Study On Processing Technology And Quality Of Compressed Biscuits For Preventing Constipation

Traditional compressed biscuit is a kind of high-energy food with small volume and easy to carry,which is mainly made of wheat flour.It can be used as a special food for troops,seamen,geological prospectors and outdoor sports enthusiasts.However,due to its lack of dietary fiber,long-term consumption is easy to cause a series of problems such as abdominal distention,loss of appetite and constipation.Therefore,the development of compressed biscuits with the effect of preventing constipation has attracted increasing attention.This study replaced traditional wheat flour with a mixture of cassava flour,sweet potato flour,oat flour,hawthorn flour with high dietary fiber content,corn flour and millet flour with stomach strengthening and stomach protecting function.Oligofructose named water-soluble dietary fiber,and soybean dietary fiber were added to prevent constipation.In this paper,the effects of microwave curing and extrusion cooking on the physical and chemical properties,nutritional components of mixed powder and dough processing characteristics were studied to determine the most appropriate pre-curing process of mixed powder.And the dosage of soybean dietary fiber,fructose-oligosaccharides and edible oil was optimized.At the same time,the baking technology of compressed biscuits was studied.Finally,the physical and chemical properties,starch digestion properties and prevention of constipation properties of the developed compression biscuit for preventing constipation were studied.The results of the study were as follows:(1)The effects of microwave curing and extrusion cooking on the physical and chemical properties and nutritional indicators of the mixed powder were comparatively studied,and the texture,rheological properties and microstructure of the obtained dough were studied to determine the most suitable pre-curing process for the mixed powder.The results showed that the two pre-curing processes had no significant effect on the water content,crude fiber and ash content of the mixed powder.However,the gelatinization degree of extrusion cooking was 96.0%.The mutual adhesion between starch particles in the dough was enhanced,the peak viscosity was 165.5 BU,which had good briquetting formability.Therefore,extrusion cooking was selected as the pre-ripening method of mixed powder.The optimum process parameters were as follows:feeding speed was 38 Hz,screw speed was 160 r/min,extrusion temperature was160?,and initial water content was 20%.(2)Taking sensory evaluation,water holding capacity and texture characteristics of compressed biscuits as indexes,the formula of compressed biscuits was optimized by combining single factor(soybean dietary fiber,fructose-oligosaccharides,edible oil)and orthogonal test.The optimal formula was as follows:mixed powder dosage 49.7%,soybean dietary fiber dosage 6.2%,fructooligosaccharide dosage 6.4%,edible oil dosage 6.7%,brown sugar dosage 17.1%,peanut dosage 12.2%,expansion agent dosage 1.0%,salt dosage 0.5%,baking soda dosage0.2%.The physical and chemical indexes such as bulk density,acid value,peroxide value and water content of the compressed biscuits made by this formula all meet the requirements of relevant national standards,with good water holding capacity,moderate hardness,no sticky teeth and uniform color.(3)The baking parameters of the developed compressed biscuits were determined by comparing the effects of high temperature and low temperature baking on the texture properties,water retention and oligosaccharides retention of compressed biscuits.The retention rate of oligofructose in low-temperature baking compressed biscuits was 88.76%,which was 9.59 percentage points higher than that in high-temperature baking.The water holding,hardness,adhesion and chewability of compressed biscuits baked at low temperature were significantly higher than those baked at high temperature.Low temperature baking(baking temperature 120?,baking time 1 h)was selected as the ripening process of compressed biscuit green body.(4)The physical and chemical characteristics,nutritional composition,texture characteristics,prevention of constipation properties and starch digestion properties of the developed compressed biscuits and three commercially available compressed biscuits(A,B,C)were compared and analyzed.Compared with the three commercially available compressed biscuits,the developed compressed biscuits had significant differences in water content(3.00±0.06%),ash content(2.44±0.14%)and bulk density(0.91±0.00 g/cm~3).However,there was no significant difference in the acid value(1.97±0.08 mg/g)and peroxide value(0.03±0.01 g/100g)of the lipid.The hardness(103.93±4.35 N)and chewability(10.60±0.06 mj)of the developed compressed biscuits were significantly higher than A and B,but there was no significant difference with C,and both were within the sensory acceptable range;Adhesion(1.97±0.04 m J)was similar to A,but significantly higher than B and C.In terms of cohesiveness and elasticity,there was no significant difference between the developed compressed biscuits and commercial products.The water holding capacity,dietary fiber content,resistant starch content and rapidly digested starch concent of the developed compressed biscuits were 1.91±0.16 g/100g,6.74±0.04%,2.86±0.67%and 31.59±0.34%,respectively,indicating that it had certain constipation prevention and treatment functions and could quickly replenish energy for the human body.The digestibility of starch in vitro was only 34.05%,and the sense of satiety was stronger.