The effect of pulsed light (PL) on numerous important quality characteristics of pineapple juice was studied and compared with untreated and thermally pasteurised samples. The laboratory scale PL batch system used was operated with each three different voltages (1.8, 2.1, and 2.4 kV) and numbers of pulses (47, 94, and 187). Treatments with 2.4 kV and either 94 or 187 pulses (757/1479 J·cm−2) resulted in a 5-log reduction in aerobic mesophiles and the yeast and mould counts. Peroxidase was more resistant to PL than polyphenol oxidase, whereas the bromelain activity was completely retained in all PL-treated juices. Colour and antioxidant capacity were minimally affected, while vitamin C, genuine pineapple furanones, and phenolic compounds declined. In contrast, thermal pasteurisation was more detrimental to colour, antioxidant capacity, and vitamin C content, but resulted in a superior inactivation of microorganisms and enzymes and retention of phenolic compounds. Principal component analysis (PCA) permitted the differentiation of fresh, thermally pasteurised, and all PL-treated juices. PCA on the basis of the individual juice constituents additionally arranged the latter juices according to the number of pulses and voltage levels applied, particularly promoted by the oxidation of ascorbic to dehydroascorbic acid. In conclusion, PL treatment represents a promising new alternative to conventional thermal preservation techniques, whereby the inactivation of deteriorative enzymes may be further optimised.

Indian gooseberry (Emblica officinalis Gaertn.), also known as amla, is considered as a valuable fruit due to the vast content of polyphenols, tannins, minerals, and other phytochemicals. The antioxidant activity of this fruit is due to the presence of emblicanin A and B, which mainly include glucose, gallic, and ellagic acids (Chinprahast, Siripatrawan, Leerahawong, & Traiananwuttikul, 2013). Besides, it is the most abundant source of vitamin C within the citrus fruit family except Barbados cherry, and depending on the cultivars, it ranges from 480 to 550 mg/100 g of pulp (Hiwale, 2015). The consumption of amla fruit also enhances the bioavailability of dietary iron from staple foods such as cereals and pulses (Gowri, Platel,

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The impact of batch thermal treatment (50-95 C/0-10 min) on various quality attributes of a mixed fruit beverage (pomegranate-amla-muskmelon juice = 57:5:38) was evaluated. The responses include microbial count (aerobic mesophiles [AM], yeast and mold [YM], psychrotrophs [PSY], and lactic acid bacteria [LAB]); enzyme activity (polyphenol oxidase [PPO] and peroxidase [POD]); and bioactive (ascorbic acid [AA], total phenolics [TPC], antioxidants [AOC], anthocyanins [TAC], and flavonoids [TFC]). Weibull model indicated a tailing behavior (β = 0.8) for LAB, while others showed the shouldering behavior (β > 1). YM was the most resistant microbial group. Enzyme inactivation and bioactive degradation were discussed with the nthorder model. POD was more resistant than PPO. The corresponding activation energy (E a ) values for PPO and POD were 61.8 and 65.1 kJ/mol, respectively. Among bioactive compounds, AA was most sensitive toward thermal stress. At 95 C, the 90% inactivation of enzyme activity (t 90 value) was achieved after the total process time (come up + holding + cooling time) of 1.5 + 4.1 + 0.3 min. The corresponding losses (%) for AA, TPC, and AOC, at t 90 condition, were 39, 27, and 34, respectively. Practical applicationsThe study attempts to introduce the expression for calculating the time required for 5-log cycle reduction in resistant microbes (t 5D value) and 90% reduction in enzyme activity (t 90 value) of the sample. The kinetic model based on the cumulative approach of come-up time (t CUT ), holding time (t HOLD ), and cooling time (t COOL ) will undoubtedly help in designing the thermal pasteurization process of this mixed fruit juice and thereby pave the pathway for similar counterparts.

The study aims to formulate a mixed fruit beverage through sensory analysis, and the composition was optimized using a fuzzy logic algorithm. The fuzzy optimization algorithm was developed using a modified Takagi and Sugeno's approach, polynomial mixture modeling, and nonlinear solver engine. The optimized blend consisted of amla juice, pineapple juice, and coconut water in 14.3, 63.0, and 22.7%, respectively. Further, the batch thermal treatment was carried out within 50 to 95 °C for an isothermal holding time of 1 s to 10 min, and pasteurization condition for the beverage was estimated from kinetic modeling. The concept of thermal pulse inactivation due to non‐isothermal heat‐up‐time and cool‐down‐time has been introduced within the process time calculation. From the kinetic study, polyphenoloxidase enzyme appeared to be the most resistant entity towards inactivation among all the natural microbiota and quality deteriorating enzymes. Pasteurization in terms of achieving a 5D reduction of both aerobic mesophilic and yeast‐mold counts was attained over a range of 80 to 95 °C for 10.2 + 1.4 to 3.1 + 2.0 min (1.4 and 2.0 min = heat‐up‐time + cool‐down‐time), respectively. The 90% inactivation of both polyphenoloxidase and peroxidase enzymes was obtained over a range of 90 to 95 °C for 12.8 + 1.7 to 8.4 + 2.0 min, respectively. While obtaining both the microbial and enzyme stability at the isothermal condition of 95 °C for 8.4 min, the corresponding retention in ascorbic acid, total phenolics, and antioxidant capacity were observed as 49.7, 63.0, and 61.4%, respectively.Practical ApplicationIn this work, the formulation of a fruit blend was optimized through an intelligent optimization technique (fuzzy algorithm) applied to the sensory data set. The approach for calculating thermal processing time or pasteurization condition provides a new dimension with better precision. The thermal treatment condition of 95 °C for 10 min can be used for this mixed beverage to achieve both microbial stability (5‐log reduction) and enzyme stability (90% reduction). The presented study can be used as a reference for other similar beverages to achieve a complete process design from basic formulation optimization to thermal (batch‐type) processing conditions.