Studies On Juice Processing Characteristics Of Bayberry Varieties

Bayberry (Myrica rubra Sieb.etZucc) was a subtropical fruit tree native to China and some otherasian countries, and Zhejiang and Jiangsu province was the main production areas in China. The deepred color and appealing flavor of the mature bayberry make this juicy fruit favored by consumers.Therefore, bayberry juice may be one of the most competitive products in the market. There wereseveral investigations reported on processing technology and shelflife of bayberry. However littleinformation was available on varieties processing characteristics. In this dissertation fourteenbayberry varieties, namely, 'Biqi', 'Dongkui','Wandao', 'Tanmei', 'Wuzi', Dingao', Zaoda','Chida', 'Lizhizhong', 'Zaose', 'Chise', 'Fenghongzhong', 'Baiyangmei', Shuijingyangmei' werecollected from different areas of Zhejiang province. Their juice processing characteristics wereinvestigated mainly on juice rate, stone percentage, sensory quality and chemical composition. Amongthe varieties, BiQi','Dongkui' 'WuZi' at four mature degree; BiQi', 'DongKui', bayberry from differentareas, bayberry with different sizes, bayberry juice with different quality; and bayberry juice withdifferent processing technologies were evaluated too. The main results were described as follows:1. The main nutrients of bayberry juice were determined, and the results showed bayberry juicewas rich in sugar, phenolic acids and mineral elements. The sensory evaluation and preferenceevaluation indicated that 'Wan Dao' were the most suitable for juice processing, and 'Biqi' was thesecond most suitable for juice processing.2. Studies on the characteristics of juice extraction showed that bayberry at 90% maturity was thebest for juice extraction. Fruit weight, juice extraction ratio, stone percentage and pH, total titrable acidity,organic acids,total soluble solids, total and reducing sugar, suger acid ratio, solid acid ratio, compositionof sugars, anthocyanin, total flavonoids, total phenolics, composition of free amino acids, and mineralswere determined in bayberry juice at different maturity. From the results, we can find that fruit weight,juice extraction ratio, pH, total soluble solids, total and reducing sugar, solid acid ratio, individual sugarsand anthocyanin increased along with the maturity degree; titratable acidity and protein decreased alongwith maturity degree.3. Same varieties of bayberry from different areas were compared in this study. Based on the chemicalanalysis, sensory evaluation and preference evaluation, we can concluded that among the "BiQi"bayberry from three city, "Biqi" bayberry from Cixi was the best; as for 'Xianjudongkui' and'Xianshandongkui', the processing characteristics of 'Xianshandongkui' was better; and'Xianshantannmei' was better compared with 'Hangzhoutanmei'.4. The effects of fruit size on the processing characteristic of bayberry juice were studied. As aresult, the bayberry with big size was suitable for juice extraction; However, the processingcharacteristics of the bayberry with small size was better. 5. The impacts of the quality of bayberryfruit on bayberry juice were discussed, and the resultsindicated that the processing characteristics of bayberry juice extracted from bayberry fruit with higherquality was the best. And there were significant differences among different quality bayberry juices inthe content of anthocyanin, total flavonoids, and free amino acids, therefore, we can differentiate thequality of raw material through the examination of the content of anthocyanin, total flavonoids, and freeamino acid composition.