【摘要】 为了探讨超高压处理对荔枝果汁品质的影响,将荔枝(“淮枝”品种)原果汁在100~500MPa压力、10℃温度条件下处理30min后,测定果汁的细菌总数、过氧化物酶(POD)活性及营养成分(还原糖、蛋白质、氨基酸、维生素C)等几项指标的变化。结果表明:随着压力值的上升细菌总数逐渐减少,400MPa压力下达到商业无菌;POD的活性随压力值上升逐渐下降,在最高压力500MPa下活性下降约55%;100~500MPa的压力范围内还原糖含量没有显著变化,氨基酸和蛋白质的含量均随压力上升有所下降,维生素C含量在400MPa以上的压力下出现下降趋势,500MPa压力下约下降20%,远远小于热处理的损失。超高压处理对于荔枝果汁有很好的杀菌效果,能一定程度地钝化其中的食品品质酶,同时能较好地保持荔枝果汁中的天然营养成分,因此对荔枝加工来说是一种很有前景的冷加工技术。更多还原

【Abstract】 In order to study the effect of ultra high pressure(UHP) treatment on the quality of lychee juice, the prepared lychee(Lychee chinensis Sonn. cv. Huaizhi) juice was subjected to UHP treatment(100~500 MPa for 30 min at 10℃). Total number of bacteria, peroxidase(POD) activity and nutritional ingredients(including reducing sugar, protein, amino acid and Vitamin C) content were detected. Results show that total number of bacteria declines with pressure increase and arrived commercial asepsis at 400MPa, increasing pressure results in a higher level of POD inactivation with 55% decline at 500 MPa, reduced sugar content have no obvious change from 100 MPa to 500 MPa, the content of protein and amino acid declined a little with pressure increase, Vitamin C content appeares a decreasing trend over 400 MPa with 20% loss at 500 MPa. These results indicate that UHP treatment on lychee juice has a good bactericidal effect, certain passivation effect on food-quality enzyme and a good retention of nutritional ingredients, so UHP treatment is a potential cold-working technique for lychee processing.更多还原