Study On Extraction Of Dietary Fiber From Potato Residue And Its Application In Bread

In recent years,due to the continuous expansion of potato production,the development of potato starch industry chain is becoming more and more stable and perfect.The accelerated development of potato starch industry is also associated with a large number of agricultural by-products-potato residue.Usually,the treatment method of enterprises is landfill,but because of its high moisture content,it is easy to rot and deteriorate,and it also produces a lot of pollution to the surrounding environment.Potato residue is a valuable renewable resource,containing a lot of dietary fiber,pectin and starch and other nutrients,so the rational use of potato residue can not only reduce environmental pollution and resource consumption,but also improve people’s diet health.This topic takes potato residue as the research object and optimizes the extraction method of dietary fiber.Then,the extracted potato residue dietary fiber is added to the bread formula and the bread formula is optimized.Finally,bread is made according to the best formula obtained,and its quality and starch digestibility are measured to predict the shelf life of bread under different packaging forms.The main research contents and results are as follows:(1)Extraction process and optimization of dietary fiber from potato residue.The results of single factor experiment showed that when the extraction rate was the highest,the optimal conditions of four single factors were:solid-liquid ratio 1:20,α-amylase addition amount 250 U/g,enzymolysis time 90 min,enzymolysis temperature 60℃.Orthogonal test was carried out to optimize the extraction method,and the optimal extraction conditions were as follows:the ratio of solid to liquid was 1:15,the amount of enzyme added was 250 U/g,the enzymolysis time was 90 min,and the enzymolysis temperature was 65℃.Under the optimal combination conditions,the verification experiment was carried out,and the extraction rate of dietary fiber reached 33.9%.(2)Study and optimization of potato residue dietary fiber bread formula.The optimal dietary fiber extracted from potato residue was added to the bread formula,and the optimal formula was 100 g bread flour,60 g water,1.5 g salt,16 g sugar,19 g dietary fiber and 11 g butter by single factor experiment and response surface optimization test,based on sensory scores and specific volume.The amount of baking powder added was 1.9g,and the sensory score of bread made with this formula was 90.15 points.In addition,the bread quality was measured,and the results showed that the potato residue dietary fiber bread had better quality than the traditional bread without dietary fiber,and the in vitro starch digestibility was low,and the blood sugar of the body rose slowly after people ate this bread,which was suitable for special people who needed to control the sharp changes in blood sugar.(3)The effect of potato residue dietary fiber bread packaging on shelf life.According to the optimized formula,potato residue dietary fiber bread is made with three different packaging forms:①PE bag;②PE bag+deoxidizer(put a small bag of deoxidizer in each PE bag);③PE bag+nitrogen.The samples were packaged separately,and the storage test was carried out,and the physicochemical and microbial indexes were determined regularly to obtain the shelf life.Then,the shelf life of the bread with the best formula was predicted by rapid shelf life experiment(ASLT method),and the shelf life of the bread with PE bag was 24 days,and that with PE bag+deoxidizer was 29 days.The shelf life of the bread packed with PE bag and nitrogen is 36 days,and the shelf life of the bread in the third packaging form is the longest.