Study on quality characteristics of different peanut butter
Peanut, which belongs to the legume family, originated in the tropical and subtropical regions of South America. At present, peanut germplasm banks in China have developed in the area of preservation of peanuts. Peanut oil, peanut protein products, peanut beverage, functional extracts of peanuts and peanut leisure food, which are mainly processed products of peanuts, occupy a certain market . As one of the leisure foods, peanut butter accounts for 37% of the consumption of peanuts in China. It is rich in vegetable protein, vitamins (niacin, vitamin E, etc.) and minerals. It has rich nutrition and unique flavor. It is a good accompaniment and condiment.
At present, the consumption of peanut butter in China has gradually increased, and its processing technology has reached maturity, but the influence of Different Peanut Varieties on the quality of peanut butter is not clear. Therefore, taking peanut butter as the breakthrough point, six peanut varieties in China were collected, and the quality of six peanut butter varieties were analyzed and compared, which laid a foundation for selecting suitable peanut varieties for processing peanut butter and avoided the blind selection of peanut varieties when peanut butter machine was used to produce peanut butter.
The sensory quality analysis of peanut butter of different varieties showed that the sensory quality of peanut butter prepared by different varieties varied in color, aroma and taste. According to the overall score, the sensory quality of peanut butter prepared by variety Huayu 20 was the best, and its overall acceptability score was as high as 8.0. The scores of the other varieties were above 6.0, which were mainly influenced by color and taste.
The hardness and viscosity of peanut butter of different varieties were determined by texture analyzer. The results showed that the hardness and viscosity of peanut butter of different varieties varied greatly, ranging from 87.65 to 153.11 g and 65.74 to 113.37 g, respectively. The hardness and viscosity of peanut butter of different varieties were the highest, while that of Shanhua 9 was the smallest. Some studies have shown that the taste and smearing of sensory score are related to the viscosity determined by physical property meter.
The 18 indexes of peanut butter quality (crude protein, crude fat, crude fiber, moisture, ash, total sugar, oleic acid, linoleic acid, sensory acceptability, peroxide value, acid value, iodine value, centrifugal emulsification rate, L*, C*, H, hardness and viscosity) were further analyzed (Table 6). It can be seen from the table that the hardness and viscosity of peanut butter are positively correlated (r=0.982*). It shows that the hardness of peanut butter increases with the increase of its viscosity, and is significantly correlated with L* value, C* value and H value (r=-0.921*, r=0.996*). It shows that the brighter the peanut butter is, the more brown the color of peanut butter is. The lower the angle saturation. There was a significant negative correlation between oleic acid and linoleic acid (r=-0.885*). The results showed that the content of oleic acid and linoleic acid changed slightly after peanut butter was prepared, and the O/L value remained relatively unchanged. Therefore, peanuts with high oleic acid content tended to have lower linoleic acid content, which was compared with Zhang Jianshu et al.  and Shin et al.  The results are consistent.
By taking ethyl palmitate as the research object, the changes of conductivity and fluorescence intensity of ethanol-water-ethyl palmitate ternary system with different concentration before and after flocculent precipitation at certain temperature and alcohol content were studied. The results showed that the conductivity values before and after precipitation were as follows: supernatant after precipitation > before precipitation > blank. The fluorescence intensity of solution with different alcohol precision changed to: blank group > precipitation supernatant > precipitation. The experimental results show that the organic flocs in liquor are influenced by both temperature and alcohol content, and the formation of organic flocs has a significant effect on liquor quality and characteristics.