Plant-based foods need to be sustainable, palatable, safe, nutritious, and affordable. Society is moving toward sustainability in all aspects of energy, food or preserving life. Food sustainability is one of the driving factors for human survival. A significant concern in the food value system is feeding of 10 billion population by 2050, which requires significant changes in the value chain for sustainability, minimizing the food waste and leading the world population towards more sustainable plant-based foods.(García-Oliveira et al., 2020). The vision of sustainability is nutrition-rich food with limited resources for all humanity. Sustainable diets are “Foods that are affordable, nutritious, developed with ingredients produced in an environmentally friendly manner, and consumer-preferred” (Miller et al., 2021) Plant-based dairy food is a recent, growing trend that is helping the sustainability challenge. A plant-based diet “Consists of minimally processed fruits, vegetables, whole grain, legumes, nuts, seeds, herbs, and spices and excludes all animal products, including red meat, poultry, fish, eggs, and dairy products” (Ostfeld, 2017).
Huge changes are happening in the food industry as manufacturers are creating novelty plant-based products which are ethical and sustainable. In addition, they’re meeting expectations of taste, convenience and affordability. In this write up we will touch in brief on the importance of various ingredients in the manufacture of plant-based foods and their importance to physicochemical and sensory attributes. The next generation of food requires meeting the expectation of micronutrients composition, bio-availability and nutrient profile.
Protein
Protein is the most distinguishing element due to its functional properties imparted to food products in terms of structuring, texturizing, emulsifying, foaming, moisture holding, and nutritional profile. In general, commercial plant-based protein ingredients come in three main forms: flour concentrates and isolates. Typically, the protein concentration increases as one moves from flours to isolates, but the fraction of native proteins remaining often decreases. One of the major problems in the plant-based food area at present is the lack of consistent ingredients that have the desired functional attributes. In particular, the native structure of the plant proteins is often destroyed during the isolation process, and the individual globular proteins may be aggregated to various extents, which leads to a reduction in their water- solubility. The water-solubility of plant proteins is important for many food applications since it is a prerequisite for good functional performance. The properties of plant protein depend upon the source of origin and are influenced by extraction and processing conditions used to convert them into food ingredients. Major issues with proteins are :
Major issues of Uses of Protein
| Issues | Brief Description of the matter | Measure |
| Off flavours | Many plant proteins have undesirable aromas such as beany, earthy, grassy, musty, and woody | Off flavours need to be remove or masked |
| Mouthfeel | Many plant proteins have unpleasant mouthfeels because they are perceived as astringent or bitter | |
| Solubility | Some plant proteins are soluble in water (albumin), some are soluble in salt solutions (globulin), some are soluble in alcohol solutions (prolamins), and some are soluble in weak alkaline solutions (glutelin’s). In addition, solubility also depends upon whether the same is denatured or aggregated. | During isolation and purification need to control such factors as pH, ionic strength, temperature and solvent conditions. |
| Purity | Plant protein ingredients often contain impurities that alter their functional performances, such as dietary fibres, starches, other proteins, lipids, phenolic compounds, and minerals. | Important to develop protein ingredients that only contain the constituents required to create the desired functionality. |
| Inconsistency | Plant protein ingredients often vary from batch to batch due to changes in their composition, denaturation state, aggregation state, or impurities. | Processing operations to isolate high-quality and consistent plant protein ingredients. |
Carbohydrates
Plant carbohydrates vary greatly in their molecular, physicochemical, and biological properties, which impacts their functional performance in foods. At the molecular level, they may vary in their molar mass (low to high), structure (linear or branched), and charge (anionic, neutral, or cationic). At the physicochemical and functional level, they may vary in terms of their water-solubility (soluble or insoluble), emulsification properties (good or bad), thickening power (low to high), and gelling properties (gelling or non-gelling), and water-holding properties (good or bad).
On the nutritional and physiological level, they vary in terms of their digestibility (fast, slow, or none) and colonic fermentability (fermentable or non-fermentable). The selection of an appropriate carbohydrate source for utilization in plant-based food products is therefore important as it will determine their quality attributes, as well as their nutritional profile.
Lipids
The composition of the fatty acid profile in anima products plays an important role in the functionality that they impart to a product. Generally, the fatty acid is triacylglycerol which is basically three fatty acid molecules covalently attached to a glycerol molecule through ester bonds.
The molecular characteristics of the fatty acids in a triacylglycerol determine the physicochemical and functional properties of lipids. For example, the melting point of lipids tends to increase as the chain length of the fatty acids increases and the degree of unsaturation decreases. For this reason, many animal fats, which contain relatively high levels of long-chain saturated fatty acids, such as those found in milk fat or beef lard, tend to be solid-like at ambient temperature.
The crystallization and melting properties of fats are critical for providing desirable properties to many animal-based foods, such as the spreadability of butter, the foaming of whipped cream, the meltability of cheese, and the texture of ice cream. Consequently, it is often important to mimic the crystallization properties of animal fats using plant-based alternatives.
Plant-based fats contain relatively high levels of unsaturated fatty acids which means that they tend to be fluid at room temperature. These fats can be made to be more solid by reducing their degree of unsaturation using hydrogenation processes, but this is often undesirable because it generates trans- or saturated fatty acids, which have been linked to an increased risk of heart disease.
For this reason, food manufacturers often choose to use natural sources of solid fat, such as coconut oil, because it has a relatively high solid fat content at ambient temperatures and can therefore provide solid or plastic characteristics.
Some of the most common plant-based lipids used in the formulation of commercial plant-based foods include avocado oil, canola oil, cocoa butter, coconut oil, corn oil, safflower oil, sesame oil, soybean oil, and sunflower oil.
Other additives which impact the attributes
| Additive | Key functionality |
| Colours and flavours | These additives are often needed to make plant-based products look and taste like the animal foods they are designed to simulate. While, Salts, sugars, spices and herbs are generally added to plant-based foods to enhance their flavour profiles and more closely imitate those of animal origin. |
| Buffers | Buffering agents, such as phosphates, are used to control the pH of plant-based foods since this influences their physical attributes and shelf-life. |
| Cross-linking agents | Enzymes are used to form covalent cross-links between plant protein molecules, thereby increasing the mechanical strength of the product so it resembles animal-based structures. |
| Preservatives | Tocopherols, carotenoids, spices, and herbs can all be used as natural antioxidants, whereas essential oils, curcumin, and polyphenols can be used as natural antimicrobials |
| Micronutrients | Manufacturers add plant-based food products with micronutrients that might be lacking in a vegetarian or vegan diet, such as vitamin D, w-3 fatty acids, vitamin B12, calcium, iron, or zinc . Plant-based foods may also be fortified with bioactive phytochemicals (nutraceuticals) that may improve human health. |
Key functionalities of ingredients
| Function | Property |
| Solubility | The solubility of proteins and polysaccharides from plant origin insolubility in oil, water, or other solvents plays a vital role in determining the quality attributes of foods. Water-insoluble proteins like zein have been used to create structural features within plant-based meat products such as fibres or particulates. Similarly, water-insoluble polysaccharides like cellulose have been used as fat replacers, texture modifiers or bulking agents in processed foods. In plant-based milk and analogues, it is important to identify and understand any binding interactions that occur between the fat droplets/oil bodies and other ingredients in the surrounding aqueous phase, as this can impact the stability of the overall system. |
| Water Holding capacity | It is important to control the ability of plant-based foods to retain their fluids during storage and food preparation particularly for semi-solid foods like meat, egg and yoghurt as examples to have the character of the original food. To achieve this Biopolymers are often incorporated into plant-based foods. |
| Thickening & Gelling | Plant-based biopolymers (especially polysaccharides) are often used as functional ingredients in fluid or semi-solid plant-based food products to increase the viscosity and gelling characteristics by forming a porous 3D network of biopolymer chains. These are used to improve the textural or mouthfeel attributes. |
| Binders and extenders | Biopolymers are often added to plant-based food products as binders, which are ingredients whose purpose is to hold the product together so it does not collapse while extenders are used to add body to the product. |
| Emulsification | Emulsifiers are ingredients that can adsorb to oil-water interfaces and stabilize droplets. They do this by forming a protective coating around the droplets that provides mechanical rigidity to prevent them from aggregating with each other. Generally, emulsifiers used are Proteins that plant originated (e.g., from pea, fava bean, lentil, legume, and soy), polysaccharides (e.g., modified starch and gum arabic), phospholipids (e.g., from soy or sunflower), and saponins (e.g., from quillaja or tea) . Emulsifiers are generally used and enhance the stability of the oil droplets in emulsified plant-based foods, such as milk analogues, cream analogues, dressings, and sauces. |
| Foaming | Foaming agents are ingredients that can adsorb to air-water interfaces and facilitate the formation and stabilization of gas bubbles. Foaming agents are useful in products such as plant-based whipped creams, ice cream, or egg analogues, which may contain gas bubbles to provide desirable textural and stability characteristics. |
| Melting/crystallization | High-melting plant-based lipids like coconut oil or cocoa butter are used for this purpose. It requires selecting an appropriate lipid source, as well as controlling the cooling rate and temperatures. It plays a major role in determining the texture, stability, and mouthfeel. |
| Gastrointestinal Implication | Plant-based ingredients behave differently during digestion compared to animal-based ingredients. |