Advanced Materials Research Vols. 781-784

Abstract: To identify different varieties of oyster juice, a study was conducted to compare the free amino acids (FAAs) determined by automatic amino-acid analyzer in Southern oyster juice, Pacific oyster juice and Pearl oyster juice. In 18 amino acids, glutamic acids, glycine, alanine were considered to be the main flavor amino acids in oyster juice according to the method of Taste Activity Value (TAV). Serine, glycine, alanine, arginine, threonine and histidine proved to be the characteristic amino acids in three oyster juice with different Brix degrees. The standard characteristic amino acids content model chart was established, and it was worked as a characteristic index to identify different varieties of oyster juice. According to the result calculated by included angle cosine, the similarity between the characteristic amino acids content model chart of Southern oyster juice and that of a bottle of market oyster juice turned to be 0.9693.

Abstract: Soybean-peptide, sugar, citric acid and concentrated orange juice as the raw material, orthogonal design and fuzzy logical sensory evaluation were applied together to obtain the best formulation of the soybean-peptide beverages. A L₉ (3⁴) orthogonal array design (OAD) was adopted to prepare nine soybean-peptide beverages. By using fuzzy logical sensory evaluation, the acceptability of these samples was studied. The results indicated that the ranking of sensory attributes for the beverage as follows: Taste > Color > Odor > Appearance; the order of the influence of the raw materials to the acceptability for the beverage as follows: Concentrated orange juice > Soybean-peptide > Citric acid > Sugar; and the best formulation of the soybean-peptide beverages is 5% Peptide-powder, 8% sugar, 0.05% citric acid and 5% concentrated orange juice.

Abstract: By studying the status of the food safety regulatory, this paper points out the drawbacks of existing researches, that is, lack of operability; Relying on the equilibrium theory of game theory, this paper establishes a practical and effective regulatory game model, gives the models mixed strategy Nash equilibrium solution and a food safety regulatory strategy. Finally, to illustrate the effectiveness and feasibility of the model, an illustrative example is shown.

Abstract: Novel composites consisting of chitosan (Ch), polyvinyl alcohol (PVA), and thyme essential oil (T) were prepared as a new packing materials. The effects of Ch+PVA+T film on quality and shelf life of Channa argus stored under refrigeration were investigated. The control and the treated fish samples were analyzed periodically for chemical (pH, TVB-N), microbiological (total viable count), and sensory characteristics. The results indicate that samples treated remained acceptable up 15 days while the untreated samples up to11 days of storage. The thyme essential oil addition in samples contributes to a slower process of fish spoilage. The preservative effect is greater as the oil concentration is greater.

Abstract: The aim of this research was to establish a probabilistic model to predict the growth probability of B. cereus. The five strains of B.cereus were studied and a logistic regression model was chosen to study the interaction of different temperature (10°C, 15°C,20°C,25°C,30°C,35°C), pH(4.5, 5, 5.5, 6, 6.5, 7, 7.5), A_w( 14 levels from 0.992 to 0.932) on the probability of growth. This paper made a fractional factorial design and the experimental data was divided to two parts: 80% of data was chosen as model data and 20% of data was chosen as validation data . At last comparison was made between the predicted values and observed value by choosing 19 experimental data from the published studies. The results showed the concordance index of model data was 0.991 while the validation data was 0.976, indicating that the data was correctly classified and model had a high predictive ability. Also The performance statistics obtained indicate a reasonable goodness of fit of the model obtained, mainly due to the high values of R²-Nagelkerke (0.954) and χ²=0.0119,P=1 of the HosmerLemeshow statistic. A high predictive accuracy is obtained (89.47%) with test data, showing a good predictive ability. In this paper, the growth/no growth model can quantized the combination of environmental factors for B. cereus. This study can help food manufacturers in making decision on the more reasonable and safer formulations for food products in order to prevent the growth of B.cereus along their shelf-life.

Abstract: A characteristic wavelength for measuring flesh browning of apple was put forward based on FT-NIR spectroscopy. Cluster analysis algorithm based on Euclidean distance was applied to selection of representative samples. The multivariable analysis concluding PLS and MLR were applied to build the regression models and seek the characteristic wavelengths of apple flesh browning. The loading weights from PLS model found the sensitive flesh browning wavelengths. The significance of these wavelengths was by ANOVA, and seven wavelengths (1132, 1411, 1429, 1494, 1580, 1879, and 2151nm) were selected with statistical significance at 95% confidence level. These wavelengths were strongly related with apple flesh browning by MLR models evaluated with high prediction correlation (r=0.937). These suggest the model of apple flesh browning was reliable with good predict ability and can meet the requirement to quick determination of flesh browning of apples.

Abstract: Peach is an edible, sweet, juicy fruit and is widely consumed throughout the world. Peach flavor is a very sweet and delightful fruity flavor which can be used in many products. Therefore, developing a peach flavor is of significant interests. This article deals with developing a fresh peach flavor. According to the odor peach fruit, the notes of peach were identified. Proper chemical ingredients were selected to imitate the odor of peach and to create a peach flavor. A fresh peach flavor formula was obtained. The functions and the odors of raw materials in the peach flavor were discussed. The peach flavor obtained is of fresh harmonious peach odor and is very similar to the odor of natural peach fruit.

Abstract: The beef flavor was selected to carry out toxicological analysis regarding food intake, body weight, organs weight and blood biochemical indexes in mice. The results show that beef flavor could suppress food intake but promote mice weight compared with the control group. Flavor intake has significant effect on the ratio of liver and lung weight to the whole body weight, but it has no difference in the ratio of heart, spleen and kidney weight. Some biochemical indexes about fat metabolism in blood such as the total protein, total bile acid and alkaline phosphatase are respectively 4 g/L, 0.7μmol/L and 23 IU/L more than the control group. These factors and cholesterol, triglyceride, low density lipoprotein, high-density lipoprotein cholesterol in the mice blood all have extremely significant differences (P<0.01) in different conditions. The results suggest that the beef flavor has significant impact on fat metabolism in mice.

Abstract: The purpose of this study was to evaluate the impact of different concentrations of tea polyphenols (A1: 0.1%(w/v), A2: 0.5%, A3: 1%), lysozyme (B1: 0.01%, B2: 0.05%, B3: 0.08%) and chitosan (C1: 0.5%, C2: 1%, C3: 2%, C4: 3%) on the quality of pomfret during the storage in order to improve the quality of pomfret fresh preservation. The sensory evaluation, aerobic plate count (APC), trimethylamine (TMA), total volatile basis nitrogen (TVB-N), K value and pH value with different treatments were determined. The results showed that the shelf-life of the control group was 4 days under the cold storage, and the effect of fresh preservation was better with the increasing of the concentration of tea polyphenols, especially the APC could be significantly lower under the treatment groups of A2 and A3 than that under the control group from the 2nd day (P<0.05), the shelf-life was increased by 2 to 3 days. The treatments of B1 and B2 could restrain the increasing of gram-positive bacteria and reduced the contain of TVB-N, TMA-N and K value significantly (P<0.05), the shelf-life was increased by 1 to 2 days. The preservation effect of the treatment of C3 was better than those of control group and other groups with chitosan. The APC, TMA-N, TVB-N and K value could be significantly lower than those of the control group from the 2nd day, so the shelf-life was increased by 3 days. All of tea polyphenols and chitosan could improve the quality of aquaculture and prolong the shelf-life of pomfret by restraining the increasing of APC and the enzyme activity. The results will offer theory reference to the preservation of pomfrets and the application of bio-preservative.

Abstract: To meet the needs of consumers desiring for weight-loss food, investigation on phase characteristics of milk protein-konjac glucomannan multicomponent systems with κ-carrageenan was carried out to simulate healthy ice cream product. Methods of rheology, light scattering and microscopy were used to examine the mechanism underlying the transformation of phase behavior. Addition of κ-carrageenan (0%) evidently showed extensive phase separation that casein micelles concentrated into an irregular discrete phase. A high degree of emulsification of spherical micelle droplets occurring in the continuous serum phase prevented bulk phase separation when the κ-carrageenan concentration increased (0.025%, 0.05%). The analysis of rheological characteristics revealed that multicomponent systems with higher κ-carrageenan concentration were more viscous and showed higher thixotropy behavior due to intense interactions between κ-carrageenan and casein micelles. Frequency independence of G and G was also greatly enhanced as concentration of κ-carrageenan increased. Moreover, differences of size distribution evidenced the structure formation of systems in presence of κ-carrageenan. The joint effects of κ-carrageenan helix aggregation and the interaction between casein micelles and κ-carrageenan were contributed to phase behavior transformation.