Journal of Consumer Protection and Food Safety Journal of Consumer Protection and Food Safety https://doi.org/10.1007/s00003-022-01390-0 Journal für Verbraucherschutz und Lebensmittelsicherheit REVIEW Development and use of food packaging from plant leaves in developing countries Mathias Hounsou1 · D. Sylvain Dabadé1 · Barbara Götz2 · Menouwesso Harold Hounhouigan1 · Fernande Gbènato Honfo1 · Antonia Albrecht2 · Lucas Correa Dresch2 · Judith Kreyenschmidt3 · Djidjoho Joseph Hounhouigan1 Received: 19 March 2022 / Revised: 11 June 2022 / Accepted: 6 July 2022 © Bundesamt für Verbraucherschutz und Lebensmittelsicherheit (BVL) 2022 Abstract Plastic materials are the main food packaging material both in developed and developing countries, because of their reli- able ability to protect and transport food at lower costs. Unfortunately, they harm the environment due to their resistance to biodegradation, lack of waste management, and restricted recyclability. Moreover, they may pose adverse health effects to consumers. Therefore, there is a need to develop environmentally friendly food packaging using bio-based or biodegradable materials. For instance, several innovations based on biopolymers are being developed especially in developed countries. On the other side, in many developing countries, there is a long tradition of using plant leaves as food packaging. These leaves have cultural, religious, and environmental significance in the tropics. Unfortunately, they do not always guarantee the integ- rity of the packaged products and there is a need to promote them to take full advantage of their potential. However, there is little information on leaf packaging in literature. Therefore, this review aims to provide an overview on the state-of-the-art of leaf packaging in developing countries, in an attempt to compile the information required for further investigations needed to take full advantage of the environmental importance of leaf packaging. This study highlights mainly various plant species used as leaf packaging, treatments undergone by the leaves before their use, and leaf packaging effects on food quality and safety. It also discusses future perspectives to promote leaf packaging. Keywords Biodegradable packaging · Plant leaves · Traditional food packaging · Green packaging · Food contact material 1 Introduction solutions have become as important as the packed goods. Petrochemical technology gave rise to diversified types of Food packaging is important for reducing post-harvest loss packaging. In 2020, global plastics production was estimated by preserving food quality during handling and transporta- to be 367 million metric tons (Statista 2022). About 40% of tion (Zhou et al. 2010). Technology and market develop- plastics produced worldwide are used for packaging (Groh ment have brought packaging concepts and designs to new et al. 2019). In Nigeria as well as in many other African dimensions and purposes for food labeling and consumers’ countries including Benin, the everyday use of plastic bags preferences (Grebitus et al. 2013). Therefore, packaging and other single-use plastic products for e.g. takeaway food, drinking water plastic sachets, straws, cups and spoons, etc. is widespread (Dumbili and Henderson 2020). The use of * D. Sylvain Dabadé these plastic packagings increases food quality, safety and [email protected]; [email protected] prolongs its shelf-life (Kitz et al. 2022). However, it can also 1 Laboratory of Food Sciences, Faculty of Agronomic cause adverse health effects to consumers (Hermabessiere Sciences, University of Abomey-Calavi, 03 BP 2819, et al. 2017). Indeed, when manufactured plastic is used to Abomey‑Calavi, Benin pack hot-food products, cancerous compounds such as free 2 Institut of Animal Science, University of Bonn, radicals can migrate into the food (Kirchnawy et al. 2014). Katzenburgweg 7–9, 53115 Bonn, Germany These plastics are made of polyethylene components, poly- 3 Department of Fresh Produce Logistics, Hochschule vinyl chloride, polystyrene or bisphenol A and may contain Geisenheim University, van‑Lade Strasse 1, some additives. And the compounds that decompose under 65336 Geisenheim, Germany 13 Vol.:(0123456789)  M. Hounsou et al. the effect of heat release free radicals that may interfere or to reduce the use of fossil based plastics are still difficult to interact with human hormonal activity (Soto et al. 2006). access due to their occurrence mainly in grey literature. This Over time, they can cause cancer, heart diseases and repro- review aims at providing an overview on the state-of-the-art ductive problems (Sharma et al. 2019). Another issue is that of leaf packaging in developing countries and to compile fossil-based plastic packaging is a limited resource which the information required for further investigations needed compromises the availability of raw material for future to promote leaf packaging. generations (Mustafa et al. 2012). Besides, due to lack of recycling technologies in several countries, accumulation of used plastic waste in nature constitutes one of the biggest 2 Material and methods environmental problems of this century (Gallo et al. 2018). Furthermore, fossil based plastic namely microplastic is an The studies included in this review were selected accord- important problem for the environment and animals, since ing to PRISMA protocol (Moher et al. 2009) as shown in in several developing countries have no recycling companies Fig. 1. Various databases were used, namely Web of Sci- (Alpizar et al. 2020). ence, Science Direct, PubMed, and Google Scholar. The In recent years, implementation of recycling technolo- following search terms were used: “leaf packaging” AND gies and biodegradable packaging from natural materials Food, “leaves packaging” AND Food, “leaf wrapping” has been promoted in developed countries (Han et al. 2018). AND Food, “leaves wrapping” AND Food, “leaf plate” In developing countries, plastic packaging has also become AND Food, “leaves plate” AND Food. In addition, other a concern for public authorities. For example, in several sources mainly from grey literature (universities websites African countries including Benin and Rwanda, the use of non-biodegradable packaging has been banned recently (Nielsen et al. 2019). In most of those developing countries, Records identified Additional records before the large utilization of plastic food packaging, people through databases from other sources used materials extracted from surrounding environment for searching (n = 2260) Identification (n = 18) packaging. In fact, many African, Asian and Latin Ameri- can countries have an old tradition of using leaves to wrap food (Lascurain et al. 2017; Mensah et al. 2012; Ng 2015). Since the surrounding vegetation provides large varieties Records after duplicates removed (n = 1326) of leaves which are suitable for food packaging, they have been tested and proven for long usage, and are regarded as non-toxic with no containing, dyes or irritants (Mensah et al. Screening 2012; Ng 2015). The main criterion of the choice of the suit- Records excluded on title, abstract, and relevance (n = able leaves for food packaging is their availability (Ng 2015; 1134) Onzo et al. 2013). Other criteria are their suppleness after treatments, their wideness, their effect on organoleptic prop- erties of food, and the facility of being treated, preserved and transported (Mustafa et al. 2012; Ng 2015; Onzo et al. Full records assessed 2013). Also, in some European countries, the feasibility of for eligibility introducing leaf packaging for food purposes has been stud- (n = 192) ied (Boko et al. 1997). Eligibility Leaf packaging could constitute an adequate solution Records excluded at full text to the problems due to plastic food packaging in develop- because the full text is not ing countries. To promote leaf packaging, it is important available or the study does not to have a better overview on the plant species in terms of address plant leaves as packaging materials of food their botanical richness, the locations where they are most products (n = 119) encountered, and their usage worldwide. In addition, infor- mation on the food types packed in plant leaves, the pre- Included treatments of the leaves before their use, the effect of leaf Studies included packaging on organoleptic quality of food, the antimicrobial (n = 73) and mechanical properties of leaf packaging, the physical and mechanical properties of leaves used to wrap foods, the environmental importance of leaf packaging, the toxicol- Fig. 1  PRISMA flow diagram showing the selection of studies on ogy of leaf packaging, and further applications of leaves leaf-packaging process 13 Development and use of food packaging from plant leaves in developing countries or libraries, graduate dissertations, reports from public and in the tropics, the plant leaves are usually bigger than in other private sectors) were also consulted. During the literature climates. Besides, plant leaves are used because of their bio- search, we did not make any restrictions regarding language degradability, their medicinal properties, and low costs (Boko or year of publication. et al. 1997; Harijati et al. 2013; Lascurain et al. 2017; Men- Identified records from literature were exported into sah et al. 2012; Ng 2015; Onzo et al. 2013, 2016; Zakariah the citation manager Zotero 5.0.60 where duplicate entries et al. 2019). In addition, some of the plants including maize where merged. The 1326 obtained records (Fig. 1) were and banana are widespread and abundant because they are screened for relevance based on their title and abstract. At also highly consumed by humans. Although more than 200 this step, all studies published in other languages than Eng- plant species used as leaf packaging were found in this study, lish or French were excluded. The selected full texts were the real number of species used to wrap food is likely higher then reviewed in detail to retain the relevant documents for because some are probably scientifically unknown and not yet our study. The main inclusion criteria were that the study botanically described (Ng 2015). In fact, several plant species must address plant leaves as food packaging materials. How- used to wrap food products are still entirely wild and collected ever, these plant leaves may also be used for other purposes only when necessary. For example, only 20% of plant species (e.g. medicinal use). Studies of interest were those address- used as leaf packaging in Benin (n = 65) are cultivated (Onzo ing one or more of the following aspects: types of foods et al. 2016). The number and the type of plant species used to packed in plant leaves, pre-treatments undergone by the wrap food products can vary even within a country. For exam- leaves before their use, effect of packaging leaf on organo- ple, plant species used to wrap zongzi, a traditional product of leptic quality of food products, antimicrobial and mechani- cultural and dietary significance in China, were more diverse cal properties of leaf packaging, physical and mechanical in the South of the country than in the North (Lin et al. 2019). properties of leaves used to wrap foods, environmental Similarly, different plant species are used to wrap lio (tradi- importance of leaf packaging, toxicology of leaf packag- tional maize-fermented product) in different regions of Benin ing, and further applications of leaves to reduce the use of (Onzo et al. 2013). These different use of plant species for the of fossil based plastics. Studies dealing with leaf extract to same product can be explained by the availability and cultural develop other types of packaging materials were excluded in diversity (Lin et al. 2019; Onzo et al. 2013). Figure 2 shows this study. The synthesis of the selected relevant literature is some images of leaves used to wrap foods in Benin. presented in this paper. 4 Food types packed in plant leaves 3 Plant species used in food packaging Various food products of of both plant and animal origin can be packed in plant leaves (Table 1). However, they are Based on our literature search, 220 plant species from 50 used more to pack traditional foods in Africa, Asia, and botanical families were identified. Among the recorded South America. Foods packaged in plant leaves are solid or botanical families from Africa, Asia, and South America, semi-liquid (Onzo et al. 2013). Some of them are packaged poaceae were most widely used for food packaging (n = 26). raw before cooking or baking while others are wrapped in Followed by marantaceae (n = 24), malvaceae (n = 19), leaves after cooking while they are still hot (Adejumo and arecaceae (n = 17), fabaceae (n = 14) moraceae (n = 14), Ola 2008; Onzo et al. 2013). musaceae (n = 12) and zingiberaceae (n = 11) which con- In Africa, various cereal fermented foods (akassa, kenkey, tains each at least 10 plant species (Table 1). More than lio etc.) still are mostly packed in plant leaves (Mensah et al. a third (36.0%) of the recorded botanical families (n = 50) 2012; Onzo et al. 2013). In Asia, rice-based traditional food came from Africa, while 4.0% were from South America products such as nasi lemak (Malaysia), nagasari (Indone- (Table 1). At species level, the leaves of Zea mays (Poaceae) sia), zongzi (China) are packaged in plant leaves (Lin et al. and Musa paradisiaca (Musaceae) were most widely used as 2019; Harijati et al. 2013; Ng 2015). In South America, food packaging in all three regions (Africa, Asia and South tamale, a maize-based traditional food is packaged in plant America). This is in agreement with the report by Lascurain leaves (Lascurain et al. 2017). et al. (2017), who showed that the two most common leaves used for wrapping tamale (traditional maize-based product) in Mexico were banana (Musa paradisiaca) and maize (Zea 5 Pre‑treatments of the leaves before their mays) leaves. The banana leaf is also the most popular leaf use in food packaging for food wrapping in Indonesia (Harijati et al. 2013; Zaka- riah et al. 2019). Before using the leaves as packaging materials, they undergo According to Ng (2015), plant leaves are more used as various pre-treatments (Table 2). In fact, in their natu- food packaging in Africa, Asia and South America because ral state, some leaves break easily and are not suitable for 13  Table 1  Plants used to wrap various food products worldwide No Plant species Botanical families Country Continent Food product Food category References 13 1 Adenodolichos paniculatus Fabaceae Benin Africa Akassa, lio etc Maize-based product Onzo et al. (2016) 2 Agyrea nervosa Convolvulaceae Benin Africa Akassa, lio etc Maize-based product Onzo et al. (2016) 3 Albizia adianthifolia Mimosaceae Nigeria Africa Various foods Various Ebigwai et al. (2014) 4 Alchornea cordifolia Euphorbiaceae Benin Africa Akassa, lio akpan, gowé abla, Cereal-based product, legume- Gbesso et al. (2015) ablo, kandji based product 5 Alpinia abundiflora Zingiberaceae China Asia Zongzi rice-based product Lin et al. (2019) 6 Alpinia odontonema Zingiberaceae West Papua, Asia Sweet potatoes Tubers Milliken (1992) Indonesia 7 Alpinia pricei Zingiberaceae China Asia Zongzi Rice-based product Lin et al. (2019) 8 Alpinia zerumbet Zingiberaceae China Asia Zongzi Rice-based product Lin et al. (2019) 9 Ampelocissus leonensis Vitaceae Benin Africa Akassa, lio etc Maize-based product Onzo et al. (2016) 10 Ampelocissus pentaphylla Vitaceae Benin Africa Akassa, lio etc Maize-based product Onzo et al. (2016) 11 Amomum villosum Zingiberaceae China Asia Zongzi Rice-based product Lin et al. (2019) 12 Annona senegalensis Annonaceae Benin Africa Akassa, lio etc Maize-based product Onzo et al. (2016) 13 Anthocleista djalonensis Gentianaceae Benin Africa Akassa, lio etc Maize-based product Onzo et al. (2016) 14 Anthocleista vogelii Gentianaceae Benin Africa Akassa, lio akpan, gowé abla, Cereal-based product, legume- Onzo et al. (2013), Onzo et al. ablo, kandji based product (2016), Gbesso et al. (2015) 15 Anthurium schlechtendalii Araceae Mexico South Tamale Maize-based product Lascurain et al. (2017) America 16 Anthurium sp. Araceae Mexico South Tamale Maize-based product Lascurain et al. (2017) America 17 Antiaris toxicaria Moraceae Benin Africa Lio Maize-based product Onzo et al. (2013), Onzo et al. (2016) 18 Areca catechu Arecaceae India Asia Various foods hot and cold Various Kora (2019) 19 Arundo donax Poaceae China Asia Zongzi Rice-based product Lin et al. (2019) 20 Aspidistra elatior Liliaceae China Asia Zongzi Rice-based product Lin et al. (2019) 21 Aspidistra oblanceifolia Liliaceae China Asia Zongzi Rice-based product Lin et al. (2019) 22 Aspidistra sichuanensis Liliaceae China Asia Zongzi Rice-based product Lin et al. (2019) 23 Aspidistra zongbayi Liliaceae China Asia Zongzi Rice-based product Lin et al. (2019) 24 Bambusa sp. Poaceae Japan Asia Sasa-Dango Rice-based product and Mustafa et al. (2012) legume-based product 25 Betel palm Arecaceae Malaysia Asia Various foods Various Mustafa et al. (2012) 26 Blighia sapida Sapindaceae Benin Africa Lio Maize-based product Onzo et al. (2013), Onzo et al. (2016) 27 Borassus flabellifer Arecaceae India Asia Meat and fruits Meat-based products and Kora (2019) fruits 28 Butea frondosa Fabaceae India Asia Various foods Various Boko et al. (1997) 29 Butea monosperma Fabaceae India Asia Rice Rice-based product Boko et al. (1997), Kora M. Hounsou et al. (2019)  Table 1  (continued) No Plant species Botanical families Country Continent Food product Food category References 30 Calathea allouia Marantaceae Honduras South Bean, manioc Legume-based product, tubers Lentz (1993) America 31 Calathea insignis Marantaceae Honduras South Various foods Various Lentz (1993) America 32 Calathea lutea Marantaceae Mexico South Tamale Maize-based product Lascurain et al. (2017) America 33 Callicarpa pentandra Lamiaceae West Papua, Asia Banana Fruits and vegetables Milliken (1992) Indonesia 34 Calopogonium mucunoides Fabaceae Benin Africa Akassa, lio Maize-based product Onzo et al. (2013), Onzo et al. (2016) 35 Calotropis procera Apocynaceae Benin Africa Various foods Various Onzo et al. (2016) 36 Canna indica Cannacea Benin Africa Akassa, lio etc Maize-based product Onzo et al. (2013), Onzo et al. (2016) Mexico South Tamale Maize-based product Lascurain et al. (2017) America Nigeria Africa Corn jell-o, and other foods Maize-based product and Adeogun and Adekunle other food groups (2018), Adeogun et al. (2017) 37 Cinnamomum malabatrum Lauraceae India Asia Therali appam Rice-based product Kora (2019) 38 Cissus populnea Vitaceae Benin Africa Various food Various Onzo et al. (2016) Development and use of food packaging from plant leaves in developing countries 39 Clerodendrum polycephalum Verbenaceae Benin Africa Various food Various Onzo et al. (2016) 40 Cocos nucifera Arecaceae China Asia Zongzi rice-based product Lin et al. (2019) 41 Cocos sp. Arecaceae Indonesia Asia Rice Rice-based product Amalia and Davidescu (2019), Malaysia Asia Ketupat nasid, rice and other Rice-based product and other Mustafa et al. (2012), Ng foods food groups (2015), Raji et al. (2017) The Philippines Asia suman Rice-based product Cornelio (2009) 42 Cola acuminata Malvaceae Nigeria Africa Various foods Various Adeogun et al. (2017) 43 Cola cordifolia Malvaceae Côte d’Ivoire Africa Dockounou, attieke, foutou, Cereal-based product, root Onzo et al. (2015a) bolo fari, akassa, etc and tuber-based product etc 44 Cola gigantean Malvaceae Benin Africa Various foods various Onzo et al. (2016) 45 Cola millenii Malvaceae Benin Africa Various foods various Onzo et al. (2016) 46 Cola nitida Malvaceae Nigeria Africa Various foods various Adeogun et al. (2017), Ajao et al. (2022) 47 Colocasia esculenta Araceae India Asia Patrode and alu chi wadi Steam cooking and oil Kora (2019) 48 Combretum collinum Combretaceae Nigeria Africa Various foods various Adeogun et al. (2017) Benin Africa Various foods Various Onzo et al. (2016), 49 Corchorus capsularis Malvaceae China Asia Zongzi Rice-based product Lin et al. (2019), 50 Cordia millenii Boraginaceae Nigeria Africa Various foods Various Ariyo et al. (2018) 13  Table 1  (continued) No Plant species Botanical families Country Continent Food product Food category References 13 51 Cordyline fruticosa Asparagaceae Indonesia Asia Rice Rice-based product Amalia and Davidescu (2019); 52 Corypha lecomtei Arecaceae Malaysia Asia Various foods Various Mustafa et al. (2012), 53 Costus afer Costaceae Benin Africa Various foods Various Onzo et al. (2016) 54 Curcuma longa Zingiberaceae India Asia Patoli, Steam cooking of sweet dish Kora (2019) Benin Africa Various foods Various Onzo et al. (2016) 55 Cussonia arborea Araliaceae Benin Africa Lio, akassa etc Maize-based product etc Onzo et al. (2013), Onzo et al. (2016) 56 Cussonia barteri Araliaceae Benin Africa various foods Various Onzo et al. (2016) 57 Cyrtosperma senegalense Araceae Benin Africa Various foods Various Onzo et al. (2016) 58 Daniellia oliveri Fabaceae Benin Africa Lio, akassa, ablo Maize-based product Onzo et al. (2013), Onzo et al. (2016) 59 Dendrocalamus giganteus Poaceae China Asia Zongzi rice-based product Lin et al. (2019) 60 Dendrocalamus latiflorus Poaceae China Asia Zongzi rice-based product Lin et al. (2019) 61 Detaricum macrocarpum Fabaceae Benin Africa Various foods Various Onzo et al. (2016) 62 Dinochloa sublaevigata Poaceae Malaysia,China Asia Rice Rice-based product Ng (2015) 63 Dioscorea alata Dioscoreaceae Benin Africa Various foods Various Onzo et al. (2016) 64 Donax canniformis Marantaceae Malaysia Asia Various foods Various Mustafa et al. (2012) 65 Elaeis guineensis Arecaceae Benin Africa Lio, afitin etc Maize-based product and Onzo et al. (2013), Onzo et al. legume-based product (2016) 66 Eremospatha haullevilleana Arecaceae Congo Africa Various foods Various Mbale et al. (2020) 67 Eremospatha cabrae Arecaceae Congo Africa Various foods Various Mbale et al. (2020) 68 Etlingera sp. Zingiberaceae West Papua, Asia Sweet potatoes leaves Fruits and vegetables Milliken (1992) Indonesia 69 Evodia glabrifolia Rutaceae China Asia Zongzi Rice-based product Lin et al. (2019) 70 Fargesia fractiflexa Poaceae China Asia Zongzi Rice-based product Lin et al. (2019) 71 Ficus auriculata Moraceae India Asia Various food Various Lin et al. (2019) 72 Ficus bengalensis Moraceae India Asia various food Various Lin et al. (2019) 73 Ficus capensis Moraceae Benin Africa Lio Maize-based product Onzo et al. (2013), Onzo et al. (2016) 74 Ficus dammaropsis Moraceae West Papua, Asia Various foods Various Milliken (1992) Indonesia 75 Ficus embellata Moraceae Benin Africa Lio Maize-based product Onzo et al. (2013), Onzo et al. (2016) 76 Ficus ingens Moraceae Benin Africa Various foods Various Onzo et al. (2016) 77 Ficus phita Moraceae Benin Africa various foods Various Onzo et al. (2016) M. Hounsou et al.  Table 1  (continued) No Plant species Botanical families Country Continent Food product Food category References 78 Ficus platyphylla Moraceae Benin Africa Various foods Various Onzo et al. (2016) Côte d’Ivoire Africa Claclo, doklu, Various Onzo et al. (2015a) alloco, bêdêcouman etc 79 Ficus polita Moraceae Benin Africa various foods Various Onzo et al. (2016) 80 Ficus religiosa Moraceae India Asia Various food Various Kora (2019) 81 Ficus sycomorus Moraceae Benin Africa various foods Various Onzo et al. (2016) 82 Ficus virens Moraceae India Asia Various food Various Kora (2019) 83 Firmiana platanifolia Malvaceae China Asia Zongzi Rice-based product Lin et al. (2019) 84 Gmelina arborea Verbenaceae Benin Africa Akassa, lio etc Maize-based product Onzo et al. (2013), Onzo et al. (2016) 85 Goeppertia misantlensis Marantaceae Mexico South Tamale Maize-based product Lascurain et al. (2017) America 86 Goeppertia ovandensis Marantaceae Mexico South Tamale Maize-based product Lascurain et al. (2017) America 87 Haumania liebrechtsiana Marantaceae Congo Africa Various foods Various Mbale et al. (2020) 88 Hedychium coronarium Zingiberaceae China Asia Zongzi Rice-based product Lin et al. (2019) 89 Heliconia bihai Heliconiaceae Colombia South Guava paste Fruits and vegetables Forero-Cabrera et al. (2017) America 90 Heliconia latispatha Heliconiaceae Mexico South Tamale Maize-based product Lascurain et al. (2017) Development and use of food packaging from plant leaves in developing countries America 91 Heliconia schiedeana Heliconiaceae Mexico South Tamale Maize-based product Lascurain et al. (2017) America 92 Heliconia uxpanapensis Heliconiaceae Mexico South Tamale Maize-based product Lascurain et al. (2017) America 93 Heracleum pastinacifolium Apiaceae Turkey Asia Various foods Various Güneş and Özhatay (2011) 94 Hibiscus tiliaceus Malvaceae Indonesia Asia Tempeh Legume-based products Utama et al. (2018) 95 Hildegar diabarteri Malvaceae Benin Africa Various foods Various Onzo et al. (2016) 96 Holarrhena floribunda Apocynaceae Benin Africa Lio Maize-based product Onzo et al. (2013), Onzo et al. (2016) 97 Hornstedtia scottiana Zingiberaceae West Papua, Asia Sweet potatoes Tubers Milliken (1992) Indonesia 98 Icacina tricantha Icacinaceae Benin Africa Akassa, lio akpan, gowé abla, Cereal-based product, legume- Gbesso et al. (2015), Onzo ablo, kandji based product et al. (2013), Onzo et al. (2016) 99 Indocalamus guangdongensis Poaceae China Asia Zongzi Rice-based product Lin et al. (2019) 100 Indocalamus herklotsii Poaceae China Asia Zongzi Rice-based product Lin et al. (2019) 101 Indocalamus latifolius Poaceae China Asia Zongzi Rice-based product Lin et al. (2019) 102 Indocalamus tessellatus Poaceae China Asia Zongzi Rice-based product Lin et al. (2019) 13  Table 1  (continued) No Plant species Botanical families Country Continent Food product Food category References 13 103 Isoberlinia doka Fabaceae Benin Africa Lio, akassa, ikaraewa etc Cereal-based and legume- Onzo et al. (2013), Onzo et al. based product (2016) 104 Isoberlinia grandiflora Fabaceae Benin Africa Various foods Various Onzo et al. (2016) 105 Isoberlinia tomentosa Fabaceae Benin Africa Various foods Various Onzo et al. (2016) 106 Jatropha curcas Euphorbiaceae Benin Africa Various foods Various Onzo et al. (2016) 107 Lablab purpureus Fabaceae India Asia various various Kora (2019) 108 Lagenaria siceraria Cucurbitaceae Benin Africa Various foods Various Onzo et al. (2016) 109 Lannea microcarpa Anacardiaceae Benin Africa Lio Maize-based product Onzo et al. (2013), Onzo et al. (2016) 110 Lasimorpha senegalensis Araceae Benin Africa Various foods Various Gbesso et al. (2015), Onzo et al. (2013), Onzo et al. (2016), Zannou et al. (2016) Congo Africa Various foods Various Mbale et al. (2020) 111 Lepironia articulata Cyperaceae Malaysia Asia Various foods Various Mustafa et al. (2012) 112 Licuala palas Arecaceae Malaysia Asia Various foods Various Mustafa et al. (2012) 113 Licuala sp. Arecaceae Malaysia Asia Rice Rice-based product Ng (2015) 114 Licuala spinosa Arecaceae Malaysia Asia Various foods Various Mustafa et al. (2012) 115 Livistona chinensis Arecaceae China Asia Zongzi Rice-based product Lin et al. (2019) 116 Macaranga peltata Euphorbiaceae India Asia Ilayappam, ada Rice-based product Kora (2019) Sri-Lanka Asia Helapa Sweet treat Ashton et al. (1997) 117 Macaranga sp. Euphorbiaceae Malaysia Asia Rice Rice-based product Mustafa et al. (2012) 118 Madhuca indica Sapotaceae India Asia Various foods various Boko et al. (1997) 119 Magnolia officinalis Magnoliacee China Asia Zongzi Rice-based product Lin et al. (2019) 120 Malva neglecta Malvaceae Turkey Asia Various foods Various Güneş and Özhatay (2011) 121 Mangifera indica Anacardiaceae Benin Africa Various foods Various Onzo et al. (2016) 122 Manihot esculenta Euphorbiaceae Benin Africa Lio Maize-based product Onzo et al. (2013), Onzo et al. (2016) 123 Manihot glaziovii Euphorbiaceae Benin Africa Lio Maize-based product Onzo et al. (2013), Onzo et al. (2016) 124 Marantochloa congensis Marantaceae Congo Africa Various foods Various Mbale et al. (2020) 125 Marantochloa cuspidata Marantaceae Ghana Africa Kenkey Maize-based product Mensah et al. (2012) 126 Marantochloa sp. Marantaceae Ghana Africa Agidi Maize-based product Dzikunoo et al. (2021) 127 Marantodea sp. Marantaceae Nigeria Africa Various foods Various Adejumo and Ola (2008) 128 Megaphrynium macros- Marantaceae Congo Africa Various foods Various Koto-te-Nyiwa et al. (2019), tachyum Mbale et al. (2020) Nigeria Africa Corn jell-o, and other foods Maize-based product and Adeogun and Adekunle other food groups (2018), Adeogun et al. (2017), Ajao et al. (2022) M. Hounsou et al.  Table 1  (continued) No Plant species Botanical families Country Continent Food product Food category References 129 Miscanthus floridulus Poaceae China Asia Zongzi Rice-based product Lin et al. (2019) 130 Mitragyna ciliata Rubiaceae Nigeria Africa Various foods Various Ajao et al. (2022) 131 Mitragyna stipulos Rubiaceae Nigeria Africa Various foods Various Aiyeloja and Ajewole (2006) 132 Monocladus amplexicaulis Poaceae China Asia Zongzi Rice-based product Lin et al. (2019) 133 Mucuna pruriens Fabaceae Benin Africa Various foods Various Onzo et al. (2016) 134 Musa acuminata Musaceae Benin Africa Akassa Maize-based product Zannou et al. (2016) China Asia Zongzi Rice-based product Lin et al. (2019) Côte d’Ivoire Africa Various foods Various Onzo et al. (2013), Onzo et al. (2015a) Nigeria Africa Corn jell-o maize-based product Adeogun and Maroyi (2018), 135 Musa balbisiana Musaceae China Asia Zongzi Rice-based product Lin et al. (2019) Indonesia Asia Fruit Fruit and vegetables Hapsari et al. (2017) 136 Musa basjoo Musaceae China Asia Zongzi Rice-based product Lin et al. (2019) 137 Musa branchycarpa Musaceae Indonesia Asia Nagasari, lemper etc Rice-based product Harijati et al. (2013) 138 Musa cavendishi Musaceae Indonesia Asia Nagasari, lemper etc Rice-based product Harijati et al. (2013) 139 Musa chinensis Musaceae Benin Africa Akassa, lio etc Maize-based product Onzo et al. (2013), Onzo et al. (2016) 140 Musa itineras Musaceae China Asia Zongzi Rice-based product Lin et al. (2019) 141 Musa nana Musaceae China Asia Zongzi Rice-based product Lin et al. (2019) Development and use of food packaging from plant leaves in developing countries 142 Musa paradisiaca Musaceae Colombia South Lulo Fruits and vegetables Forero-Cabrera et al. (2017) America Indonesia Asia Nagasari, lemper etc rice-based products Harijati et al. (2013) India Asia Various foods various Kora (2019) Côte d’Ivoire Africa Dockounou, attieke foutou, le Cereal-based product, root Onzo et al. (2015a) bolo fari, akassa, le Claclo, and tuber-based product, doklu, alloco, bêdêcouman legume-based product rice Ghana Africa Kenkey Maize-based product Mensah et al. (2012) Nigeria Africa Moi-moi, okpa and various legume-based products and Adegunloye et al. (2006), other foods other food groups Adeogun et al. (2017), Ibeg- bulem et al. (2004) Mexico South Tamale Maize-based product Lascurain et al. (2017) America 143 Musa sapientum Musaceae Indonesia Asia Nagasari, lemper etc rice-based products Harijati et al. (2013) China Asia Zongzi Rice-based product Lin et al. (2019) Benin Africa Akassa, ablo, kandji, aboete Cereal-based product, root Onzo et al. (2013), Onzo et al. kpo, adjagbé etc and tuber-based product etc (2016) Nigeria Africa Various foods Various Adeogun et al. (2017) 13  Table 1  (continued) No Plant species Botanical families Country Continent Food product Food category References 13 144 Musa sinensis Musaceae Benin Africa Akassa, fruits and vegetables Cereal-based products, fruits Boko et al. (1997) and vegetables Togo Africa Akassa, fruits and vegetables Cereal-based products, fruits Boko et al. (1997) and vegetables Nigeria Africa Akassa, fruits and vegetables Cereal-based products, fruits Boko et al. (1997) etc and vegetables 145 Musa sp. Musaceae Nigeria Africa Akassa, madidi, ofada Cereal-based product Adebola et al. (2017), Ajayi et al. (2019), Ezeudu et al. (2021) Ethiopia Africa Papaya Fruits and vegetables Azene et al. (2014) Malaysia, China Asia Nasi lemak Rice-based product, fish, Ng (2015) Indonesia Asia Dangke, tempeh, various other Dairy product, legume-based Ardhianto and Hardjana foods product and other food (2016), Erdiansyah et al. groups (2022), Purwadaria et al. (2016), Utama et al. (2018), Zakariah et al. (2019) Indo-Malesian Asia Various foods Various Kennedy (2009) area India Asia Guava (Psidium guajava L.) Fruits and vegetables, other Chandra et al (2011), Hegde fruits, other foods food groups et al. (2018) Benin Africa Various foods various Gbesso et al. (2015) Congo Africa Various foods Various Mbale et al. (2020) Ghana Africa Fante Maize-based product Dzikunoo et al. (2021) Malaysia Asia Nasi lemak and other foods rice-based product, fish and Ibrahim and Jamaluddin other food groups (2007), Raji et al. (2017) Myanmar Asia Hinhtou Rice-based product Moe (2012) Sri Lanka Asia Various foods Various foods Ashton et al. (1997) Uganda Africa banana Fruits and vegetables Asada (2019) The Philippines Asia suman Rice-based product Cornelio (2009) West Papua, Asia Various foods Various Milliken (1992) Indonesia 146 Napoleona imperialis Lecythidaceae Benin Africa Fruit Fruits and vegetables Boko et al. (1997) 147 Nelumbo nucifera Nelumbonaceae China Asia Rice, Zongzi Rice-based product Lin et al. (2019), Ng (2015) India Asia Meat and cooked food Meat-based products Kora (2019) 148 Nelumbo sp. Nelumbonaceae India Asia Various foods Various Hegde et al. (2018) 149 Nypa fruticans Arecaceae Malaysia Asia Various foods Various Mustafa et al. (2012) 150 Oreopanax echinops Araliaceae Mexico South Tamale Maize-based product Lascurain et al. (2017) America M. Hounsou et al.  Table 1  (continued) No Plant species Botanical families Country Continent Food product Food category References 151 Oreopanax flaccidus Araliaceae Mexico South Tamale Maize-based product Lascurain et al. (2017) America 152 Oreopanax capitatus Araliaceae Mexico South Tamale Maize-based product Lascurain et al. (2017) America 153 Pandanus amaryllifolius Pandanaceae India Asia Mude Rice-based product Kora (2019) Malaysia Asia Kuih (Tepung Pelita) Rice-based product Mustafa et al. (2012) 154 Pandanus austrosinensis Pandanaceae China Asia Zongzi Rice-based product Lin et al. (2019) 155 Pandanus candelabrum Pandanaceae Nigeria Africa moi-moi and okpa legume-based products Ibegbulem et al. (2004) 156 Pandanus sp. Pandanaceae Malaysia Asia Various foods Various Ibrahim and Jamaluddin (2007) The Philippines Asia suman Rice-based product Cornelio (2009) 157 Pandanus tectorius Pandanaceae China Asia Zongzi Rice-based product Lin et al. (2019) Indonesia Asia Rice Rice-based product Amalia and Davidescu (2019); 158 Paveta crassipes Rubiaceae Benin Africa Various foods Various Onzo et al. (2016) 159 Pentaclethra macrophylla Fabaceae Nigeria Africa Various foods Various Ariyo et al. (2018) 160 Perilla frutescens Lamiaceae China Asia Zongzi Rice-based product Lin et al. (2019) 161 Persea americana Lauraceae Mexico South Tamale Maize-based product Lascurain et al. (2017) America 162 Phanera vahlii Fabaceae India Asia Idli, meat Rice-based product, meat Kora (2019) based product Development and use of food packaging from plant leaves in developing countries 163 Phoenix sp. Arecaceae Iran Asia Date fruits and vegetables Askarinejad et al. (2018) 164 Phragmites australis Poaceae China Asia Zongzi Rice-based product Lin et al. (2019) 165 Phrynium capitatum Marantaceae China Asia Zongzi Rice-based product Lin et al. (2019) 166 Phrynium hainanense Marantaceae China Asia Zongzi Rice-based product Lin et al. (2019) 167 Phrynium placentarium Marantaceae China Asia Zongzi Rice-based product Lin et al. (2019) 168 Phrynium pubinerve Marantaceae China Asia Various foods Various Li et al. (2015) 169 Phrynium sp. Marantaceae West Papua, Asia Various foods Various Milliken (1992) Indonesia 170 Phyllostachys bambusoides Poaceae China Asia Zongzi Rice-based product Lin et al. (2019) Japan Asia Various foods Various Nawa and Ishimura (2004) 171 Phyllostachys heteroclada Poaceae China Asia Zongzi Rice-based product Lin et al. (2019) 172 Phyllostachys heterocycla Poaceae China Asia Zongzi Rice-based product Lin et al. (2019) Japan Asia Various foods Various Nawa and Ishimura (2004) 173 Piliostigma reticulatum Fabaceae Nigeria Africa Various foods various Adeogun et al. (2017) 174 Piliostigima thonningii Fabaceae Benin Africa Various foods Various Onzo et al. (2016) Côte d’Ivoire Africa Various foods Various Onzo et al. (2015a) 175 Piper sarmentosum Piperaceae China Asia Zongzi Rice-based product Lin et al. (2019) 13  Table 1  (continued) No Plant species Botanical families Country Continent Food product Food category References 13 176 Pleioblastus amarus Poaceae China Asia Zongzi Rice-based product Lin et al. (2019) 177 Podocarpus nagi Podocarpaceae China Asia Zongzi Rice-based product Lin et al. (2019) 178 Polygonum senegalense Polygonaceae Benin Africa Akassa etc Maize-based product Onzo et al. (2013), Onzo et al. (2016), 179 Pouteria alnifolia Sapotaceae Benin Africa Akassa, Maize-based product Gbesso et al. (2015), Onzo et al. (2013), Onzo et al. (2016), 180 Psidium sp. Myrtaceae Indonesia Asia Rice Rice-based product Amalia and Davidescu (2019), 181 Pterospermum acerifolium Malvaceae India Asia Various foods Various Kora (2019) 182 Quararibea funebris Malvaceae Mexico South Tamale Maize-based product Lascurain et al. (2017) America 183 Quercus candicans Fagaceae Mexico South Tamale Maize-based product Lascurain et al. (2017) America 184 Quercus dentata Fagaceae China Asia Zongzi Rice-based product Lin et al. (2019) 185 Renealmia mexicana Zingiberaceae Mexico South Tamale Maize-based product Lascurain et al. (2017) America 186 Rhapis excelsa Arecaceae China Asia Zongzi Rice-based product Lin et al. (2019) 187 Saccharum officinarum Poaceae China Asia Zongzi Rice-based product Lin et al. (2019) Congo Africa Various foods Various Mbale et al. (2020) 188 Sarcocephalus latifolius Rubiaceae Benin Africa Akassa Maize-based product Onzo et al. (2013), Onzo et al. (2016) 189 Sarcophrynium brachystachys Marantaceae Congo Africa Various foods Various Koto-te-Nyiwa et al. (2019) Nigeria Africa Various foods Various Aiyeloja and Ajewole (2006), Ajao et al. (2022) 190 Sarcophrynium schweinfurthi- Congo Africa Various foods Various Mbale et al. (2020) anum 191 Sasa palmata Poaceae Japan Asia Various foods Various Nawa and Ishimura (2004) 192 Sasa veiitchi Poaceae Japan Asia Various foods Various Nawa and Ishimura (2004) 193 Schizostachyum brachycladum Poaceae Malaysia Asia Various foods Various Ibrahim and Jamaluddin (2007) 194 Shorea robusta Dipterocarpaceae India Asia Boiled lentils Legume-based products Kora (2019) 195 Siphonochilus aethiopicus Zingiberaceae Benin Africa Various foods Various Onzo et al. (2016) 196 Smilax sp. Smilacaceae Mexico South Tamale Maize-based product Lascurain et al. (2017) America 197 Sorghum bicolor Poaceae China Asia Zongzi Rice-based product Lin et al. (2019) Benin Africa Various foods Various Onzo et al. (2016) 198 Spathoglottis plicata Orchidaceae West Papua, Asia Various foods Various Milliken (1992) Indonesia M. Hounsou et al.  Table 1  (continued) No Plant species Botanical families Country Continent Food product Food category References 199 Sterculia nobilis Malvaceae China Asia Zongzi Rice-based product Lin et al. (2019) 200 Sterculia setigera Malvaceae Benin Africa Various foods Various Onzo et al. (2016) 201 Sterculia tragacantha Malvaceae Benin Africa Akassa, Ablo, Abla etc Legume-based products and Gbesso et al. (2015), Onzo maize-based product et al. (2013), Onzo et al. (2016), Ghana Africa Kenkey Maize-based product Mensah et al. (2012) 202 Stromanthe hjalmarssonii Marantaceae Honduras South fruits fruits and vegetables Lentz (1993) America 203 Stromanthe macrochlamys Marantaceae Mexico South Tamale Maize-based product Lascurain et al. (2017) America 204 Tachyphrynium braunianum Marantaceae Benin Africa Various foods Various Gbesso et al. (2015) 205 Tectona grandis Lamiaceae Benin Africa Akassa, fruits and vegetables, Cereal-based products, Boko et al. (1997), Gbesso ikaraekpa etc legume-based product fruits et al. (2015), Onzo et al. and vegetables (2013), Onzo et al. (2016), Zannou et al. (2016) Indonesia Asia Rice/nagasari, lemper/ Tempeh Rice-based product/ legume- Amalia and Davidescu (2019), etc based products Harijati et al. (2013), Ng (2015), Utama et al. (2018) India Asia Pelakai gatti, guava (Psidium Rice-based product, fruits and Chandra et al. (2011), Kora guajava L.) vegetables (2019) Côte d’Ivoire Africa Dockounou, attieke, foutou, Cereal-based product, root Onzo et al. (2015a) Development and use of food packaging from plant leaves in developing countries bolo fari, akassa, etc and tuber-based product, legume-based product Nigeria Africa Various foods Various Adegunloye et al. (2006), Adeogun and Maroyi (2018), Adekunle et al. (2012), Aiye- loja and Ajewole (2006), Ajao et al. (2022), Akanni (2013) 206 Terminalia catappa Combretaceae India Asia Various foods various Kora (2019) China Asia Zongzi Rice-based product Lin et al. (2019) 207 Thalia geniculata Marantaceae Benin Africa Lio, akassa etc Maize-based product Gbesso et al. (2015), Onzo et al. (2013), Zannou et al. (2016) Côte d’Ivoire Africa Dockounou, attieke, foutou, Cereal-based product, root Onzo et al. (2015a) bolo fari, and tuber-based product, akassa, etc legume-based product Congo Africa Various foods Various Mbale et al. (2020) Mexico South Tamale Maize-based product Lascurain et al. (2017) America 13  Table 1  (continued) No Plant species Botanical families Country Continent Food product Food category References 13 208 Thaumatococcus daniellii Marantaceae Côte d’Ivoire Africa Dockounou, attieke, foutou, Cereal-based product, root Onzo et al. (2015a) bolo fari, and tuber-based product, akassa, etc legume-based product Nigeria Africa Corn jell-o, and other foods Maize-based product and Adeogun and Adekunle other food groups (2018), Adeogun et al. (2017), Adegunloye et al. (2006), Adekunle et al. (2012), Aiyeloja and Ajewole (2006), Ajao et al. (2022), Akanni (2013), Babalola (2009) 209 Theobroma cacao Malvaceae Côte d’Ivoire Africa Dockounou, attieke, foutou, Cereal-based product, root Onzo et al. (2015a) bolo fari, and tuber-based product, akassa, etc legume Nigeria Africa Various foods various Adeogun et al. (2017) 210 Thespesia populnea Malvaceae Nigeria Africa various foods various Adejumo and Ola (2008) Ghana Africa Kaafa, abolo, apitsi Maize-based product Dzikunoo et al. (2021), Men- sah et al. (2012) 211 Thysanolaena latifolia Poaceae China Asia Various foods Various Li et al. (2015) 212 Thysanolaena maxima Poaceae West Papua, Asia Dead birds of paradise Meat-based products Milliken (1992) Indonesia China Asia Zongzi Rice-based product Lin et al. (2019) 213 Tilia tuan Malvaceae China Asia Zongzi Rice-based product Lin et al. (2019) 214 Trachycarpus fortunei Arecaceae China Asia Zongzi Rice-based product Lin et al. (2019) 215 Triplochiton scleroxylon Malvaceae Benin Africa Lio Maize-based product Onzo et al. (2013), Onzo et al. (2016) 216 Uapaca togoensis Phyllanthaceae Benin Africa various foods various Onzo et al. (2016) 217 Vernicia fordii Euphorbiaceae China Asia Zongzi Rice-based product Lin et al. (2019) 218 Vitellaria paradoxa Sapotaceae Benin Africa Various foods Various Onzo et al. (2016) 219 Zea mays Poaceae China Asia Zongzi Rice-based product Lin et al. (2019) Benin Africa Come, fruit and vegetables etc Cereal based product, fruits Onzo et al. (2016) and vegetables Côte d’Ivoire Africa Various Various Onzo et al. (2015a) Indonesia Asia Rice Rice-based product Amalia and Davidescu (2019), Nigeria Africa Various foods Various Adejumo and Ola (2008) Ghana Africa Kenkey, Ga kenkey Maize-based product Dzikunoo et al. (2021), Men- sah et al. (2012) Mexico South Tamale Maize-based product Lascurain et al. (2017) America M. Hounsou et al.  Development and use of food packaging from plant leaves in developing countries food packaging (Boko et al. 1997). Therefore, leaves need pre-treatments for softening resistance and malleability. In China, leaves used to wrap zongzi are immersed in boiling water until they become soft and flexible enough to wrap the product (Lin et al. 2019). In Mexico, most leaves used Lin et al. (2019) to wrap tamale are roasted to soften them and to be able to References insert the dough (Lascurain et al. 2017). In Africa, banana leaves are commonly toasted to make them smooth, supple and easy to use (Boko et al. 1997; Mensah et al. 2012; Onzo et al. 2013). According to Hamid et al. (2017), the prelimi- nary heat treatment would facilitate the release of antimicro- bial or antioxidant compounds from leaves into foods and improve their shelf life and their sensory quality. As part of Rice-based product pre-treatments of leaves, there is also cleaning and washing Food category for hygienic purpose. In Benin, leaves are cleaned by using clean clothes in rain season, while during dry season, they are washed with clean water to get the dust off (Onzo et al. 2013). 6 Effect of packaging leaf on organoleptic quality of food products Food product Several studies reported that volatile compounds of packag- ing leaves infuse the food which gives the product a distinc- Zongzi tive aroma, taste, and color (Boko et al. 1997; Lascurain et al. 2017; Mensah et al. 2012; Ng 2015; Onzo et al. 2016). In Malaysia, wrapping dodol (palm sugar sweet) using palas leaves, makes the dodol more delicious and emits aromatic Continent smell (Zakariah et al. 2019). Plant leaves and bamboo do Asia not only make traditional packaging look more natural, but also affect the flavor and the smell of food (Ardhianto and Hardjana 2016). During tamale processing, in addition to wrapping the dough, some leaves provide a distinctive fla- Country vor according to the plant species (Lascurain et al. 2017). China In Benin, leaves of Thalia geniculata and Daniellia oliveri, particularly known for their aroma are preferably used to wrap lio (maize-based fermented products) (Onzo et al. Botanical families 2013). In China, a recent survey showed that more than 80% of the interviewees preferred to use leaves to wrap zongzi Poaceae because they contribute to zongzi flavor (Lin et al. 2019). The same authors reported that plant species like Nelumbo nucifera, Piper sarmentosum, Indocalamus spp., Musa spp., and Cocos nucifera were preferably used because of their fragrance and flavor. In Malaysia, banana leaves are widely used to wrap foods because of their properties of enhancing food preparations (Mustafa et al. 2012). In many West Afri- Zizania latifolia can countries, Thaumatoccocus daniellii is used to wrapping Table 1  (continued) Plant species foods because it positively influences the color and flavor of the wrapped food (Ayodeji et al. 2016; Onzo et al. 2013). Laboratory analyses have revealed flavor components in some plant species used to wrap foods, confirming the tra- 220 ditional knowledge that leaves contribute to the flavor of the No 13  M. Hounsou et al. Fig. 2  Images on leaf-packag- ing in Benin (Africa). AIcacina tricantha, BTectona grandis, C Musa sapientum, DManihot esculenta, EThalia geniculate, F Gmelina arborea, GStercu- lia tragacantha, HDaniellia oliveri, Iwashing T. geniculate, J blanching I. tricantha, Kakassa (maize based product) wrapped in Isorberlinia doka leaves, L Ikaraewa (legume-based prod- uct) wrapped in Isorberlinia doka leaves Table 2  Pre-treatments of plant leaves Pre-treatments Purpose Examples of Plant species References Cleaning To get rid of dust and other impurities Manihot esculenta, Manihot glazi