Soya Beans

Soya Beans: Nutritional Significance

Protein Content

• Soya beans contain 1-8% Low Biological Value (LBV) protein. However, they are a unique plant source of High Biological Value (HBV) protein, essential for growth and repair.
• They contain all essential amino acids necessary for human nutrition.

Fat Content

• Unlike most vegetables, soya beans contain significant amounts of fat, primarily polyunsaturated fats, beneficial for cell membrane formation and reducing the risk of coronary heart disease (CHD).

Carbohydrate Composition

• Carbohydrate content in soya beans ranges from 3-20%, including dietary fibre which helps prevent bowel disorders. They also provide starch for heat and energy.

Vitamins and Minerals

• Rich in vitamins like vitamin A, which helps maintain healthy membranes, skin, and hair, and is crucial for growth regulation. Soya beans also contain vitamin B6 (pyridoxine) for energy release and folate.

Contribution to the Diet

Dietary Benefits

• Soya beans, as a source of HBV protein, are particularly beneficial for vegetarians and vegans.
• The high fibre content aids in digestion and may help in managing blood sugar levels.

Versatility and Use

• Soya beans can be consumed in various forms like tofu, soy milk, and as an ingredient in numerous vegetarian and vegan dishes.
• They can be a meat substitute, offering a protein-rich alternative for various dietary preferences.

Cost-Effectiveness

• Generally, soya beans and their derivatives are affordable, making them a cost-effective protein source.
• They are widely available in supermarkets and health food stores.

Exam Focus: Questions and Answers

1. What is the nutritional significance of soya beans in a vegetarian diet?

In a vegetarian diet, soya beans are significant due to their high-quality protein content, including all essential amino acids, making them an excellent meat alternative. They also provide polyunsaturated fats, beneficial for heart health, and are a good source of dietary fibre and essential vitamins like vitamin A and B6.

2. How do soya beans contribute to health and diet?

Soya beans contribute to health by providing high biological value protein essential for growth and repair, polyunsaturated fats that reduce the risk of coronary heart disease, and dietary fibre for digestion. They also offer a versatile and cost-effective protein source for various diets, especially vegetarian and vegan.

Types of Soya Products

Tofu

• Description: Tofu is made from curdled soya milk, with the curds pressed into blocks, resembling a soft cheese-like texture. It can be smoked for added flavour.
• Uses: Tofu is a highly versatile ingredient, used in a variety of dishes from stir-fries to desserts. It is prized for its ability to absorb flavours from other ingredients.

Soya Milk

• Description: Produced by soaking soya beans in water, grinding them with the soaking water, then heating, filtering, and often flavouring the mixture. It can be homogenised and pasteurised.
• Uses: Soya milk is an alternative to dairy milk, suitable for vegans and those with lactose intolerance. It is used in beverages, cereals, and cooking.

Soya Yoghurt

• Description: This is a non-dairy yoghurt where bacteria cultures are added to soya milk. The mixture is warmed to 30°C to 40°C and then fermented.
• Uses: Soya yoghurt is a dairy-free alternative, often consumed on its own or used in smoothies, desserts, and as a cooking ingredient.

Other Soya-Based Products

• Quorn: Made from mycoprotein derived from fungi, used as a meat substitute.
• Textured Vegetable Protein (TVP): A protein-rich meat substitute made from soya flour.
• Soya Cheese: A dairy-free cheese alternative made from soya milk.
• Soya Ice Cream: A dairy-free alternative to traditional ice cream, made using soya milk.

Exam Focus: Questions and Answers

Describe the process of making tofu and its uses in the diet.

Tofu is made by curdling soya milk and pressing the curds into blocks, creating a soft, cheese-like texture. It is used in various dishes, from stir-fries to desserts, due to its ability to absorb other flavours.

Explain the nutritional benefits of soya milk.

Soya milk, made from soya beans, is a nutritious dairy alternative rich in proteins and often fortified with vitamins and minerals. It is suitable for vegans and those with lactose intolerance and can be used in beverages, cereals, and cooking.