Development of a mixed fruit beverage and pulsed light treatment thereof to obtain a microbially safe and enzymatically stable product

A mixed fruit beverage was formulated according to D-optimal mixture design using apple ber juice(X_(1),45-59%v/v)-an underexplored fruit,carambola juice(X_(2),1-20%v/v),and black table grape juice(X3,35-40%v/v).The crisp overall acceptability(COA)from 16 semi-trained panelists and overall hedonic score(OSH)from consumers were estimated.The best formulation was apple ber:carambola:black table grape juices=59.0:3.5:37.5 v/v with COA and OSH values of 3.23(on a scale of 5)and 7.55(on a scale of 9),respectively.Further,the efficacy of pulsed light(PL)(18-30 W cm^(-2) for 33-167 s;total fluence 600-5000 J cm^(-2))and thermal treatments(90℃ for 1-5 min)were studied on various attributes of the mixed beverage.The beverages processed at 90℃ for 5 min(thermal treatment)and 5000 J cm^(-2)(PL treatment at 30 W cm^(-2) for 167 s)showed no microbial count with a complete enzyme inactivation.The thermally pasteurized sample(90℃/5 min)was more brown(browning index=70.15)than the PL pasteurized beverage(browning index=65.98).Interestingly,the PL pasteurized(5000 J cm^(-2))beverage showed 25%,27%,and 19% more vitamin C,antioxidants,and phenolic compounds,respectively,than the thermally pasteurized(90℃/5 min)beverage.The PL-treated beverage had a greater sensory appeal than the thermally treated beverage.PL-treatment can be an efficient non-thermal pasteurization treatment for ensuring complete microbial and enzymatic inactivation with maximal retention of nutritional and sensory attributes of the blended beverage.

Enzyme hydrolyzed bael fruit liquefaction and its kinetic study

The study aims to explore the mechanism and optimize the process of enzyme hydrolyzed bael fruit(Aegle marmelos)liquefaction using two different enzymes:pectinase and macerozyme r-10(enzyme mixture).A full factorial design was applied for the factors with 0.05–1.5%(w/w)enzyme concentration(EC),30–60℃ temperature,and incubation time of 30–240 min for pectinase and 60–360 min for macerozyme.Quadratic polynomial models were developed,showing R^(2)≥0.94.Multi-objective numeric optimization was followed to maximize the increase in yield,total reducing sugar(TRS),clarity,and minimizing EC,temperature and time.Enzyme-treated juice extracts were acceptable on the sensory scale with overall acceptability>5.Maximum pomace reduction of 58.8%and 78.9%along with rise in mono and disaccharides were observed after treating with pectinase(t=240 min)and macerozyme(t=360 min),respectively at identical 0.775%EC and 45℃ temperature.With the pectinase enzyme,an optimumΔyield of 32.4%was obtained at 0.82%EC,43℃ temperature in 169.4 min.Subsequently,with the macerozyme,an optimumΔyield of 39.6%was attained at 0.96%EC,45.6°C temperature in 245.9 min.Substrate degradation in bael fruit by enzymatic hydrolysis with pectinase(EC=0.01–1.50%,time=2.5–240 min)and macerozyme(EC:0.01–1.50%,time:5–360 min)was studied at their respective optimum temperatures.The modified Michaelis-Menten showed a good fit(R 2>0.98)with the non-linear curve fitting method.Macerozyme treatment showed slower enzyme activity with higher substrate degradation but lower nutrient content compared to the pectinase treatment.