| Sargassum horneri is rich in carbohydrates,minerals and proteins,but because of its fishy taste and poor taste,it is rarely eaten as a food alone.Dietary fiber is an important nutrient to regulate the dietary structure of human body.The extraction of dietary fiber from S.horneri can not only combine functional fiber with S.horneri to give it good biological activity,improve it toughness and taste,but also provide a new direction for the utilization of S.horneri resources and improve the comprehensive utilization rate of S.horneri.In this paper,dietary fiber was extracted from S.horneri,and the functional characteristics and structure of dietary fiber and its application in edible film were studied.The main research contents and results are as follows:1.The dietary fiber from S.horneri was extracted by enzyme-chemical method,and the single factor orthogonal experiment was carried out on four factors:enzymatic hydrolysis time,enzymatic hydrolysis temperature,cellulase addition and papain addition.According to the results of single factor and orthogonal experiment,response surface method was used to optimize the extraction conditions of dietary fiber from S.horneri.The optimum extraction conditions of S.horneri dietary fiber were determined as follows:the enzymatic hydrolysis time was 1 h,the enzymatic hydrolysis temperature was 50?,the addition of cellulase was100 U/g,the addition of papain was 5000 U/g,and the extraction rate of dietary fiber was32.30%.2.The functional characteristics of the dietary fiber were studied and its structure was analyzed by Fourier infrared spectrum,ultraviolet spectrum and X-ray diffraction.The experimental results show that the dietary fiber has good water holding capacity,oil holding capacity and cation exchange capacity,which can effectively improve human intestinal health and quality of life.The absorption value of dietary fiber glucose of S.horneri was 20.61mmol/g.After dialysis for 30 minutes,the maximum glucose delay value is 30.70 mmol/g,which can directly absorb glucose and reduce the blood glucose of human body.Dietary fiber of S.horneri had certain scavenging effect on DPPH free radical and ABTS free radical,which indicated that dietary fiber of S.horneri had antioxidant properties and could be used as an antioxidant.The study on the structure of dietary fiber showed that it had obvious absorption peak of sugar ester,no nucleic acid and protein,and belonged to the typical structural characteristics of dietary fiber such as cellulose I type.The results provide a theoretical basis for understanding dietary fiber of S.horneri and subsequent product development.3.In this paper,an edible membrane of dietary fiber from S.horneri was prepared.Based on the film thickness,transparency,oil penetration coefficient,dissolution rate,water vapor penetration coefficient and water drop leakage time as indicators,the effects of the ratio of solid to liquid,glycerin content and thickener content on the performance of the edible film of dietary fiber of S.horneri were investigated.The single factor experiment determined that the best conditions for preparing edible film were solid-liquid ratio 1:30,glycerine content of2%,thickener addition of 3%,thickness of edible film 0.11 mm,transparency of 15.07%,oil penetration coefficient of 4.15 g·mm/m~2·d,dissolution rate lower than 35 s/g,water vapor transmission coefficient of 0.58 g·mm/m~2·d·kPa,the water drop leakage time is 500 min/mm.The edible film of S.horneri dietary fiber was determined by gas phase-mass spectrometry(GC-MS).The results showed that the edible film could be used in direct contact with food as food packaging,and it was rich in flavor substances and contained 69 kinds of compounds.The alcohols and aldehydes play an important role in the formation of the main flavor of the edible film. |
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