超高压处理的香蕉汁在贮藏期间的品质变化

Changes in the Quality of Banana Juice Treated with Ultrahigh Pressure

研究超高压处理后的澄清香蕉汁在4℃和25℃贮藏期间微生物和营养品质的变化。研究结果表明,香蕉汁在常温(25℃)下经500 MPa的超高压处理2 min后,果汁中的微生物基本杀灭。超高压工艺处理的香蕉汁在4℃和25℃贮藏1 d后,果汁中有少量的亚致死的微生物恢复活力,但在整个8周的贮藏期间,果汁中菌落总数、霉菌和酵母检出量均小于10 cfu/mL。另外,超高压工艺处理的香蕉汁在4℃和25℃贮藏的8周内,果汁的可溶性固形物含量、pH、可滴定酸均没有显著(P>0.05)的变化,并且总酚和DPPH清力还表现出增加趋势。但褐变度表现出上升,且果汁的透光率也表现出略微下降。贮藏温度对超高压处理后香蕉汁的品质影响差异不显著。

Changes in microorganisms and nutritional quality of clarified banana juice treated by high hy -drostatic pressure （500 Mpa,2 min） during storage at 4℃and 25 ℃were studied.Tht results showed that the microorganisms in the banana juice treated with ultrahigh pressure （500 Mpa） at 25℃were completely inac-tivated.A small amount of sublethal microorganisms revived after storage at 4℃and 25℃for one day,but in the entire 8-week storage period ,the detected aerobic bacteria ,molds and yeast were less than 10 log cfu/mL. In addition,no significant （ P〉0.05） changes in the total soluble solids content ,PH,titratable acidity during storage at 4 ℃ and 25 ℃ for 8 weeks were observed , and the total phenolics and DPPH scavenging rate showed an increasing trend .But browning degree showed a rising trend , and the transmittance of the clarifies banana fruit showed a slight decrease .Overall , storage temperature had no significant affect on the quality of clarifies banana juice treated with ultrahigh hydrostatic pressure .