Study On The Key Technology Of Grass Crap Convenience Products

Utilizing fresh grass carp as the material, effects of technological process, key technology and formula were studied. Effects of drying method and condition, microwave treatment and edible coating on nutrition, color and sensory quality of convenience grass carp food were researched. The main results were summarized as follows:1. Study on optimization of critical processSalting, fried and synthetic formula were the main critical processes. Chose saline content and permeability in this experiment as index, preserved concentration, curing time, solid-to-liquid ratio and acid content as parameter factors, fixed the critical process. The results shows that the optimized composite of curing condition was saline content was8%,1h, solid-to-liquid ratio was1:3, acetic acid addition was2%. Primary factor of NaCl permeability was curing time and secondary factors were saline content, solid-to-liquid ratio and acid content. Saline content was1.7%in conformity with GB. Chose sensory quality as index,the optimum condition was180℃、4min. Study on sensory quality of basic formula, spicy flavor and sweet flavor can obtain the basic formula:Nacl0.5%, monosodium glutamate0.3%, soy sauce0.25%,2.5%ginger, garlic2.5%. Spicy flavor formula was6%, bean paste, pepper0.4%,0.7%pepper, cooking wine7%. Sweet flavor formula was sugar10%,5%vinegar, tomato paste20%.2. Drying method and condition of fish block was testedBy gradient-rising temperature drying process. The best drying methods and conditions can be obtained by determining moisture and sensory evaluation of fish blocks. The best condition was40℃for4hours in first phase and50℃for2hours in the second phase. It can slow down the lipoclasis. The moisture decreases with the increase of drying time. The drying rate was changed with time and finally become a fixed value.3. Edible film coating on reducing oil uptake in deep-fried fish blocksThe objective of this study was the optimization of edible film coating treatment for reducing oil uptake in deep-fried grass carp fish blocks. The effects of different film coating agents (CMC-Na, Arabic gum and sodium alginate), the time point of film coating agent addition, the concentrations of CMC-Na and sodium alginate (added separately) and the ratio of CMC-Na to sodium alginate when added together at1%in total on oil uptake were probed. In comparison with the control (without the addition of any film coating agent), CMC-Na, Arabic gum and sodium alginate were all able to significantly (P<0.05) inhibit oil uptake in deep-fried fish blocks, showing inhibition rates of21.33%,16.97%and9.99%when added at2%level, respectively. Optimum reduction of oil uptake was obtained when the above films were separately used in the coating processing. Oil uptake was best inhibited by combined use of CMC-Na and sodium alginate at a mixing ratio of1:2, which showed an inhibition rate of34.54%at a total addition concentration of1%.4. Effect of microwave treatment on nutritional components of fishThe content of soluble solids, soluble protein and free amino acid rises with the increasing microwave time in the same microwave power. The soluble sugar decreases with the increasing microwave time. The optimum condition that fish, water, materials adding ratio of10:6:1and treat by microwave in3minutes. The product had good sensory quality compared with traditional fish food.5. Established quality standard for new productThe sensory index, physicochemical and microbial quota were tested to prepare quality standard for new convenience spicy grass carp food product. The optimization of sensory index was good chewy texture, golden brown color, no stain, good taste without any smell but fried fish, smooth in texture, shape complexity without impurities. The physicochemical and microbial quota was protein≥25%, fat≤10%, total sugar≤30%, moisture:from60%to65%, ash:from7%to10%, salt (NaCl)<4%, total number of colonies (cfu/g)≤3000, coliform bacteria (MPN/100g)≤30, no pathogens detected. The results showed that all these indexes of product were up to the national standards for food.