Legumes: A Comprehensive Guide PDF

Legumes FNSC2001 Prof. Cheng Li  Rundown 1. Overview of legumes 2. Importance and benefits of legumes 3. Preparing dried legumes 4. Highlights of specific legumes Which is legume?  Legumes A member of Fabaceae (or Leguminosae) plant family....

Legumes FNSC2001 Prof. Cheng Li  Rundown 1. Overview of legumes 2. Importance and benefits of legumes 3. Preparing dried legumes 4. Highlights of specific legumes Which is legume?  Legumes A member of Fabaceae (or Leguminosae) plant family. The third largest family of flowering plants. >18,000 species of legumes all over the world in different sizes, shapes, colours and textures. Legume Similar flower and fruit structures - 5-petaled irregular flower in bilateral symmetry (butterfly shaped). - The fruit is a pod, with one row of seeds.  A pod Carry multiple and edible seeds. The pod will naturally open and release its seeds when ripe (Dehiscent). The seed contains two prominent food-storing cotyledons (dicot). image: https://www2.palomar.edu/users/warmstrong/ecoph8b.htm  Composition Seed coat Micropyle Cotyledon x2 Embryo Image: https://ib.bioninja.com.au/higher-level/topic-9-plant-biology/untitled-3/seed-structure.html  Nuts Usually a hard outer shell protecting a single seed. Indehiscent: The shell doesn’t open on its own when ripe.  Drupes Pulp on the outside, hard shell on the inside that contains a single seed. (Stone fruits) Pulses? Beans? Peas? A pulse is an edible seed that grows in a pod (NHS, UK). Pulses include all beans, peas and lentils, such as: baked beans red, green, yellow and brown lentils chickpeas (chana or garbanzo beans) garden peas black-eyed peas runner beans broad beans (fava beans) kidney beans, butter beans (lima beans), haricots, cannellini beans, flageolet beans, pinto beans and borlotti beans https://www.nhs.uk/live-well/eat-well/beans-and-pulses-nutrition/ Legumes, Pulses, Beans https://pulses.org/what-are-pulses  Rundown 1. Overview of legumes 2. Importance of legumes 3. Preparing dried legumes 4. Highlights of specific legumes  Nutritional values An inexpensive source of protein, vitamins, minerals, complex carbohydrate and fiber. Also called the poor man’s meat. Low in fat and sodium No cholesterol Low glycemic index A source of prebiotics that feed gut flora to help prevent digestive disease  Green peas Green lima beans Green beans  Which food group? Individuals can count beans and peas as either a vegetable or a protein food. Green peas, green lima beans, & green beans are considered vegetable groups. http://www.choosemyplate.gov/protein-foods In general, the following can be considered as 1 ounce-equivalent from the Protein Foods Group: 1 ounce of meat, poultry or fish, ¼ cup cooked beans, 1 egg, 1 tablespoon of peanut butter, ½ ounce of nuts or seeds http://www.choosemyplate.gov/vegetables-beans-and-peas  Root Nodules Contain symbiotic nitrogen-fixing bacteria, Rhizobium spp., converting free atmospheric nitrogen (N2) into ammonium (NH4 +). Nitrifying bacteria in the soil quickly convert ammonium to nitrite (NO2 -), and then to nitrate (NO3 -). Nitrate is usually absorbed and used by plants.  Legumes in agriculture Tolerant to most types of soils. Tolerant to drought. Self-pollinating. Legumes enrich the soil. Farmers often rotate legumes with crops that deplete soil nitrogen. The “three sisters”. Easy to grow and harvest. Can tolerate most types of soils. Long storage time when dry. image: https://iowaagliteracy.wordpress.com/2016/11/16/celebrating-the-three-sisters-the-story-behind-the-thanksgiving-celebration/  Rundown 1. Overview of legumes 2. Importance of legumes 3. Preparing dried legumes 4. Highlights of specific legumes https://www.nhs.uk/live-well/eat-well/beans-and-pulses-nutrition/  Preparing dried legumes 1. Remove foreign particles. Rinse well. Put the beans in a cooking pot 3 times the volume of cold water. 2. Soak overnight for~10 hours. No soaking for split peas and lentils. 3. Drain the beans. Place them in a pot and add fresh cold water to cover by 1-2 inches. 4. Bring to a boil. Reduce heat and simmer, covered, until tender. Do not boil. Different simmering time is required for different beans. 5. Check texture for doneness. The beans should remain intact, unless a puree or soup is desired. Properly cooked beans should be soft and creamy, not hard or grainy. 6. If you forget soaking, alternative method: Put the beans in a cooking pot 3 times their volume of cold water. Bring to a boil. When water just start to boil, cover tightly and remove from the heat. Let stand 1 hour. Proceed to step 3.  The purpose of soaking Soaking minimise the gases produced by intestinal bacteria when they ferment the indigestible carbohydrates in beans, e.g. raffinose and stachyose. “it was verified that although the domestic preparation of the common bean significantly reduced the contents of raffinose- type oligosaccharides, total reducing and nonreducing sugars and starch, it did not interfere with its nutritive value.” Queiroz et al (2002) J Nutr Sci Vitaminol (Tokyo) 48(4):283-9. doi: 10.3177/jnsv.48.283. https://pubmed.ncbi.nlm.nih.gov/12489819/  Video: You’re Doing It All Wrong - How to Cook Beans https://www.youtube.com/watch?v=jSbXHusX16g  To do or not to do? Use the soaking water or not in cooking? Soft or hard water? When to add flavour, e.g. tomato source? Add salt at the beginning or the end?  Storage Dried beans will keep up to a year stored in airtight containers in a cool dry place. High temperature, high humidity and too long the storage time will lead to difficulty in cooking.  Rundown 1. Overview of legumes 2. Importance of legumes 3. Preparing dried legumes 4. Highlights of specific legumes 4.1 Broad beans/ Windsor beans Cultivated and eaten for several thousands years in the Mediterranean region. Eating or even inhaling the pollen of broad beans can produce favism, which is hemolytic anemia. Favism is caused by an inherited enzyme (G6PD) deficiency. Common in Mediterranean people, but is aggravated by the type of alkaloids found in broad beans. 4.2 Peanuts Origin: South America Spanish explorers brought them to Europe. Trading introduced peanut to Africa. Slave trade returned peanuts to North America. A staple crop of the South America. Best grow in light sandy soils. The whole growing cycle is about 5 months.  Develop underground After pollination, the flower stalk elongates downward, pushing the developing fruits into the soil. Then the fruit matures into a pod. Highly nutritious and versatile https://youtu.be/4iUduCtx7cA  4.3 Soybean Oil: 13%-25% Complete protein. Protein amount: 30%-50% (even higher than lean beef) Grow best in warm temperate climate with moderate amounts of rainfall. Sacred crops of the ancient China. Domesticated in northern China at least 3000 years ago.  “Cinderella” crops Prior to WWII soybeans are relatively obscure. It suddenly become the second most important income earner among all cash crops, outranked only by corns. From a net importer of oilseeds to exporters. Cash income from $42.2 million in 1940 to $2.5 billion in 1966. Shortening, margarine, cooking and salad oils, paints, resins, plastics, soap, livestock, flour, bakery goods, noodles, candies, fertiliser, coatings, emulsifiers, etc…  Edamame Can’t be consumed raw  Soy milk A non-dairy substitute for lactose intolerant people. Also, no saturated fat Need boiling - Lipoxygenase: convert soy fatty acids to odorous compounds (grassy smell). - Trypsin inhibitor: interfere the digestive process.  Tof u The protein in soy milk is precipitated out through the use of coagulants, e.g. calcium chloride, or magnesium chloride, and then pressed into blocks. - soy cheese - yogurt - sour cream - imitation cream - cheese ice cream-like dessert  Fermented products Deactivates the trypsin inhibitors, phytic acid, hemagglutinin and etc in raw soybean. Therefore, nutrients are more available and digestible, e.g. Vitamin K, Vitamin C, iron, magnesium and fiber. Miso Natto Tempeh (Indonesia) https://www.youtube.com/watch?v=OxG_S0Q-bAg Phytoestrogen Protect against hormonal cancers e.g. breast and prostate Lower the risk of heart disease. Reduce menopausal symptoms and bone loss (osteoporosis) in older women. Some also fear that it causes breast cancer, thyroid problem and dementia. Still controversial Type of study Ethnicity Hormone responses - Pre- and post- menopausal women - Hormone +ve/-ve breast cancer Type of soy  A variety of applications Animal feeds Soy flour (increase the protein content) e.g. breads, pasta, baked goods, Japanese sticky rice pastes’s coating Vietnamese pancake (soya milk + honey) Thickening sauces Protein supplement  Textured Vegetable Protein (TVP) Spinning the soy protein into long slender porous fibres. Rehydrate rapidly. Can pick up flavours easily from other substances. Meat extenders & imitation meats lower costs reduce fat content; cholesterol-free maintain moisture, and add texture by maintaining cohesiveness. USDA limits the use of TVP to no more than 30% in any products. Omnipork  Any questions? 1. Overview and composition of legumes 2. Importance of legumes 3. Preparing dried legumes 4. Highlights of specific legumes