Development Of Linseed Yoghurt And Study On Its Bioactive Peptides

Flaxseed can be used as oil seeds for industrial and consumption of natural health products,rich in linolenic acid,fatty acids,protein,edible fiber and vitamins and other nutrients.Often used in cardiovascular disease,diabetes prevention and improve antioxidant capacity.Yogurt rich in protein,potassium,calcium and vitamin B.It can enhance immunity,improve intestinal flora balance,promote lactose digestion and regulation of blood sugar.In this study,flaxseed meal and skimmed milk was co-cultured to optimize the production process parameters,to obtain a new type of plant fermented milk;at the same time to study the biological activity of the flax seed yogurt;And its amino acid sequence was determined by liquid chromatography-mass spectrometry(LC-MS),and the possibility of its bioactivity was predicted.In the first part,acidity and curd state were used as indexes to determine the ratio of flaxseed meal and skimmed milk was 4:6,curd state is good,and the acidity was up to standard.Used Acidity and sensory evaluation as evaluation indexes,the fermentation condition of FM was optimized by single factor test.The optimum fermentation conditions of FM were:4%of sugar;6 h of fermentation time;1.0g/L of inoculation amount.In the second part,the activity of linolenic acid yoghurt was compared with yoghourt,and the activity of flaxseed meal yogurt(FM)during fermentation was determined.The antioxidation and antihypertensive activity of FM were significantly better than that of yoghourt,and the hypoglycemic activity was not significantly different.In the fermentation process,the antihypertensive activity gradually increased,antioxidant activity remained unchanged,hypoglycemic activity in the fermentation process activity decreased.IIIIn the third part,the samples of three molecular weight fractions of FM bioactive peptides were separated by ultrafiltration,and their activities were determined.Antioxidant activity and antihypertensive activity of the three components were significantly different and low molecular weight activity was significantly higher than the high molecular weight.In terms of hypoglycemic activity,there was no significant difference between low molecular weight and high molecular weight and low molecular weight and high molecular weight.Protein electrophoresis showed that FM in the 3-10 kDa molecular weight compared to the normal range of more than two bands,which may be the reasons of high activity of FM.In the fourth part,two specific protein bands(F1;F2)on the SDS-PAGE of FM were analyzed by LC-MS after in-gel digestion.Sample F1,a flax-derived structural protein Q5I3E6,was obtained by peptide-matching,and two flax-derived storage proteins 2S conlinin Q8LPD3 and Q8LPD4 were obtained by peptide matching.According to the information of peptide matching and electrophoresis molecular weight analysis,the amino acid sequence of the corresponding peptide of F1 was divided into F1-A and F1-B.The corresponding amino acid sequence of F2 was divided into two groups:F2-A and F2-B.Using PeptieRanker to evaluate the activity of these peptides,the F1-A,one peptide of F2-A(mark as F2-A-1)showed activity potential.F2-B and F2-A-1 have the bioactive regions of ACE inhibitory and antioxidant activities peptides,searched by BIOPEP,which may be the reason that FM has better antihypertensive and antioxidant activity than yogurt.Using linseed meal to develop a new type of FM makes the full use of resources,and has a unique flax aroma,sensory evaluation is good.At the same time as linseed meal contains small molecules of high-quality polyphenols and protein,making FM in the anti-oxidation and lower blood pressure than yogurt.The prediction of activity of peptides specific to FM(3-10 kDa)was carried out,and the basic work was done for the extraction and purification of the peptide.