What are the types of protein in food? Classification

Proteins are a heterogeneous group of relationships that we can find in various forms on plates and in food products. Although their basic role is to provide amino acids for the structure of tissues and synthesis of enzymes, even in the kitchen we meet many varieties of proteins with different nutritional and functional properties. It is worth knowing not only their sources, but also how they are processed - from whole products, through isolates and concentrates, to modern alternatives, such as proteins obtained from insects or microalg.

In the classification of protein in food, categories are often distinguished due to the origin (animal vs. vegetable), the degree of processing (entire products vs. isolats and hydrolysates), as well as technological functions (emulsifiers, gelatin, gelling agents). Thanks to this knowledge, it is easier to choose the right source for dietary needs: athletes will reach for quickly digestible whey isolates, vegans will choose pea-rose mixtures, and the food industry will use proteins as emulsion stabilizers.

In this article, we will introduce five main groups of protein in food: animal and plant origin, processed forms in the form of isolate and hydrolyzate, alternative sources and functional classification used in food technology. You will find out what properties determine their use, as well as how to compose a diet to derive maximum benefits.

Animal proteins

Traditional sources of animal proteins are meat (beef, poultry), fish, eggs and dairy products. Their advantage is the completeness of the amino acid profile - they contain all the necessary exogenous amino acids in proportions conducive to the synthesis of body proteins. The digestibility of these proteins reaches 95-99 %, which means that almost the entire portion can be used as a building material.

In diet practice, whey proteins (in sports nutrients) and egg proteins (albumin) are most often used, which are characterized by very high biological value and fast absorption. Dairy products - milk, yogurt, rural cheese - also provide calcium and probiotics. Meat and fish outside of protein bring heme iron and B vitamins, although you should choose leeker pieces and limit Red Meat to several portions a week for cardiovascular health.

Proteins of plant origin

Plant sources are legumes (beans, lentils, chickpeas, soy), cereals (oats, quinoa, buckwheat), nuts and seeds. Their amino acid profile is not always full - most often there is a lack of lysine (in cereals) or methionine (in pods) - but this can be balanced by combining various products (e.g. rice with peas, hummus with pita). After thermal treatment and fermentation, the bioavailability of vegetable proteins increases, and digestive inhibitors (phytate, protease inhibitors) are reduced.

Modern vegan nutrients are based on pea, rice or hemp proteins, which in the form of powder reach 80-90 % of the content of proteins. Just mix them in a drink or smoothie to supplement your diet with exogenous amino acids, especially if we have limited consumption of animal products. Vegetable proteins additionally support the intestinal microflora thanks to fiber and bioactive peptides.

Isolates, concentrates and protein hydrolysates

Processed protein forms are highly concentrated products: concentrates (70-80 % protein), isolates (90 % and more) and hydrolysis (quickly absorbed peptides). Whey or soy isolats are formed in ultrafiltration and fat pulling processes, thanks to which they have a minimum lactose or carbohydrate content. Hydrolyzates, enzymely broken into short amino acid chains, go to the bloodstream fastest of all forms, which makes them the perfect choice in post -workout supplementation.

In products like a full -fledged meal of Smart Meal Białka powder are initially enzymely prepared to maximize the digestibility and use of amino acids. Thanks to this, even people with a sensitive digestive system can benefit from the risk of digestive ailments.

Alternative proteins and modern sources

In the face of growing nutritional needs and pursuit of sustainable development, innovative proteins appear: insects (flour, cricel), microalg (spirulina, chlorella), and fermented proteins (mycoprotein). Insect proteins have over 60 % protein content and a favorable amino acid profile, and microalgs also provide omega-3. Mycoprotein (Ferm product) shows high digestibility and is filling, which supports body weight control.

Although these add -ons still evoke associations with the "new diet", today many companies are introducing bars or snacks based on these proteins. It is worth observing the development of fermentation technologies and plants upcycling that allow you to produce proteins with a low carbon trail and high nutritional value.

Classification of proteins by function in the food industry

In food technology, protein is also divided due to the functional properties: emulsifiers (albumin, soy lipoprotein), gelatin (collagen) and gelling (milk, rice proteins). Emulsifiers stabilize mixtures of oil and water (mayonnaise, sauces), gelatin forms gel (desserts, jellies), and protein hydrocolloids increase viscosity and give a creamy consistency (yogurt, ice cream).

The choice of the right protein depends on the pH, temperature and the presence of other ions and sugars. For example, egg albumin form a foam in confectionery foams, and whey proteins with a neutral pH are best formed by emulsions. Understanding these properties enables the design of products with the desired texture and stability.

Sources

• FAO/WHO - Dietary Protein Quality Evaluation in Human Nutrition
• Harvard T.H. Chan School of Public Health - The Nutrition Source: Protein
• European Food Safety Authority - Scientific Opinion on Protein and Amino Acid Requirents
• Journal of Food Science - "Functional Properties of Food Proteins"
• Journal of the American Oil Chemists' Society - "Emulsifying Properties of Proteins"
• Food Hydrocolloids - "Gelation Properties of Proteins"
• Journal of the International Society of Sports Nutrition - "Plant vs. Animal Protein: Biodigestibility and Health Impacts"

FAQ

Can insect proteins be the future of nutrition?

Proteins obtained from insects have a high content of protein (60-70 %) with a full amino acid profile and a favorable breeding effectiveness rate (low water and feed consumption). Studies show good digestibility and lack of allergens characteristic of soy or nuts, which makes them a promising alternative to traditional protein sources.

How do plant proteins affect the intestinal microflora?

Vegetable products, especially fermented (tempeh, miso) or rich in fiber (beans, lentils), support the development of favorable Lactobacillus and Bifidobacterium strains. Improving the intestinal microflora supports the digestion of proteins and may increase the secretion of proteolytic enzymes, which translates into better use of amino acids.

What is the difference between hydrolyzed proteins from protein isolate in terms of absorption?

Hydrolyzed proteins are enzymely broken into short peptides (2-10 amino acids) and free amino acids, which causes their almost immediate absorption in the small intestine. Isolates are long polypeptide chains with high purity (> 90 %), which require standard digestion, but still have high digestibility and minimal lactose content.

What proteins are most often used as emulsifiers in the food industry?

Egg proteins (albumin), soy proteins (lipoprotein) and whey proteins dominate as emulsifiers. Thanks to the ability to lower surface tension, oil-water emulsions, used in mayonnaise, salad sauces or desserts, effectively stabilize.

Is it worth using proteins from exotic plants, e.g. from hemp?

Hemp protein has a favorable profile of Omega-3 and Omega-6 fatty acids (3: 1 ratio) and fiber supporting intestinal peristalsis. Although the protein content (½ 50 %) is lower than in pea isolates, it also provides phytosterols and antioxidants - that's why it is worth combining them with other sources in cocktails or baking.