Fruit Juice Production Using Ultraviolet Pasteurization: A Review

Effects of heat treatment and ultraviolet radiation on physicochemical, microbiological, and bioactive properties of shalgam juice

Herein, we aimed to investigate the physicochemical, bioactive, microbial, and sensory properties of 5 different ultraviolet (UV) treatment conditions, varying in flow rate (1.5-2.5-3.5 L/min), temperature (5-25°C), and UV-intensities (5.1-10.1 mW/cm2), along with heat treatment (HT, 72°C for 20 s), and untreated samples (C) over a storage period of 150 days. At the beginning of storage, the samples exhibited a dry matter content ranging from 2.15% to 2.38%, pH levels ranging from 3.46 to 3.53, and total acidity between 6.35 and 6.51 mg/L. L* values were recorded between 33.09 and 33.50, while ΔC values ranged from 9.13 to 9.24. However, by the end of storage, these values had changed to 2.28-2.43% for dry matter, 3.47-3.49 for pH, 6.22-6.35 mg/L for acidity, 34.94-35.57 for L* values, and 6.95-7.01 for ΔC values. Throughout storage, total mesophilic aerobic bacteria (TMAB), lactic acid bacteria (LAB), and yeast and molds were measured at the highest levels in the C samples when compared to HT and UV-treated samples. At the end of storage, compared to the initial values, TMAB levels in UV-treated samples decreased from 3.29-4.80 log cfu/mL to 3.13-3.92 log cfu/mL. On the other hand, compared to the initial values (3.29-4.01 log cfu/mL), LAB levels decreased by 1.93-2.42 log cfu/mL by the end of storage. Initially, in UV-treated samples, the TPC (total phenolic content) ranged from 398.15 to 403.86 mg GAE/g, DPPH antioxidant activity ranged from 811.52 to 834.89 mg TE/L, and TAC (total anthocyanin content) ranged from 5.58 to 5.74 mg/L. By the end of storage, an increase was observed in all bioactive properties analyzed. Furthermore, UV treatment positively impacted the bioaccessibility of bioactive compounds compared to the HT-treated sample. Overall, this study confirms that UV-C technology can be used as an alternative method for extending the shelf life of shalgam juice while preserving its sensory and bioactive attributes.

Influence of Ultrasonication and UV-C Processing on the Functional Characteristics and Anticarcinogenic Activity of Blackthorn Vinegar

In recent years, consumer trends have been changing toward fresh food products such as fruit juice, vinegar, etc. that are a good source of bioactive components, high nutritional characteristics, and beneficial microorganisms. Blackthorn (Prunus spinosa L.) vinegar (BV) is one of these nutritious foods. The study aims to examine the efficacy of ultraviolet-C (UV-C) light applied by a modified reactor and ultrasonication on bioactive compounds (total phenolic, total flavonoid, ascorbic acid content, and antioxidant activity) of traditionally produced BV. Furthermore, the volatile organic compound (VOC) profile, hydroxymethylfurfural (HMF) content, cytotoxicity properties, and color were assessed. UV-C light and ultrasonication processes enriched most bioactive components, but these methods did not significantly improve ascorbic acid (p > 0.05) compared to pasteurization. Twenty-seven volatile compounds were analyzed in order to determine the VOC profile. As a result, thermal and nonthermal methods were found to affect the profile significantly (p < 0.05). No significant differences were detected in total soluble solids (4.70-4.77), titratable acidity (3.81-3.87), and pH (3.39-3.41) values. The anticarcinogenic activities of UV-C-treated BVs were more significant than others. Nonthermal treatments were generally better than pasteurization in maintaining and enriching the quality of BV. In this study, UV-C light and ultrasonication technology can be used as an alternative to traditional thermal techniques to improve the quality of BV.

Tapping into Palm Sap: Insights into extraction practices, quality profiles, fermentation chemistry, and preservation techniques

The quality profile, extraction yield, and fermentation chemistry of palm sap depend on various factors such as extraction technique, weather conditions, and preservation methods. This review aims to provide a detailed overview of palm sap extraction techniques and the methods for its preservation. The compositional analysis of palm sap, including physical and chemical parameters such as sugar content, acidity, and mineral composition, is discussed thoroughly. The role of microorganisms in fermentation and the effects of various influencing factors are also critically examined. Additionally, this review evaluates different preservation methods, including thermal processes, refrigeration, and electrical techniques, highlighting their effectiveness in extending the shelf life of palm sap. The review further explores the emerging impact of nanotechnology on palm sap preservation, offering insights into the latest industry challenges, developments, and future prospects. By presenting these findings, this review aims to enhance the scientific understanding of palm sap and stimulate additional research and innovation in the field, paving the way for improved production practices and product quality.

Advancements in nonthermal physical field technologies for prefabricated aquatic food: A comprehensive review

Aquatic foods are nutritious, enjoyable, and highly favored by consumers. In recent years, young consumers have shown a preference for prefabricated food due to its convenience, nutritional value, safety, and increasing market share. However, aquatic foods are prone to microbial spoilage due to their high moisture content, protein content, and unsaturated fatty acids. Furthermore, traditional processing methods of aquatic foods can lead to issues such as protein denaturation, lipid peroxidation, and other food safety and nutritional health problems. Therefore, there is a growing interest in exploring new technologies that can achieve a balance between antimicrobial efficiency and food quality. This review examines the mechanisms of cold plasma, high-pressure processing, photodynamic inactivation, pulsed electric field treatment, and ultraviolet irradiation. It also summarizes the research progress in nonthermal physical field technologies and their application combined with other technologies in prefabricated aquatic food. Additionally, the review discusses the current trends and developments in the field of prefabricated aquatic foods. The aim of this paper is to provide a theoretical basis for the development of new technologies and their implementation in the industrial production of prefabricated aquatic food.

UV-C Light: A Promising Preservation Technology for Vegetable-Based Nonsolid Food Products

A variety of bioactive substances present in fruit- and vegetable-processed products have health-promoting properties. The consumption of nutrient-rich plant-based products is essential to address undernutrition and micronutrient deficiencies. Preservation is paramount in manufacturing plant-based nonsolid foods such as juices, purees, and sauces. Thermal processing has been widely used to preserve fruit- and vegetable-based products by reducing enzymatic and microbial activities, thereby ensuring safety and prolonged shelf life. However, the nutritional value of products is compromised due to the deleterious effects of thermal treatments on essential nutrients and bioactive compounds. To prevent the loss of nutrients associated with thermal treatment, alternative technologies are being researched extensively. In studies conducted on nonsolid food, UV-C treatment has been proven to preserve quality and minimize nutrient degradation. This review compiles information on the use of UV-C technology in preserving the nutritional attributes of nonsolid foods derived from fruit and vegetables. The legislation, market potential, consumer acceptance, and limitations of UV-C are reviewed.

Inactivation of Alicyclobacillus acidoterrestris spores, single or composite Escherichia coli and native microbiota in isotonic fruit-flavoured sports drinks processed by UV-C light

Pasteurized sports drinks and other fruit-based beverages are susceptible to deterioration due to thermal processing ineffectiveness to inactivate certain spoilage microorganisms, like Alicyclobacillus acidoterrestris. This represents a major challenge for the beverage industry. The goals of this study were to: i) investigate the UV-C inactivation (annular thin film unit, actinometrical delivered fluence: 795-1270 mJ/cm², 10-15 min, 20 °C, 1.8 L/h, Re_h = 391-1067, recirculation mode operation) and the evolution during refrigerated storage of A. acidoterrestris ATCC 49025 spores and single or composite Escherichia coli ATCC 25922 in isotonic sports drinks (ISDs) made from orange (orange-ISD, UVT% = 81) or orange-banana-mango-kiwi-strawberry-lemon juices (multi-fruit-ISD, UVT% = 91), compared to a turbid orange-tangerine juice (OT juice, UVT% = 40); ii) assess the effect of pH, °Brix, A_254nm, turbidity, colour and particle size of the ISDs and juice on microbial inactivation, iii) evaluate the evolution of native microbiota during cold storage, iv) investigate the Coroller, biphasic, Weibull, and Weibull-plus-tail models' ability to describe microbial inactivation and v) measure 5-hydroxymethylfurfural (HMF) formation. The modified biodosimetry method was used to calculate the germicidal UV-C fluences. Heat pasteurization (T-coil, 80 °C/6 min) was evaluated as the control treatment. UV-C was highly effective at inactivating E. coli as 4.1-5.1 and 4.5-5.6 log reductions were determined in the multi-fruit-ISD and orange-ISD, respectively, barely impacted by the background microbiota. No significant differences were recorded for the inactivation of E. coli in the UV-C and T-coil systems. Whereas, a significantly higher inactivation of A. acidoterrestris spores was achieved by UV-C (3.7-4.0 log reductions), compared to the negligible one achieved by the thermal treatment. Even though E. coli inactivation curves were similar in shape, UV-C was less effective when a cocktail of other E. coli strains was present. In comparison to the OT juice, the ISDs' inactivation kinetics were markedly different in shape, with a rapid decrease in population during the first minutes of treatment. The germicidal fluence (H_{d biod}) corresponding to A. acidoterrestris (19.1 mJ/cm²) was selected as it was higher than the one obtained for E. coli (11.0 mJ/cm²). UV-C induced 2.8- or 1.3 and 2.3- or 0.8 log-reductions of total aerobes or moulds and yeasts in the multi-fruit-ISD and orange-ISD, respectively. Compared to the other models, the Coroller and biphasic models showed a better fit and more accurate parameter estimates. UV-C-induced HMF production was not significant in the ISDs. The current study found that the UV-C treatment was more effective than typical heat pasteurization for inactivating A. acidoterrestris spores in isotonic drinks, following a similar trend for E. coli and native microbiota.

Effect of ultraviolet light-emitting diode processing on fruit and vegetable-based liquid foods: A review

Ultraviolet light-emitting diode (UV-LED) technology has emerged as a non-thermal and non-chemical treatment for preserving liquid fruit and vegetable foods. This technology uses ultraviolet light to interact with the food at different wavelengths, solving problems related to product stability, quality, and safety during storage. UV-LED treatment has been shown to affect microbe and enzyme inactivation, and it increases and improves retention of bioactive compounds. Moreover, computational simulations are a powerful and relevant tool that can be used optimize and improve the UV-LED process. Currently, there are a limited studies of this technology in liquid fruit and vegetable-based foods. This review gathers information on these food type and shows that it is a promising technology for the development of new products, is environmentally friendly, and does not require the addition of chemicals nor heat. This is relevant from an industrial perspective because maintaining the nutritional and organoleptic properties ensures better quality. However, due to the scarce information available on this type of food, further studies are needed.

Design consideration and modelling studies of ultrasound and ultraviolet combined approach for shelf-life enhancement of pine apple juice

Although both ultraviolet (UV) radiation and ultrasound (US) treatment have their capabilities in microbial inactivation, applying any one method alone may require a high dose for complete inactivation, which may affect the sensory and nutritional properties of pineapple juice. Hence, this study was intended to analyse and optimise the effect of combined US and UV treatments on microbial inactivation without affecting the selected quality parameters of pineapple juice. US treatment (33 kHz) was done at three different time intervals, viz. 10 min, 20 min and 30 min., after which, juice samples were subjected to UV treatment for 10 min at three UV dosage levels, viz. 1 J/cm2, 1.3 J/cm2, and 1.6 J/cm2. The samples were evaluated for total colour difference, pH, total soluble solids (TSS), titrable acidity (TA), and ascorbic acid content; total bacterial count and total yeast count; and the standardization of process parameters was done using Response Surface Methodology and Artificial Neural Network. The results showed that the individual, as well as combined treatments, did not significantly impact the physicochemical properties while retaining the quality characteristics. It was observed that combined treatment resulted in 5 log cycle reduction in bacterial and yeast populations while the individual treatment failed. From the optimization studies, it was found that combined US and UV treatments with 22.95 min and1.577 J/cm2 ensured a microbiologically safe product while retaining organoleptic quality close to that of fresh juice.

A Comprehensive Review on Grape Juice Beverage in Context to Its Processing and Composition with Future Perspectives to Maximize Its Value

Red and purple grape juices (GJs) have long been consumed worldwide for their unique taste and nutritive value. Moreover, grape is postulated to play an important role in the improvement of cardiovascular risk factors owing to its rich polyphenol content. Little is known regarding GJ’s holistic chemistry and functionality as compared to those of other fruit juices. This review aims to compile the state-of-the art chemistry of colored grape juices and in context to its analysis and nutritional values. Further, a review of potential contaminants to be introduced during manufacturing and other factors that influence juice quality and or health effects are presented to help maximize GJ’s quality. A comparison between analytical methods for juice QC establishment is presented employing hyphenated platforms versus direct spectroscopic techniques. The enrichment of the colored skin with a myriad of phenolics poses it as a functional beverage compared to that of skinless juice.

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Chemical and Sensory Characteristics of Fruit Juice and Fruit Fermented Beverages and Their Consumer Acceptance

Recent social, economic, and technological evolutions have impacted consumption habits. The new consumer is more rational, more connected and demanding with products, more concerned with the management of the family budget, with the health, origin, and sustainability of food. The food industry over the last few years has shown remarkable technological and scientific evolution, with an impact on the development and innovation of new products using non-thermal processing. Non-thermal processing technologies involve methods by which fruit juices receive microbiological inactivation and enzymatic denaturation with or without the direct application of low heat, thereby lessening the adverse effects on the nutritional, bioactive, and flavor compounds of the treated fruit juices, extending their shelf-life. The recognition of the nutritional and protective values of fruit juices and fermented fruit beverages is evident and is attributed to the presence of different bioactive compounds, protecting against chronic and metabolic diseases. Fermentation maintains the fruit's safety, nutrition, and shelf life and the development of new products. This review aims to summarize the chemical and sensory characteristics of fruit juices and fermented fruit drinks, the fermentation process, its benefits, and its effects.

Wine yeast species show strong inter- and intra-specific variability in their sensitivity to ultraviolet radiation

While the trend in winemaking is toward reducing the inputs and especially sulphites utilization, emerging technologies for the preservation of wine is a relevant topic for the industry. Amongst yeast spoilage in wine, Brettanomyces bruxellensis is undoubtedly the most feared. In this study, UV-C treatment is investigated. This non-thermal technique is widely used for food preservation. A first approach was conducted using a drop-platted system to compare the sensitivity of various strains to UV-C surface treatment. 147 strains distributed amongst fourteen yeast species related to wine environment were assessed for six UV-C doses. An important variability in UV-C response was observed at the interspecific level. Interestingly, cellar resident species, which are mainly associated with wine spoilage, shows higher sensitivity to UV-C than vineyard-resident species. A focus on B. bruxellensis species with 104 screened strains highlighted an important effect of the UV-C, with intra-specific variation. This intra-specific variation was confirmed on 6 strains in liquid red wine by using a home-made pilot. 6624 J.L^-1 was enough for a reduction of 5 log₁₀ of magnitude for 5 upon 6 strains. These results highlight the potential of UV-C utilization against wine yeast spoiler at cellar scale.

Continuous-flow UV-C processing of kale juice for the inactivation of E. coli and assessment of quality parameters

Ultraviolet-C (UV-C) light is a non-thermal method for improving the safety and shelf-life of cold-pressed juices with minimal impact on quality and nutrition. Most previous studies have investigated fruit juices as opposed to particulate dense leafy green juices with very low UV transmittance (UVT). Pure kale juice is a common juice ingredient and represents the worst-case scenario in terms of low UVT green juices. This study validated the use of continuous benchtop UV-C treatment at 253.7 nm for 5-log reduction of non-pathogenic Escherichia coli P36 in kale juice. An average absorbed fluence of 108.3 mJ cm^-2 resulted in a 5.8 log reduction of E. coli P36. At a fluence comparable to that reported for commercial juice processing (74.0 mJ cm^-2), kale juice exhibited a decrease in absorption coefficient, while sedimentation, supernatant browning and pectin methylesterase activity increased with no effect on the chlorophyll content, colour, viscosity or antioxidant content.

Bile Salt-Stimulated Lipase Activity in Donor Breast Milk Influenced by Pasteurization Techniques

Breast milk contains bile salt-stimulated lipase (BSSL), which significantly increases the fat digestion capacity of newborns who have limited pancreatic lipase secretion in the first few months after birth. Problematically, Holder pasteurization used in non-profit milk banks to ensure the microbiological safety of donor milk for infants, particularly preterm infants (<37 weeks gestation age), destroys milk BSSL, thus limiting infant fat absorption capacity. Alternative strategies are needed to ensure the safety of donor milk while preserving BSSL activity. Three alternative pasteurization techniques—high-pressure processing (HPP, 550 MPa, 5 min), gamma cell irradiation (IR, 2.5 Mrads) and UV-C (254 nm, 0–33,000 J/L)—were compared with Holder pasteurization (low-temperature long-time, LTLT, 62.5°C, 30 min) for retention of BSSL activity in donor breast milk. As the time required for donor milk pasteurization by UV-C in published methods was not clear, donor breast milk was spiked with seven common bacterial strains and treated by UV-C for variable time periods and the minimum UV-C dosage required to achieve a 5-log₁₀ reduction of CFU/mL was determined. Eight thousand two hundred fifty J/L of UV-C exposure was sufficient to achieve 5-log₁₀ reduction of each of bacterial targets, including Bacillus and Paenibacillus spores. The retention of BSSL activity was highest after HPP (retaining 62% of the untreated milk BSSL activity), followed by UV-C (16,500 J/L), IR and LTLT (35, 29, and 0.3% retention, respectively). HPP was an effective alternative to pasteurize milk with improved retention of BSSL activity compared to Holder pasteurization. Future work should investigate the effect of alternative pasteurization techniques on the entire array of bioactive components in donor breast milk and how these changes affect preterm infant health outcomes. Implementation of HPP technique at milk banks could improve donor milk-fed infant fat absorption and growth.

Emerging chemical and physical disinfection technologies of fruits and vegetables: a comprehensive review

With a growing demand for safe, nutritious, and fresh-like produce, a number of disinfection technologies have been developed. This review comprehensively examines the working principles and applications of several emerging disinfection technologies. The chemical treatments, including chlorine dioxide, ozone, electrolyzed water, essential oils, high-pressure carbon dioxide, and organic acids, have been improved as alternatives to traditional disinfection methods to meet current safety standards. Non-thermal physical treatments, such as UV-light, pulsed light, ionizing radiation, high hydrostatic pressure, cold plasma, and high-intensity ultrasound, have shown significant advantages in improving microbial safety and maintaining the desirable quality of produce. However, using these disinfection technologies alone may not meet the requirement of food safety and high product quality. Several hurdle technologies have been developed, which achieved synergistic effects to maximize lethality against microorganisms and minimize deterioration of produce quality. The review also identifies further research opportunities for the cost-effective commercialization of these technologies.

Development and quality assessment of a turbid carrot-orange juice blend processed by UV-C light assisted by mild heat and addition of Yerba Mate (Ilex paraguariensis) extract

Carrot-orange juice processed by UV-C (10.6 kJ/m²) assisted with mild heat (H, 50 °C) and yerba mate addition (E) was obtained. UV-C/H + E treated juice was examined for native flora, polyphenol content (PC), total antioxidant activity (TAA), colour, turbidity, °Brix and pH along storage (4 °C). Consumer profiling studies were performed. UV-C/H + E provoked 2.6-5.7 native flora log reductions, preventing from recovery during 24 day-storage. The UV-C/H + E juice exhibited a significant increase in PC (720.2 µg/mL) and TAA (5.5 mg/mL) compared to untreated (PC = 205.0 µg/mL/TAA = 0.7 mg/mL) and single treated juices (PC = 302.1-408.0 µg/mL/TAA = 0.7-2.4 mg/mL), remaining constant throughout storage. UV-C/H + E juice exhibited scarce changes in colour. Nevertheless, increases in °Brix and turbidity were observed compared to single treatments. A cluster sensory analysis revealed that one group showed a marked interest in UVC/H + E beverages with herbal taste and strong aroma. CATA question revealed that some improvements should be introduced in order to satisfy the consumers' ideally beverage.