预处理对蓝莓NFC果汁品质和风味的影响

Effect of Pretreatment on Quality and Flavor of Blueberry NFC Juice

为研究预处理对蓝莓NFC果汁品质和风味的影响,以新鲜蓝莓为原料,探讨热水漂烫和酶解前处理对蓝莓果汁感官品质、过氧化物酶(POD)活性、多酚氧化酶(PPO)活性、出汁率、可溶性固形物、花色苷含量、挥发性香气成分的影响。结果表明:热水热烫可使蓝莓PPO、POD活性显著降低,蒸汽热烫可在60 s内使POD残余酶活力降至7.10%,80℃热烫2 min对蓝莓褐变酶活性的钝化效果最佳,花色苷损失较少,色泽较好;优选果胶酶和纤维素酶按4∶1酶解处理,出汁率高达(81.8±1.5)%,可溶性固形物相比对照组显著提高1.4°Brix,花色苷提高1.92倍;酶解后的果汁香气成分增加,酯类含量增加20%,其中乙酸乙酯、异戊酸乙酯和邻苯二甲酸二丁酯含量增加,同时增加了乙酸异戊酯和苯甲酸乙酯新成分,起到增香的效果。

In order to study the effect of pretreatment on quality and flavor of blueberry NFC juice,the effects of hot water blanching and enzymatic pretreatment on sensory quality,POD activity,PPO activity,juice yield,soluble solids,anthocyanin content and volatile aroma components of blueberry juice were investigated with fresh blueberry as raw material.The results showed that hot water blanching could significantly reduce PPO and POD activity in blueberries,steam blanching could reduce POD residual enzyme activity to 7.10%within 60 s,and blanching at 80℃for 2 min had the best passivation effect on browning enzyme activity in blueberries,with less anthocyanin loss and better color.When pectinase and cellulase were treated with 4∶1 enzymatic hydrolysis,the juice yield was up to(81.8±1.5)%.Compared with the control group,soluble solids were significantly increased by 1.4°Brix,and anthocyanins were increased by 1.92 times.After enzymatic hydrolysis,the fruit juice aroma composition increased and the ester content increased by 20%,among which the content of ethyl acetate,ethyl isovalerate and dibutyl phthalate increased,and the new components of isoamyl acetate and ethyl benzoate were added.