Nutrition Evaluation Of Chongqing Perilla Seed And The Effect Of Pre-heat Treatment On The Quality Of Extracted Oil

Perilla seed,a high-quality natural oil crop seed,are rich in oil,protein,mineral elements,vitamin E and other nutrients,having a broad development value and application prospects.Perilla seed oil can be obtained by pressing perilla seeds,with?-linenic acid content up to 65%,which has various physiological functions such as lowering blood fat,protecting liver,and anti-oxidation,is a high-quality health-care edible oil.But the disadvantages of low oil yield rate,poor oxidation stability and poor flavor have limited the application and development of Perilla seed oil.It is shown that the pre-heat treatment treatment of oil crops can improve the nutrition and flavor quality of vegetable oil.Based on the above situation,this article takes Chongqing Pengshui's Perilla Seed Q as the research objects,samples Chongqing Pengshui's White Perilla Seed W and neighboring Guizhou Province(Perilla Seed G)and Sichuan Province(Perilla Seed C)as controls,compare and analyze the nutritional components(including fat,protein,minerals,vitamin E,fatty acids and amino acids)of perilla seeds from different origins;explore the effects of hot air,infrared radiation,and microwave radiation on the oil yield of perilla seed,and physiochemical quality,antioxidant ability,oxidation stability and volatile components of perilla seed oil.Firstly,use the pressing method to make oil,while exploring the oil yield of perilla seeds,determine the acid value,peroxide value,iodine value,saponification value and fatty acid composition of perilla seed oil,and determine whether the perilla seed oil obtained by three preheating treatment methods meet the national standards;Secondly,determine the content of active ingredients(polyphenols,flavonoids,phytosterols,tocopherols),brownness,antioxidant capacity(DPPH^·+scavenging ability,ABTS^·+scavenging ability,total reducing power),oxidation induction time of perilla seed oil,and analyze the correlation between the oxidation stability,antioxidant capacity and the content of active ingredients and brownness through the Person correlation coefficient;Finally,using the HS-SPME-GC/MS method,explore the volatile components changes of perilla seed oil under the best preheating treatment method,also reveale the major substrate factors affecting the volatile components changes.Through the above research,it provides a theoretical basis for improving the quality of perilla seed oil,and provides reference value for broadening the development and application prospects of perilla seed oil.The main findings were as follows:(1)The nutritional results of perilla seeds found that Chongqing Pengshui Perilla Seed Q's vitamin E content(486.23 mg/kg)and alpha-linolenic acid content of fats(65.43%)rank first;The fat content was 54.31%,second only to the Perilla Seed C(55.59%);Protein content(26.96 g/100g)was second only to Perilla Seed G(28.43 g/100g);The?-6:?-3 PUFA of perilla seed oil was about 0.21:1;Amino acid score(70.03),Chemistry score(55.94)and protein nutrition index(18.45)was the highest.(2)The oil yield of perilla seeds and the physicochemical quality of perilla seed oil showed that the three preheating treatment methods can significantly increase the yield of perilla seeds,and the oil yield of infrared radiation of 180?and 20 min was the highest,4.25%higher than the unpreheated treatment sample.The three preheating treatment methods slightly increased the acid value of perilla seed oil,from 0.93 mg/g without preheating treatment to 1.49 mg/g;The peroxide value(0.81?3.47mmol/kg)increased and decreased;The saponification value decreased slightly;The iodine value was between 188.53?204.80 g/100g,indicating that unsaturated fatty acids content are rich;Before and after preheating(hot air,infrared radiation,microwave radiation)perilla seeds,the oil's unsaturated fatty acid content was 90.84%,90.70%?90.85%,90.59%?90.81%,90.69%?90.86%,of which the content of?-linolenic acid was 62.45%,62.29%?62.45%,62.33%?62.44,62.37%?62.46%respectively.All indicators of Perilla Seed Oil met the standards of"LS/T 3254-2017 Perilla Seed Oil".(3)The oxidative stability and antioxidant capacity of perilla seed oil showed that the antioxidant capacity(DPPH^·+scavenging ability,ABTS^·+scavenging ability,total reducing ability)and oxidation induction of perilla seed oil were significantly increased in three preheating methods(P<0.05).Under the condition of 180?infrared radiation preheating treatment for 30 min,the increase was the largest,from 82.90?g V_C/g,0.47 h to 1070.64?g VC/g,1.74 h,which were 12.91 and 3.74 times of the unpreheated sample.And the trend of change was consistent with polyphenols content,flavonoid content,and browness.The correlation shows that the antioxidant capacity of perilla seed oil is extremely significantly positively correlated with the content of polyphenols,flavonoids and brownness.Among them,the antioxidant capacity has the highest correlation with brownness(r=0.977),followed by the content of polyphenols(r=826);Oxidation induction time has a very significant positive correlation with polyphenols,flavonoids,sterol content,and brownness.The oxidation induction time has the highest correlation with flavonoid content(r=0.676),followed by brownness(r=0.626).(4)The results of analysis of the volatile components of perilla seed oil showed that with the prolonged preheating treatment time,the relative content of heterocyclic compounds such as pyrazines and furans gradually increased,while the relative content of aldehydes,alcohols,esters,hydrocarbons and epoxy hydrocarbons gradually decreased.And the higher the temperature,the greater the change in content.The results of the main substrate factors affecting the volatile components of basilla seed oil found that with the extension of preheating treatment time,the soluble sugar content and total amino acids of defat merilla seed meal were decreased,among which the content of serine,cysteine,threonine,arginine and lysine were significantly reduced.