Study On Mild Processing Technology Of Ready-to-eat Mussel

Mussels (Mytilus sp.), type genus of the family Mytilidae, is a species of bivalve shellfish, has become a major sector of the Shallow Sea shellfish culture of China. As a major marine fishery province, Fujian’s annual output of mussel ranked the forefront of the nation, but the process is relatively simple. In order to adjust the product structure and enhance the product added value, with mussel as raw material, to develop mild processing instant food of mussel, the optimal combination of hurdle factors to storage mussel products and the major spoilage bacteria of mussel ready-to-eat food before and after sterilizatio was studied.And the effect of compound preservatives on storage of mussel was further studied. The main research contents were as follows:1.The main constituent of fresh mussels was analyzed and the results showed that the moisture content was81.39%, protein11.16%, fat1.51%, the ash1.80%. It suggested that mussels was a kind of high protein but low fat content shellfish.2.The optimum technological condition of the deodorization of mussels was analyzed, the results showed that the compound deodorization of jasmine tea and ginger juice gave very goodeffects. The addition of jasmine tea, deodorization temperature, deodorization time, ginger juice content were selected as test factors, the smell, taste, colour as organoleptic evaluation indicator. The optimum process parameters of deodorization of mussels were determined as follows through a four factors and six levels orthogonal experiment:jasmine tea:3%, deodorization temperature:40C, deodorization time:100.0min, ginger:1%.3.A fuzzy comprehensive evaluation model of moderate processing instant mussels food was established by using the fuzzy mathematics comprehensive evaluation method, through the analysis of the results evaluation, the best seasoning process was optimized and verified by experiment. The results showed that, mild processing mussel food optimum seasoning process was:white granulated sugar content was10%, MSG content was2%, salt addition was5%,time was70min. 4.The optimal combination of hurdle factors to storage mussel products was studied by analysis of different water activity instant mussel food texture from three aspects as the hardness, chewiness, elastic, and by single factor experiment of sensory score and total colony as index, the results showed the optimum moisture activity range of mild processing instant mussel food was0.90-0.92. The optimum combination of L-malic acid (X1) addition, temperature sterilization (X2) and sterilization time (X3) of the mild processing instant mussel food was ditermined through a experiment using two rotatable central composite design based on the single factor experiment, the colony (Y) as the index, through optimization of Response Surface Method. The results showed that, the optimum combination of fence factor to store mild processing instant mussel food was:Aw0.90-0.92, L malic acid0.28%(pH:5.20-5.40), sterilization temperature95℃, sterilization time40min.5.the main spoilage bacteria in instant mussels food before and after sterilization were analyzed use the PCR Technology (16SrDNA identification method), the results showed that, before sterilization the major spoilage bacteria in the instant mussels food were Bacillus cereus (Bacillus cereus Frankland), Bacillus thuringiensis (Bacillus Thuringiensis), Acinetobacter (Acinetobacter baumannii), Staphylococcus aureus (Staphylococcus), lactis (Lactococcus); after sterilization the major spoilage bacteria in the instant mussels food were Staphylococcus aureus (Staphylococcus) and lactis (Lactococcus).The results further illustrated that the spoilage bacteria could not be killed completely when the sterilization temperature was95℃and sterilization time was40min.6.Preservation effect of compound preservatives on instant mussels food was studied, preservatives composition of the compound preservative was optimized by orthogonal test based on the single factor experiment. The results showed that, the optimum combination of the compound preservative to the instant mussels food was: addition of Nisin solution was0.5%, lysozyme solution0.6%sodium diacetate solution0.5%. Under these, with the synergistic effect of other hurdle factors, it can make the shelf life of instant mussels food to6months at ordinary temperatures.