非浓缩还原苹果汁加工过程中物料感官品质的变化

【目的】研究非浓缩还原(NFC)苹果汁加工过程中引起物料感官品质变化的关键环节,为调控果汁内在品质和延长果汁货架期提供理论依据。【方法】测定NFC苹果汁的加工各加工环节中果汁样品中颜色、浊度、可溶性固形物和可滴定酸的含量以及风味的变化。【结果】榨汁后NFC苹果汁亮度值L和色泽h下降了30.99%(P<0.01)和13.45%(P<0.01),但色度C升高了27.62%(P<0.01);护色使得亮度值L和色泽h升高了6.75%(P<0.01)和10.79%(P<0.01),色泽C降低了18.26%(P<0.01);均质环节使得果汁物料的亮度值L降低了6.76%(P<0.01),色度C升高了14.33%(P<0.01);灭酶、杀菌、超声和均质均使果汁的浊度显著升高8.20%(P<0.01)、4.62%(P<0.01)、3.80%(P<0.05);均质和杀菌环节使得可溶性固形物含量降低1.54%(P<0.05)和2.04%(P<0.01),且整个加工过程中,可滴定酸的含量没有显著变化。护色使果汁物料的NEBI值降低46.73%(P<0.01),灭酶使得NEBI值升高15.5%(P<0.05),均质也因为部分氧气再次混入果汁使NEBI增加。护色、杀菌和灌装使得果汁物料溶氧量显著降低。灭酶和灭菌环节对果汁风味损失较大。【结论】NFC苹果汁加工过程中的各加工环节对果汁理化特性均有影响。

Effects of Processing Technology on the Quality of Not-From-Concentrate Apple Juice

【Objective】 To clarify the key links of sensory quality change of non-concentrated reduction (NFC) apple juice during processing, It provides theoretical basis for regulating the internal quality of fruit juice and extending the shelf life of fruit juice. 【Methods】 Identify the key link that causes the change of material sensory quality, the color, turbidity, soluble solids, titratable acids and flavor changes of juice samples in each processing link of not-from-concentrate apple juice were determined.【Results】 The results showed that the luminance L and color h significantly decreased by 30.99% (P< 0.01) and 13.45% (P< 0.01), but the chroma C was significantly increased by 27.62% (P< 0.01). The brightness value L and color h increased by 6.75% (P< 0.01) and 10.79% (P< 0.01), while the color C decreased by 18.26% (P< 0.01). Homogenization reduced the brightness value L of juice material by 6.76% (P< 0.01) and the chroma C by 14.33% (P< 0.01). The turbidity of fruit juice was significantly increased by 8.20% (P< 0.01), 4.62% (P< 0.01) and 3.80% (P< 0.05) by enzyme inactivating, sterilization, ultrasound and homogenization. Homogenization and bactericidal processes reduced the soluble solids content by 1.54% (P< 0.05) and 2.04% (P< 0.01), and there was no significant change in the content of titratable acids during the whole process. Color protection reduced the NEBI value of juice materials by 46.73% (P< 0.01), inactivating enzyme increased the NEBI value by 15.5% (P< 0.05), and homogenization increased the NEBI value because part of oxygen was mixed into juice again. Color protection, sterilization and filling make the dissolved oxygen of juice material decrease significantly. The GC-IMS results showed that the enzyme deactivating and sterilization process had a great loss of juice flavor.【Conclusion】 Therefore, each processing link in NFC apple juice processing has an effect on the physicochemical properties of juice.