Effects of different enzymatic maceration treatments on enhancement of anthocyanins and other phenolics in black currant juice.

摘要

Degradation of blackcurrant skin cell wall polysaccharides using enzymes has previously been shown to release a variety of polyphenols. To investigate this further, 10 pectolytic enzyme preparations, applied as pre-press maceration treatments, were compared for use in the production of juice from blackcurrants. The 10 preparations were used at various doses, and degree of blackcurrant maceration, reaction time and temp. were varied to give 250 different treatments. Treatments were compared on the basis of their ability to enhance the total phenols and anthocyanins contents, yield and turbidity of blackcurrant juice. Juice yields were within the range 66.4-78.9% by wet wt. of blackcurrant mash, while turbidity was between 25 and 916 formazan nephelometric units. Total phenols content was 3050-5100 mg/kg wet. wt. of blackcurrant mash, with anthocyanins accounting for between 900 and 2200 mg/kg wet wt. These parameters appeared to be influenced to a greater extent by reaction conditions (dose, reaction temp., duration and degree of maceration) than by enzyme preparation type. Optimal results were obtained when maceration with the enzyme was performed for 30 min at 60degC, after addition of enzyme (0.18% by wet wt. of mash), to blackcurrants that had been subjected to max. maceration. Juices produced under these conditions exhibited a protective effect against in vitro oxidation of human low-density lipoprotein, which varied with the type of enzyme preparation employed, although anthocyanin profile remained the same.