Effects of electrical pre-treatment and alternative heat treatment applications on orange juice production and storage

Effect of different sterilization methods on the appearance, composition, and flavor of sugarcane juice

Cold-pressed sugarcane juice (SCJ) is a beverage rich in vitamins, carbohydrates, and antioxidants. Various sterilization methods impact fruit juice's appearance, nutrients, and flavor. Hence, this study aims to assess how different sterilization techniques affect the flavor, appearance, and nutritional value of SCJ. Freshly prepared SCJs were subjected to two sterilization methods: pasteurization (referred to as PTG) and autoclaving (referred to as HTHP). The pasteurization process was carried out at 63°C for 30 min, whereas the HTHP process was applied at 115°C for 30 min. The appearances, Brix value, colors, sugar, organic acid content, and aromatic compounds were determined. The Brix and pH values of the juice show little variation across different heat treatments. The color index of PTG was similar to that of the control group, whereas the L* value of HTHP increased about 21%, resulting in a significant color change. The glucose and fructose contents of HTHP were 7.03 and 5.41 mg/mL, which were much higher than those of PTG (3.26 and 2.33 mg/mL) and control group (3.33 and 2.48 mg/mL). A total of 77 aromatic compounds were identified in the SCJ after various heat treatments. Among them, pentanoic acid, octanal, and β-damascenone were the most abundant substances contributing to the overall flavor in the control group, PTG, and HTHP. Pasteurization preserved the original flavor of the juice, whereas autoclaving triggered the Maillard reaction, forming pyrazine and furan-like compounds that altered the SCJ's flavor. In conclusion, pasteurization retained SCJ's original characteristics, whereas HTHP induces changes in nutrition and imparts a distinct flavor.

Effects and impacts of technical processing units on the nutrients and functional components of fruit and vegetable juice

Fruit and vegetable juice (FVJ) has become a favorite beverage for all age groups because of its excellent sensory and nutritional qualities. FVJ has a series of health benefits such as antioxidant, anti-obesity, anti-inflammatory, anti-microbial and anti-cancer. Except for raw materials selection, processing technology and packaging and storage also play a vital role in the nutrition and functional components of FVJ. This review systematically reviews the important research results on the relationship between FVJ processing and its nutrition and function in the past 10 years. Based on the brief elucidation of the nutrition and health benefits of FVJ and the unit operation involved in the production process, the influence of a series of key technology units, including pretreatment, clarification, homogenization, concentration, sterilization, drying, fermentation and packaging and storage, on the nutritional function of FVJ was systematically expounded. This contribution provides an update on the impacts of technical processing units on the nutrients and functional components of FVJ and new perspectives for future studies.

How to comprehensively improve juice quality: a review of the impacts of sterilization technology on the overall quality of fruit and vegetable juices in 2010-2021, an updated overview and current issues

Fruit and vegetable juices (FVJ) are rich in nutrients, so they easily breed bacteria, which cause microbial pollution and rapid deterioration of their quality and safety. Sterilization is an important operation in FVJ processing. However, regardless of whether thermal sterilization or non-thermal sterilization is used, the effect and its impact on the overall quality of FVJ are strongly dependent on the processing parameters, microbial species, and FVJ matrix. Therefore, for different types of FVJ, an understanding of the impacts that different sterilization technologies have on the overall quality of the juice is important in designing and optimizing technical parameters to produce value-added products. This article provides an overview of the application of thermal and non-thermal technique in the field of FVJ processing over the past 10 years. The operating principle and effects of various technologies on the inactivation of microorganisms and enzymes, nutritional and functional characteristics, physicochemical properties, and sensory quality of a wide range of FVJ are comprehensively discussed. The application of different combinations of hurdle technology in the field of FVJ sterilization processing are also discussed in detail. Additionally, the advantages, limitations, and current application prospects of different sterilization technologies are summarized.

Retention and stability of bioactive compounds in functional peach beverage using pasteurization, microwave and ultrasound technologies

The peach functional beverages pasteurized for 10 min at 90 °C, microwaved for 1.5 min at 850 W of power and sonicated for 90 min at 20 kHz of frequency were selected to keep in storage for up to 30 days in refrigerator to examine the changes happened to their physicochemical characteristics and functional components. It was observed that the pH and the cloud values of all processed juice samples reduces with the storage time, whereas, the total soluble solids almost remain consistent particularly in microwave and ultrasound treated samples. While storage period causes the decrement in total phenolic content (TPC) and total flavonoid content of treated beverage samples, but ultrasound processing showed greater retention of TPC value up to 5.7% more than other techniques during storage. The similar trend was observed for antioxidant activity where the ultrasound treatment showed improved free radicals (2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) scavenging activities except ferric ion reducing antioxidant power after 30 days of storage.

Storage effects on the quality quartet of orange juice submitted to moderate thermosonication: Predictive modeling and odor fingerprinting approach

The effects of moderate thermosonication (MTS) on the quality quartet: physico-chemical, microbial, nutritional and sensory qualities of orange juice (OJ) inoculated with Alicyclobacillus acidoterrestris (AAT) were studied during 24 days of storage at ambient and refrigerated temperatures. The bioactive compounds and antioxidant activity of OJ decreased with storage, while the pectin methyl esterase (PME) increased. Nonetheless, noticeable changes were observed from the 12th day of storage. There was no obvious (p > 0.05) variation in pH and total soluble solids. To determine the nutritional and microbial quality characteristics of OJ during storage, non-linear kinetic curves were successfully fitted with least square fitting polynomial and four-parameter log-logistic distribution models. The E-nose sensors succeeded in discriminating between the aroma of non-treated and treated OJ based on linear discriminant analysis (LDA). Furthermore, terpenes, alcohol and partially aromatic compounds were the main spoilage indicators of OJ during storage based on E-nose analysis and confirmed by HS-SPME-GC/MS analysis. Thus, MTS significantly extended the shelf life of the quality quartet of natural OJ at 4 °C. E-nose-GC/MS fusion offered odor fingerprints to AAT microorganisms that can be used as spoilage index without using traditional food analysis techniques. The proposed approach can be used as an alternative tool for rapid detection of spoilage microorganisms in OJ.

Changes in Physicochemical and Bioactive Profile of Garlic Pulp by High Voltage Electric Field

Ohmic heating is an unconventional rapid sterilizing technique for complex food fluids. In this study, garlic pulp was ohmic heated at 13.33, 20 and 26.66 V/cm and also in conventional means. The effect of high voltage electric field-induced ohmic heating for increasing the shelf-life and maintaining the quality of garlic pulp was investigated. The physicochemical properties like pH and colour were determined and microbial growth study was carried out for both the ohmic heated and conventionally heated garlic pulp throughout the storage period. During storage, the physiochemical changes were at a rapid rate in conventionally heated garlic pulp when compared with the ohmic heated pulp. Garlic pulp ohmic heated at high voltage gradient (26.66 V/cm) could extend the storage period upto 60 days without adding preservatives. Bioactive compounds were analysed using high performance liquid chromatography and found to have 8.83 µg/mL, 30.28 µg/mL, 9.04 µg/mL of alliin, pyruvic acid and diallyl disulphide content, respectively in garlic pulp ohmic heated at high voltage gradient. Whereas, in conventional heating, alliin, pyruvic acid and diallyl disulphide are found to be 4.71 µg/mL, 22.97 µg/mL, 4.64 µg/mL, respectively