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Previous reports that women with attractive faces are healthier have been\ud widely cited as evidence that sexual selection has shaped human mate\ud preferences. However, evidence for correlations between women’s physical\ud health and facial attractiveness is equivocal. Moreover, positive results on this\ud issue have generally come from studies of self-reported health in small\ud samples. The current study took standardized face photographs of women\ud who completed three different health questionnaires assessing susceptibility\ud to infectious illnesses (N=590). Of these women, 221 also provided a saliva\ud sample that was assayed for immunoglobulin A (a marker of immune\ud function). Analyses showed no significant correlations between rated facial\ud attractiveness and either scores on any of the health questionnaires or\ud salivary immunoglobulin A. Furthermore there was no compelling evidence\ud that objective measures of sexual dimorphism of face shape, averageness of\ud face shape, or facial coloration were correlated with any of our health\ud measures. While other measures of health may yet reveal robust associations\ud with facial appearance, these null results do not support the prominent and\ud influential assumption that women’s facial attractiveness is a cue of young\ud adult women’s susceptibility to infectious illnesses, at least in our study\ud population.

Chestnut kernel is a woody grain with high nutritional value and utilized value, but it is susceptible to Browning. Previous studies have shown that phenol is the substrate of enzymes that lead to browning. In order to investigate the substrates that that leads to browning of peroxidase (POD) and polyphenol oxidase (PPO) of chestnut kernel. The extraction and purification methods and the main substrates of POD and PPO from chestnut kernel were investigated. First, the effects on enzyme activity of different kinds of buffer, temperature, time and pH value were studied; second, the salting out purification of different concentrations and the main substrates of POD and PPO from chestnut were studied. The results were shown that POD enzyme in chestnut could be obtained by extracting with sodium dihydrogen phosphate-dibasic sodium phosphate buffer (pH 6.8) at 4°C for 5 h. PPO enzyme in chestnut could be obtained by extracting with disodium hydrogen phosphate-citric acid buffer (pH 5.4) at 4°C for 5 h. The two enzymes could be purified best by 80% ammonium sulfate, and the activity of POD and PPO enzyme had been enhanced for 60% and 190% respectively. Gallic acid might be the main substrate of POD and PPO in browning of chestnut kernel.

The purpose of this study was to explore the effect of natural and safe compound preservatives on the shelf life of Beijing sausages. In this thesis, Pseudomonas sp was the first dominant bacterium in the Beijing sausages, which was taken as the research object. The total number of bacteria and the sensory score were taken as the evaluation indexes. On the basis of previous studies, Cinnamon, clove and fennel had good antibacterial effect and those were selected as compound preservatives. By using three-factor quadratic universal rotation design experiment and establishing the mathematical model. Then the effect of single factor experiment shown that within the coding range, the bacteriostatic effects of anise, cinnamon and clove were gradually weakened, the effect of interaction experiment shown that there was significant interaction between cinnamon and clove. When the total number of bacteria reached the lowest level, the optimal ratio of the compound preservatives was determined as follows: cinnamon 0.063 g/mL, clove 1.000 g/mL, fennel 0.810 g/mL. According to this formula, 0.1% of compound preservative was added to the meat and compared to the control group, under the same conditions and time of storage, the total number of bacteria was significantly lower. The result shown that The shelf life of sausages could be extended by 9 days by adding 0.1% compound preservatives.