Designing Food Products Using Steam or Wet Heat Processing PDF

DESIGNING FOOD PRODUCTS USING STEAM OR WET HEAT PROCESSING CHAP 4 TS DR MARYANA BT MOHAMAD NOR COURSE OUTLINE: 4.1 Blanching 4.2 Pasteurization / UHT 4.3 Heat sterilization / retort process 4.1 BLANCHING Principle Effect on food ...

DESIGNING FOOD PRODUCTS USING STEAM OR WET HEAT PROCESSING CHAP 4 TS DR MARYANA BT MOHAMAD NOR COURSE OUTLINE: 4.1 Blanching 4.2 Pasteurization / UHT 4.3 Heat sterilization / retort process 4.1 BLANCHING Principle Effect on food  4.2 Pasteurisation/UHT Purpose: Inactivation of bacterial pathogens (target organisms Coxiella burnetti) The two main forms of industrial pasteurisation are: Pasteurization 1. Low Temperature Long Time (LTLT) batch pasteurisation – where the product is held in a and specific temperature range for a long time, e.g. 62º C – 36º C for 30-35 minutes; sterilization 2. high temperature, short time or HTST pasteurisation – where the product is heated to a higher temperature but for a shorter time, e.g. 72 º C for 15 seconds or 63 º C for 30 min for milk, using a plate heater exchange. Definition of pasteurisation: process of heating a food to a specific temperature for a predefined length of time and immediately cooling it after removed from heat. Milk pasteurisation After the milk has been heated it is passed through a regenerator, which brings it into close contact with the cold raw milk pipe. The heat is recycled as the cold raw milk is warmed by close contact with the heated milk. This in turn is cooled. The time, temperature and pasteurisation method used differ according to the product being pasteurised in order to minimise chemical, physical and organoleptic changes (e.g. flavour  TIME AND FACTORS AFFECTING TEMPERATURE : FOOD TYPE; PASTEURISATION VISCOSITY OF PH OF THE PARTICLE EQUIPMENT METHOD THE PRODUCT; PRODUCT; SIZE; USED; USED. High Temperature Short Time (HTST) The HTST pasteurization standard was designed to achieve a five-log reduction, killing 99.999% of the number of viable micro-organisms in milk. This method requires that the milk be held at 161 degrees for 16 seconds. This process, also refereed to as continuous flow pasteurization, requires the milk to be forced through metal pipes that are heated from the outside. Ultraheat treatment or ultrahigh temperature (UHT) UHT is a continuous process and the product is packaged after sterilisation into sterile containers. Typical temperatures and times specified for UHT treatment of milk are 130º C – 150º C for 1-3 seconds. As the product is moving continuously, rather than being stationary, high temperatures can be reached resulting in fewer chemical changes, but having the same sterilising effect. Results of UHT The process results in increased retention of: nutrients - due to short time; colour - as there is no non-enzymic browning; flavour - as there is no non-enzymic browning; texture - since there is no denaturing of proteins. UHT treatment was developed to kill or inactivate all micro- organisms without causing as much damage to the product as sterilisation. Milk may taste cooked and will be slightly brown in colour. ** 4.3 Heat sterilization / retort process This process uses a temperature in excess of 100º C in order to destroy nearly all micro-organisms present in a food. This is important as some micro-organisms can form spores which have the ability to survive at high temperatures. If the correct temperature is not reached there is the possibility that the spores will germinate and grow and food poisoning could result. Some organisms can survive the sterilisation process if not processed for enough time or a high enough temperature, e.g. Clostridium botulinum. The sterilization process in the canned product can be subdivided into three phases. 1. Phase 1 = heating phase. By means of a heating medium (water or steam) the product temperature is increased from ambient to the required sterilization temperature. 2. Phase 2 = holding phase This temperature is maintained for a defined time. 3. Phase 3 = cooling phase The temperature in the can is decreased by introduction of cold water into the autoclave.  Sterilization is a term referring to any process that eliminates or kills all forms of microbial life, including transmissible agents (such as fungi, bacteria, viruses, spore forms, etc.) present on a surface, contained in a fluid, in medication, or in a compound such as biological culture media. Sterilization can be achieved by applying heat, chemicals, irradiation, high pressure, and filtration or combinations thereof. The product is packed in air-tight containers either before or after heat treatment. If packaging follows heating, the containers must be sterilised before use and filled under aseptic conditions. Sterilising enables milk to be kept for 2- 3 weeks unopened, but results in a burnt, caramelised flavour and browning.  Factors affecting sterilisation The application time and temperature depend on the following factors: micro-organisms present; properties of the food product; the products initial temperature; pH of the product; microbe count; the size/volume of the container, e.g. can.  HEAT STERILIZATION: Heat sterilization is the most widely used and reliable method of sterilization, involving destruction of enzymes and other essential cell constituents. PHYSICAL This method of sterilization can be applied only to the THERMO STABLE PRODUCTS, but METHODS it can be used for MOISTURE-SENSITIVE MATERIALS. i) Dry Heat (160-180˚C) Sterilization for thermo stable products ii) moist heat (121-134 ˚C) sterilization is used for moisture- resistant materials. DRY HEAT STERILIZATION It employs higher temperatures in the range of 160-180˚C and requires exposures time up to 2 hours, depending upon the temperature employed. The benefit of dry heat includes good penetrability and non-corrosive nature which makes it applicable for sterilizing glass wares and metal surgical instruments. It is also used for sterilizing non-aqueous thermo stable liquids and thermo stable powders. MOIST HEAT STERILIZATION Moist heat sterilization involves the use of steam in the range of 121-134˚C. Steam under pressure is used to generate high temperature needed for sterilization. Saturated steam acts as an effective sterilizing agent.  GASEOUS METHOD CHEMICAL The chemically reactive gases such as formaldehyde, (methanol, H.CHO) and ethylene STERILIZATION oxide (CH2)2O possess biocidal activity. Ethylene oxide is a colorless, odorless, and flammable gas. METHOD The mechanism of antimicrobial action of the two gases is assumed to be through alkylations of sulphydryl, amino, hydroxyl and carboxyl groups on proteins and amino groups of nucleic acids. PENGETAHUAN ASAS RETORT 1.APA itu RETORT APA PERLU TAHU???? AKTA MAKANAN - Kaedah pengawetan makanan TANPA BAHAN KIMIA i. Menggunakan HABA yang TINGGI (pensterilan) dari julat 111- SIFAT MAKANAN 134℃ diatas tekanan atmosfera. ii. Menggunakan TEKANAN yang TINGGI 15-20psi (1-1.4 bar) TUJUAN - -Masa pensterilan 15-25min PEMPROSESAN Tujuan: untuk membunuh dan merencatkan mikroorganisma TEKNOLOGI yang berbahaya PEMPROSESAN TEKNOLOGI PEMBUNGKUSAN 2. JENIS-JENIS RETORT 1. PRESSURIZED STEAM 2. WATER IMMERSION 3. WATER SPRAY HOME- BASED RETORT ALAT SPESIFIKASI MAKLUMAT Pressure Canner Harga Anggaran di Menggunakan gas seperti pressure Mudah dikendalikan di rumah pasaran RM1000 2500 cooker, material stainless steel Sesuai untuk produk pengetinan dan Terdapat gauge meter yang botol retort menunjukkan bacaan suhu dan Produk yang telah diretort, tidak perlu tekanan serta ada release valve disejukkan ke dalam air sejuk Autoclave (Kecil) Harga Menggunakan stim tekanan tinggi Manual - perlu keluarkan tekanan anggaran di pasaran RM800 RM3800 Manual & auto, elektrik & gas *liter - secara manual Auto-dikawal oleh 24 liter sensor untuk kawalan suhu dan tekanan Tiada proses penyejukan Autoclave (Besar) Harga Jenis Counter Pressure dan bukan Kebanyakkan berfungsi secara auto anggaran di pasaran RM10,000- Tambahan beberapa item seperti Counter pressure berfungsi RM25,000 valve tekanan, saluran air masuk dan mengelakkan pouch pecah Boleh keluar (jenis counter pressure) Antara gunakan botol dan pouch 35liter - 150 liter Penggunakan kuasa elektri 4.5kW hingga 6kW Memerlukan air compressor 3. PRODUK YANG SESUAI DIRETORT Produk berasid rendah (pH >4.6) dan mempunyai activiti air (Aw) sekurang- kurangnya 0.85 Contohnya: Rendang daging, ayam, dendeng, ikan sardin, kari ayam, nasi, daging black pepper, minuman kopi, teh 4. Kepentingan retort Ø Modal sederhana Ø Tidak memerlukan jumlah pekerja yang ramai Ø Homebased Ø Alternatif penyimpanan makanan konvensional Ø Jangka hayat yang panjang untuk tembusi pasaran global (1-2thn) Ø Praktikal dan kian mendapat perhatian pengguna  5. PEMBUNGKUSAN RETORT TERKINI 1.Retort Pouch – Aluminium Pouch (Pillow & Stand) - Biasanya mempunyai 3 lapisan Polyester/ Aluminium/ Polypropylene - Atau 4 lapisan PE/Aluminium/Nylon/PP 2. Transparent Pouch - Biasanya ada 3 lapisan iaitu PE/Nylon/PP - Sesuai utk pes/ nasi himpit/ daging dendeng/kuah kacang 2.Botol kaca - Jenis dan saiz berbeza - Produk keasidan tinggi - Kos dan pengendalian tinggi 3. Spouted pouch – sesuai utk produk cecair - Biasanya terdiri dari 3 lapisan iaitu PET/Nylon/PP jenis RCPP 4. Botol Plastik - PP Polypropylene 5. Tin Aluminium 6. Mangkuk *Tray plastik 6. KELEBIHAN DAN KEKURANGAN RETORT 7. PROSES ASAS SEMASA RETORT FILLING (PENGISISAN) Tempoh masa untuk mengisi produk ke dalam pouch perlu singkat (kurang 2 jam). Suhu makanan selepas masak sesuai untuk pertumbuhan bakteria, sejukkan di persekitaran yang bersih dan terkawal. Isi produk 2/3 daripada pouch, elakkan ruang udara yang banyak Hanya masukkan makanan yang telah dimasak atau separa masak, lap di kawasan sealing jika ada cecair produk Produk boleh terus dimasukkan terus ketika panas jika menggunakan botol. FASA PROSES RETORT (approx.: 60-180 min) 1. COME-UP TIME (CUT) - diambil dari bermulanya proses pemanasan (heating) dari mula hingga mencapai suhu retort yang kita ingini -diambil sepanjang suhu mencecah suhu retort (yang kita aturkan) sehingga tamat. - Ini adalah suhu dan waktu yang kita set di mesin retort 2. Holding Time (cooking stage) - Masa yang diambil sepanjang suhu mencecah suhu retort (yang kita aturkan ) sehingga tamat. - Ini adalah suhu dan waktu yang kita set di mesin retort 3. Come-Down Time (CDT) /Cooling Time - kritikal -Air sejuk dimasukkan untuk merendahkan suhu secara berterusan. - Tempoh masa setelah selesai proses pensterilan hingga sejuk dan selamat untuk dikeluarkan pouch/bag dari mesin KUARANTIN Produk yang telah diretort perlu di kuarantin. Kenapa? Bagi memastikan proses pensterilan telah sempurna. Sekiranya tidak disteril dengan sempurna, pouch akan mengembung, atau pecah  PELABELAN -Selepas tempoh kuarantin, produk boleh dilabel. -Antara perkara yang perlu ada pada label produk adalah: a. Maklumat kandungan (Nyatakan jumlah berat bahan yang digunakan, senaraikan bahan yang paling berat) b. Cara penyediaaan (Kaedah menyediakan produk sebelum dimakan) c. Cara penyimpanan (Sejuk beku, sejuk, suhu bilik) d. Maklumat pengusaha (Nama syarikat, no.hp untuk dihubungi, alamat dll) e. Tarikh luput f. Berat / Isipadu isian ‘Do and Don’t) Plastik ‘pouch’ pecah – i. ‘pouch’ tidak berkualiti ii. perbezaan suhu luar pouch dan suhu dalam semasa proses penyejukan( ‘cooling’ proses yang mendadak) Plastik ‘pouch’ menggelembung i. tindakbalas mikroorganisma ii. Suhu tidak mencapai 121 terutamanya bg makanab berprotein tinggi Bahan yang melibatkan santan –guna santan kotak Produk tenusu- Skimmed milk powder (non –fat milk) Bahan rempah ratus (kayu manis, bunga lwang, cengkih) –kisar supaya tidak merosakkan pembungkus. ‘seafood’- sebaiknya cengkerang kena keluarkan Ikan- isi ikan yang tidak terlalu lembut-mengubah tekstur Rasa, warna dan tekstur makanan berubah??? -3 -5% berubah (bergantung kepada ingredient produk ) Produk beku perlu disteamkan sebelum retort