Advanced Materials Research Vols. 941-944

Abstract: Taken black carp fillet as the experimental material, effects of cold-induced on the quality of black carp fillets were studied. Three kinds of cold-induced modes were conducted in this experiment: 10°C constant temperature induction ( mode I ); 2°C/2h ( mode II ); 1°C/1h ( mode III ), at the same time did a comparison with controlled freezing-point storage ( mode IV ). The effect of cold-induced on pH, liquid loss, K value, activity of cathepsin B, free amino acid and proteolysis were compared. Results showed that: the pH value in fillets declined mildly at the storage, the drip loss value and K-value of fillets increased gradually as storage time increased. The K-value of fillets stored at mode I and II increased sharply, while relatively little change was observed in mode III and IV. Cathepsin B activities increased little bit at the storage. The cathepsin B activities of mode III was highest at 11.302U•g^-1, when fillets were stored at controlled freezing-point (44h). Mode II was the second at 10.522 U•g^-1. The total free amino acids (FAAs) of all modes increased to some extent. At 44 hours, the increment of total FAAs in mode II and III were 20.19% and 19.49%, which were superior to mode I (12.27%) and IV (12.97%). No significant differences in protein degradation were observed among those cold-induced modes, but it showed proteolysis on the SDS-PAGE.

Abstract: The Xanthoceras sorbifolia shell activated carbon which was prepared by using zinc chloride as activating agent has a strong adsorption performance of cationic adsorbate (methylene blue) 845.275mg/g and anionic adsorbate (iodine) 1584.96mg/g. Specific surface area study showed that: the adsorption isotherms of activated carbonsamples are type I isotherm adsorption, BET specific surface area was 1455.233m²/g. Displayed by pore specific surface analyzer's measurement results that the pore radius ratio of activated carbon in the range of 3.2-3.4Å is the largest. This proves that these holes are mainly micropores. Meanwhile, the conclusions obtained by the SEM further proof.

Abstract: The microwave pretreatment of pineapple peel for ethanol production was optimized by RSM (Response surface methodology). Three variables, which were studied, were peel to water ratio (100-160 g/L), microwave power (90-900 watt) and time (5-20 min). The optimal condition for reducing sugar production was 132 g/L peel to water ratio, 90 watt for 12 min that provide the 10.4 g/L of highest content. For total sugar production was 160 g/L ratio, 90 watt for 20 min that gave the optimum content of 579.9 g/L. This microwave pretreatment without a reagent could achieve the satisfied sugar content for ethanol fermentation that led to save time and energy consumption.

Abstract: Alpha-amylase is a potentially useful enzyme for the pretreatment and pre-hydrolysis (clarification) of pineapple peel. The clarified products contain sufficient glucose content for ethanol fermentation. The influences of quantity of the peel to water (10-16 %w: weight of peel to weight of water), alpha-amylase amount (100-240 U/g: U of amylase to g of peel), pH value (5.5-7.0), temperature (70-100^oC) and time (60-240 min) were investigated by RSM (Response surface methodology). To obtain 31.8 g/L of the highest glucose concentration, the clarification is to be performed by 16 %w peel to water, 188 U amylase/g, 5.5 pH at 70^oC for 240 min.

Abstract: Calcium ions released from calcium-alginate hydrogel can promote inflammatory responses when injected subcutaneously in mice. In this study, a novel alginate hybrid hydrogel was prepared using sodium alginate (SA) and Glycyrrhizic acid (GA) design for reduce calcium concentration in the hydrogel. nanoCalcium carbonate was wrapped in an alginate solution and internal gelling was induced by the Ca²⁺ released from CaCO₃ by adding of GA. As varying of the amounts of GA and CaCO₃ in alginate solution, the gelling time could be controlled within 10 min. Taking advantage of short gelation time and controlled hydrogel shape, GA calcium alginate hydrogel system has great potential for tissue engineering applications.

Abstract: Round scad (Decapterus maruadsi) was hydrolyzed by composite enzymatic hydrolysis to obtain the hydrolysates possessing high antioxidant activity. The optimum conditions of antioxidant hydrolysates preparation by composite enzymatic hydrolysis were investigated. The results demonstrated that superior antioxidant activities (low IC₅₀ values of radical scavenging activity and high reducing power) were obtained at an enzyme (a mixture of neutral protease and trypsin, 1:1 w/w) to substrate ratio of 0.3%, an incubation time of 5 h and an incubation temperature of 50 °C. Under the conditions, the recovery ratio of protein was 75.24% and the degree of hydrolysis was 25.86%

Abstract: Here, we describe a new method for the separation of trehalose after its enzymatic production. Compound mutagenesis of the Angel strain of Saccharomyces cerevisiae using ultraviolet irradiation and N-ethyl-N’-nitro-N-nitrosoguanidine resulted in three strains with high levels of maltose consumption, as determined by measurement of the residual maltose content of the culture medium. After 48 h of cultivation, the amount of residual maltose in the non-fermentation medium was 12.63%, a seven-fold reduction compared with that obtained with the original, non-mutated strain. Mutant strain G-4C3 produced trehalose with a purity of up to 96.69%.

Abstract: In order to establish our common economic crabs fatty acid fingerprints, the total lipid and phospholipid fatty acid composition of our common economic crabs were determined and analyzed by GC-MS. The results show that: the highest proportion of Eriocheir sinensis is monounsaturated fatty acid (MUFA), while the highest proportion of the other three crab is polyunsaturated fatty acid (PUFA). The percentage of EPA+DHA in Total fat of four kinds of crab is between 7.58%~36.82% .The ratio of EPA and DHA of three kinds of sea crab is higher than it in Eriocheir sinensis. Through the comparative analysis of the fatty acid composition of the total lipid and the phospholipids, we identified seven characteristic fat acids of the four species of crabs.They are C16:0, C18:1n-9, C18:2n-6, C18:3n-3, C20:5n-3, C22:6n-3,and PUFA(PL). Chemical information of four kinds of crabs in lipid composition can be mastered through fatty acids fingerprints of four kinds of crabs which used seven kinds of characteristic fatty acid as index.

Abstract: Objective and Methods: The effect of water temperature on Mandarin fish during live transportation was studied through testing the respiratory rate, ammonia nitrogen in water, glycogen and lactic acid in flesh and blood biochemical indicators at 20°C, 15°C,10°C and 5°C after transported for 0h, 3h, 10h and 24h. Results: The respiratory rate declined with the decreasing temperature and extending transportation time; the ammonia nitrogen in water increased with the temperature falling and lapse of time; the glycogen dropped as time went by and 24h later it declined with the temperature falling; but lactic presented a completely opposite trend; The cortisol decreased with the temperature declined, and rose first and then fell with the time; AST had a negative correlation with water temperature but GLU had a positive correlation; UREA decreased significantly with the declined temperature between 20°C and 10°C, and the level of it at 5°C was close to at 20°C.Conclutions: All these results revealed that 5°C should be selected for short distance transportation less than 10h and 10-15°C was the best choice for long distance transportation.

Abstract: The article mainly investigated the effect of modified atmosphere packaging (MAP) on quality characters of sturgeon caviar during storage at 0 °C . MAP tested included MAP1 (100%CO₂), MAP2 (70%CO₂+30%N₂), MAP3 (50%CO₂+50%N₂), MAP4 (30%CO₂+70%N₂) and MAP5 (100%N₂). In order to let gas mixture interact with caver samples, the caviar directly exposed to modified atmosphere in MAP groups, and the control group (AIR) is prepackaged in tins and maintained in the air. Color properties, biochemical analyses (the volatile basic nitrogen values (TVB-N), the thiobarbituric acid values (TBA )) of sturgeon caviar were recorded before packaging (day 0) and after 1, 3 and 5 months of storage. The results showed that the MAP treatments in the study may delay the protein deterioration to some extend and MAP4 group exposed a little advantage to L*. but MAP treatments didn’t show an positive effects on the a*, b*and TBA.