Effects of Sugar Infiltration Processes on the Quality of Lactic Acid Fermented Orange Peels Preserved Fruit

The aim of present study was to investigate the effects of sugar infiltration processes on the quality of orange peels preserved fruit, the effects of different sugar infiltration processes including normal pressure sugar infiltration, microwave sugar infiltration, ultrasonic sugar infiltration, vacuum sugar infiltration on the color, total sugar, rehydration rate, texture properties, aroma, sensory evaluation of lactic acid fermented orange peels preserved fruit were compared using the handheld color difference instrument, texture analyzer, and electronic nose instruments. The results indicated that the color of fermented orange peels preserved fruit by ultrasonic sugar infiltration (46.01±0.07) was closest to the fresh fruit (52.69±0.09), while the total sugar content (47.12%) was significantly higher than that of normal pressure sugar infiltration (P<0.05). The rehydration rate of preserved fruit was about 135%, which was significantly lower than that of microwave sugar infiltration (P<0.05). Moreover, the three indicators of hardness, chewiness and adhesiveness of the orange peels preserved fruit prepared by the ultrasonic sugar infiltration process were higher than those made by the normal pressure sugar infiltration, microwave sugar infiltration and vacuum sugar infiltration process (P<0.05) except that there was no significant difference for the cohesiveness in terms of the texture (P>0.05). In terms of aroma, the preserved fruit made of ultrasonic sugar infiltration could better maintain the fragrance of orange peels, the sensory score (81.67 points ) of the orange peels preserved fruit prepared under the condition of the ultrasonic sugar infiltration was significantly higher than that of the orange peels preserved fruit prepared by vacuum sugar infiltration (75.80 points), normal pressure sugar infiltration (71.48 points) and microwave sugar infiltration (49.03 points) (P<0.05). The present results supported that the ultrasonic sugar infiltration processes could help to retain the flavor and nutrition of lactic acid fermented orange peels preserved fruit.