Feasibility of a Novel Industrial-Scale Treatment of Green Cold-Pressed Juices by UV-C Light Exposure

Abstract

Abstract:A novel industrial-scale ultraviolet-C (UV-C) light processor from AseptoRay (MGT, Israel) was used to treat a raw cold-pressed green juice blend (GJB) consisting of kale, romaine, celery, apple, and lemon. The effect of UV-C light energies of 0.88 kJ L −1 and 2.93 kJ L −1 on microbial, enzymatic, nutritional, quality, and sensory parameters of the GJB was studied. Using 2.93 kJ L −1 , 3.7 log reduction in aciduric bacteria and 3.9 logs in aerobic colony count were achieved, while lactic acid bacteria, coliforms, yeasts, and moulds were reduced by >3, >2, 2.1, and 2.1 logs, respectively. A minor increase in polyphenoloxidase (PPO) enzyme activity was seen with 0.88 kJ L −1 and a slight change in colour (not visually observed) was detected using 2.93 kJ L −1 . No other significant change in nutritional and quality parameters or enzyme activities was detected. Further, the stability of the GJB was explored. Kale and romaine contributed the most significant source of spoilage enzyme activity, cloud loss, and browning in the GJB. These stability parameters were shown to be affected by pressing temperature and pH. The commercial UV-C treatment process explored in this study is a viable alternative to high pressure processing (HPP) for improved microbial safety of fresh green juice blends.

How do processing technology and formulation influence consumers’ choice of fruit juice?

“…In recent years, there has been a growing interest in the implementation of processes that minimally modify the sensory, nutritional and functional properties of fruit and vegetable juices and beverages (Bevilacqua et al , ). In particular, premium quality juices obtained by cold pressing have been rapidly growing around the world, mainly due to an increase in consumers’ demand for fresh juice (Biancaniello et al , ). Cold pressing uses hydraulic presses and grinders of low rotation speed, which minimises extraction temperature and contact with oxygen and, consequently, the oxidation of nutrients, volatile compounds and the denaturation of enzymes (Koutchma et al , ; Biancaniello et al , ).…”

“…In particular, premium quality juices obtained by cold pressing have been rapidly growing around the world, mainly due to an increase in consumers’ demand for fresh juice (Biancaniello et al , ). Cold pressing uses hydraulic presses and grinders of low rotation speed, which minimises extraction temperature and contact with oxygen and, consequently, the oxidation of nutrients, volatile compounds and the denaturation of enzymes (Koutchma et al , ; Biancaniello et al , ). However, one of the disadvantages of cold‐pressed juices is their short shelf life, in addition to the risk of disease outbreaks and food poisoning (Danyluk et al , ; Koutchma et al , ).…”

Formulation of a Tropical Beverage by Applying Heat Treatment and High Hydrostatic Pressure

“…Although these studies (1)(2)(3) are related to isolated substances from fruits and are conducted in cell culture or animal models, they provide insights into the possible prevention of these chronic diseases. They encourage the consumption of not only fruits and vegetables, but also of derived products such as natural juices (4) and their mixtures (5,6), providing new flavours and possible synergistic effects on the antioxidant capacity of such matrices (7,8).…”

Development of extracts obtained from yerba mate leaves with different industrial processing steps: Antimicrobial capacity, antioxidant properties, and induced damage

“…Multiple beneficial properties to the human health have been linked to maté tea consumption, including antioxidant and antimicrobial properties (Fayad et al, 2020). Moreover, there is a growing interest in manufacturing leafy green-based juices due to their health-promoting and lowcalorie attributes (Biancaniello et al, 2018). Therefore, in this type of product, the use of yerba mate leaves as a plant-based additive has great potential and it also meets the expectations of those adventurous consumers interested in exploring bolder and novel flavors.…”