Flaxseed

Flaxseed, also known as caraway seeds, is the seed of the herb flax, as food and medicine has been used for more than 5000 years of history. Flaxseed is rich in nutrients, which contains a large number of unsaturated fatty acids, linseed gum (dietary fiber), linen lignans, flavonoids, proteins, amino acids, minerals, vitamins and other nutrients.

Flaxseed oil made from flaxseed is an important ingredient to supplement the omega-3 fatty acids, selling price is not low, there is the image of health food. But many people do not know, flaxseed includes all the fatty acids of flaxseed oil, but also contains a lot of nutrients thrown away when the oil is extracted. For example, protein, dietary fiber, a variety of B vitamins, calcium, iron, zinc and other minerals.

Physiological functions of linseed gum

1. Lowering blood sugar and lipid activity
Studies on flaxseed gum to improve glucose and lipid metabolism has been reported for a long time.
Au et al. found that the addition of 0.7% flaxseed gum to milk drinks as a substrate can significantly improve the postprandial glucose response in healthy rats.

Kristensen et al. found that flaxseed gum reduced blood cholesterol levels and increased fecal fat secretion in healthy young subjects, but this effect was related to the properties of the food system in which the flaxseed gum is found.Kristensen et al. also found that flaxseed gum suppressed postprandial lipid levels and appetite in young male subjects, but had no effect on subsequent energy intake.

Above on the flaxseed gum on postprandial lipids and glucose improvement effect are based on the health of the subject animals or population to obtain, but flaxseed gum can be in a specific pathophysiological conditions, such as obesity, insulin resistance and diabetes, to play its hypoglycemic and lipids activity is still to be confirmed by further research.

2. Regulation of intestinal flora and weight loss
Flaxseed gum as a water-soluble dietary fiber, is the key to its regulation of intestinal flora and inhibit obesity. The results of previous in vitro experiments have confirmed that flaxseed gum has a high ability to bind bile acids, and induces the production of intestinal short-chain fatty acids, thus showing the potential to reduce intestinal cholesterol absorption.

Recent studies have found that appropriate intake of linseed gum can inhibit the obesity effect of high-fat-fed rats, and its mechanism of action is related to the inhibition of intestinal sclerotium phylum abundance and sclerotium phylum / anaplasma phylum ratio, and to regulate the growth of specific flora such as Clostridium spp.

3. The effect of modification on the nutritional properties of linseed gum
In order to further improve the nutritional properties and application of linseed gum, the study on the moderate degradation of linseed gum is gradually being carried out.

Du Muxiang et al. Fenton oxidation degradation of linseed gum, obtained a low molecular weight linseed gum – Fe (taro) complex, the complex can be based on covalent or ligand binding to form a stable crystal network structure.

The complex can effectively slow release Fe3+ in a non-Fickian diffusion form, thus providing a new idea for flaxseed gum as a carrier for iron and other nutritional supplements and expanding its scope of application.

The research team also used hydrogen peroxide oxidation to obtain flaxseed gum oligosaccharides (flaxseed gum oligosaccha proto rides, FGOS) with a degree of polymerization of 2~6. Compared with flaxseed gum, FGOS was able to further improve its Fe3+ reducing ability, superoxide anion scavenging ability (72.93 %) and inhibition of lipid oxidation (82.76 %).

The results of in vitro proliferation of lactic acid bacteria found that FGOS can also effectively promote the growth of Lactobacillus rhamnosus, Lactobacillus fermentum, Lactobacillus plantarum and Lactobacillus paracasei, and promote the production of short-chain fatty acids.

Linseed gum in food applications

1. Improve the quality of dairy products
Linseed gum can be applied to dairy products, not only to improve the physical and chemical properties of yogurt, but also to increase the nutritional value of the product.

Studies have shown that the addition of linseed gum can increase the adhesion of stirred yogurt, reduce its viscosity and hardness, without affecting its storage stability. Linseed gum can also replace the commercial film agent polyvinyl acetate, while the cheddar cheese ripening process of lactic acid bacteria and mesophilic aerobic bacterial growth, protein hydrolysis, lipolysis and sensory evaluation of no significant impact.

2. Improve the quality of meat products
Linseed gum can be used as a food additive in low-temperature meat products. The addition of linseed gum can improve the thermal stability of meat proteins, myofibrillar proteins and salt-soluble meat proteins and the stability of the gel structure, which is mainly dependent on the electrostatic interactions between linseed gum – meat proteins.

The addition of linseed gum also enhanced the gel reticulation of low-salt minced meat and improved its emulsification stability, thereby ameliorating the quality deterioration caused by low-salt conditions. In addition, the addition of linseed gum and compound starch to frozen pork balls significantly improved the elasticity, water retention and yield of frozen pork balls.

3. Improve the quality of ice cream and jelly products
Linseed gum and other edible gums have good compatibility, can be used for nutritional jelly production. It was found that the addition of linseed gum can improve the gel strength, elasticity and water retention of jelly. On the basis of the theoretical research that flaxseed gum is based on the regulation of intestinal flora and weight loss, Maiyunshi mixed flaxseed gum with carrageenan and xanthan gum to obtain a compounded jelly product with weight loss effect.