Seeds and Plant-Based Foods: Nutritional Composition, Preparation, and Processing

Objectives

Discuss the nutritional composition of legumes compared to grains and nuts.
Explain preparation methods of legumes.
Discuss plant based milk processing and labeling.
Illustrate plant based product composition.

Nutritional Breakdown

Comparison of nutrient percentages in nuts, cereals/grains, legumes/beans, and oil crop legume soy:
- CHO (Carbohydrates):
  - Nuts: 15-20%
  - Cereals/Grains: 57-80%
  - Legumes/Beans: 58-64%
  - Oil Crop Legume Soy: 34%
- Fat:
  - Nuts: 45-68%
  - Cereals/Grains: 1-8%
  - Legumes/Beans: 1-5%
  - Oil Crop Legume Soy: 18%
- Protein:
  - Nuts: 14-24%
  - Cereals/Grains: 7-18%
  - Legumes/Beans: 20-25%
  - Oil Crop Legume Soy: 37%

Seeds

Grains/Cereals: Seeds of grasses, high in starch.
Nuts: Seeds of trees, large and high in oil to provide an adequate food supply for slow growth.
Legumes: Seeds of plants in pods, high in protein due to symbiosis with bacteria in their roots that fix nitrogen from the atmosphere.
All serve to feed the future generation of the plant, similar to eggs and milk for animals.

Three Sisters Agriculture

Tepary beans are drought-resistant legumes and are part of the Three Sisters agriculture (beans, squash, and corn).
These crops complement each other:
- Corn provides tall stalks for bean vines to grow on.
- Beans provide nitrogen to the soil and stabilize the corn stalk.
- Squash provides large leaves to shade the ground, retain moisture, and prevent weeds.

Tepary Beans

Brown tepary beans are an ancient superfood of the Sonoran Desert.
Subtle earthy flavor with a nut-like taste and aroma reminiscent of summer rain on the desert.
High in soluble and insoluble fiber and protein, and have a low glycemic index.
21 grams of protein in a 1/2 cup serving.
Most drought-adapted species of bean in the world.
Handed down across generations of the Akimel O’odham (River People, Pima) and the Tohono O’odham (Desert People).

Companion Planting

Old-fashioned way with a 3 sisters garden: corn, pole beans, and squash.
Corn supports the beans, the beans add nitrogen and the squash shades out the weeds.
Planting instructions:
1. Plant the corn after the danger of frost has passed.
2. Plant the pole beans when the corn is 5 inches high.
3. Plant squash seeds one week later.

Seed Additional Nutrients

Outer layers of whole grains, legumes, and nuts contain additional nutrients.
Vitamin E: Antioxidant.
Phenolic compounds: Ringed structure antioxidants that act as the plant's defense mechanism.
Lectins: Proteins that interfere with the absorption of calcium, iron, zinc, and phosphorus.
Enzyme inhibitors: Defensive chemicals found in legumes.
B Vitamins:
- Deficiencies of thiamine (B1) can lead to beri-beri due to polishing grains.
- Deficiencies of niacin (B3) can lead to pellagra due to consuming corn without nixtamalization (process using $CaOH$ ).

Fibers

Insoluble Fibers:
- Not digested and do not absorb fluids.
- Provide bulk to speed passage through the large intestine, decreasing toxin absorption.
- The dietary fiber hypothesis was developed by Denis Burkitt.
Soluble Fibers:
- Not digested but do absorb fluids.
- Moderate blood sugar levels and slow digestion.
- Exhibit prebiotic activity.

Soybean Nutrition

Protein Quality of soy protein concentrate using the PDCAAS (Protein Digestibility Corrected Amino Acid Score) scale is 0.99 (beef protein has a PDCAAS of 0.92).
Complete Protein
Fiber
Magnesium, potassium, phosphorus and iron

Soybean Nutritional Concerns

Phytoestrogens (plant estrogens):
- Soy is rich in isoflavones, which are phytoestrogens.
- Phytoestrogens are plant chemicals capable of exerting estrogen-like effects.
Commonly voiced concerns/myths over isoflavones:
- Increases the risk of breast cancer in women.
- Decreases male hormone levels and/or fertility.
- Interferes with thyroid function, hypothyroidism.

Common Soybean Products

Tofu: Referred to as the cheese of soy milk; soy proteins are precipitated out with coagulants such as calcium salts.
Miso: Fermentation product, paste, of a mold on soybeans.
Soy Sauce: Fermentation product, sauce, of a mold on soybeans, often contains wheat.
Tamari Sauce: Fermented soy sauce which contains no wheat.
Tempeh: Fermented soybean cake, also with mold.

Bean Anatomy

Seed coat: Outside layer protecting the bean.
Hilum: the spot where the seed was attached to the plant.
Endosperm: Provides nutrients to the seed.
Cotyledon: Seed leaves that serve as a source of food for the developing plant.
Epicotyl: Develops into the shoot of the plant (stems and leaves).
Hypocotyl: Develops into the lower part of the stem and the roots.
Radicle: Embryonic root.

Cooking of Legumes

Legumes are the driest and hardest ingredients to cook, requiring water and heat.
Nuts, due to their high oil content, are edible directly out of the shell.
Heat enters faster than water, so the challenge is to get absorption.
Water enters through the hilum.
How to increase absorption in cooking:
- Pre-soak
- Blanch first and then pre-soak
- Add salt at about 1%
- Add baking soda (alkaline) at about 0.5%
Three ingredients that slow absorption: acid, sugar, and calcium (hard water).
Using just enough water helps avoid leaching of water-soluble nutrients.
Hard boiling can damage the beans.

Bean Sprouts/Sprouted Grains

Benefits:
- Enhances flavor
- Improves nutrient content
- Increases digestibility and palatability
Sprouting releases alpha-amylase enzymes that break down starches to sugars.
Studies have shown increases in vitamin A, C, E, fiber, amino acids, and antioxidants.
Some studies have shown improved blood sugar and cholesterol levels in individuals with type 2 diabetes.
Food Safety Concerns:
- Raw sprouts are among the top 10 foods to cause foodborne illness.
- Should not be served to children, the elderly, or immunocompromised individuals.

Processing of Legumes - Milk Alternatives

Plant-based milk processing
Oatly is on the rise due to its mouthfeel being more similar to cow's milk; it is also higher in fat and protein content than almond milk, so it steams and froths well.

Definition of Milk

According to the Code of Federal Regulations (CFR) Title 21, FDA guidelines for food definitions:
- Lacteal secretion obtained from the complete milking of one or more healthy cows.
- Pasteurized or ultrapasteurized.
- Contains not less than 8.25% Milk Solids Non-Fat (MSNF).
- Contains not less than 3.25% milk fat.

Dean Foods’ Bankruptcy

America’s largest milk producer filed for bankruptcy because America is drinking less cow’s milk.
Sales have been declining for the last 4 years.
Milk alternatives topped $18 Billion in 2019.

Processing of Legumes – Meat Analogs

Soy is commonly used in meat analogs.
Meat analog: Imitation meat products made of plants.
Soy is used to make TVP (Texturized Vegetable Protein), which are fibrous porous granules that rehydrate quickly.
TVP can be used as a meat extender.
USDA regulates that <=30% TVP is the maximum allowed in a meat product.

Textured Vegetable Protein

Comes in chunks, slices, strips, or granule forms.

Impossible Burgers

Heme molecule is the key to the Impossible Burger, originally sourced from soybean root nodules (soy leghemoglobin).
Now scaled up to yeast fermentation through GMO yeast.
Number one ingredient after water is soy protein concentrate.

Labeling of Meats in the Courts

Meat labeling laws are in effect in 7 states and were rejected in 10 states.
Missouri was the first state to enact the ‘real meat’ law, which means soy products would need to be labeled ‘protein textured’ (law put on hold due to lawsuits).
Mississippi and Arkansas ban plant-based meat providers from using labels like ‘veggie burger or hot dog’.
These laws define beef, beef patties, hamburgers, etc., as being solely applicable to products derived from the flesh of domesticated bovine.
Meat does not include synthetic product derived from a plant, insect, or other source or product grown in a laboratory from animal cells.
Lawsuits challenging these laws have been filed.