Preservation Of Juice Research Articles

Highly Efficient AIE-Active palmatine photosensitizer for photodynamic inactivation of Listeria monocytogenes in apple juice preservation

Photodynamic sterilization is a promising alternative to conventional antibacterial approaches with merits of high efficiency and safety. The exploration of aggregation-induced emission (AIE)-type photosensitizers from natural sources is highly valued by researchers and food industry. Herein, the use of palmatine (PA), an aggregation-induced emission-active natural product from traditional Chinese medicine, as photosensitizers for photodynamic inactivation of a tenacious foodborne pathogen of Listeria monocytogenes is investigated. Antibacterial and antibiofilm activity against L. monocytogenes of PA-mediated photodynamic process were first assessed. The results showed that PA-mediated photodynamic process could inhibit the growth of L. monocytogenes, and the minimum bactericidal concentration was determined as 80 μM. At this PA dosing level, well-established biofilms of L. monocytogenes can be effectively destroyed under light irritation. Afterward, cell- and gene-level investigations were conducted to explore the antibacterial mechanism. It is concluded that the exceptional photodynamic antibacterial activity of PA against L. monocytogenes is attributed to the disruption of the cell wall and membrane, increased cell permeability, leakage of functional proteins, and damage to DNA structure. Subsequently, PA-mediated photodynamic process was applied to reduce bacterial activity in apple juice while preserving its quality. Overall, this work highlights the significant potential of PA-mediated photodynamic strategy for controlling foodborne pathogens in food systems.

Effect of antifungal proteins (AFPs) on the viability of heat-resistant fungi (HRFs) and the preservation of fruit juices

The control of heat-resistant fungi (HRFs), which cause spoilage of heat-treated fruit products, is considered a challenge for the fruit juice and beverage industry and requires new strategies for the development of antifungal compounds. In this study, four antifungal proteins (AFPs) from Penicillium digitatum (PdAfpB) and Penicillium expansum (PeAfpA, PeAfpB and PeAfpC), were evaluated against conidia from a representative collection of HRFs. A total of 19 strains from 16 different species belonging to the genera Aspergillus, Hamigera, Paecilomyces, Rasamsonia, Sarocladium, Talaromyces and Thermoascus were included in the study. PeAfpA and PdAfpB exhibited potent antifungal activity in synthetic media, completely inhibiting the growth of most of the fungi evaluated in the range of 0.5–32 μg/mL. The efficacy of the four AFPs was also tested in fruit juices against ascospores of five HRFs relevant to the food industry, including P. fulvus, P. niveus, P. variotii, A. fischeri and T. flavus. PdAfpB was the most effective protein in fruit juices, since it completely inhibited the growth of the five species tested in at least one of the fruit juices evaluated. This is the first study to demonstrate the activity of AFPs against fungal ascospores. Finally, a challenge test study showed that PdAfpB, at a concentration of 32 μg/mL, protected apple fruit juice artificially inoculated with ascospores of P. variotii for 17 days, highlighting the potential of the protein as a preservative in the fruit juice industry.

Preparation of plant-derived compounds/chitosan/gelatin antifungal film and investigation of its control effect on Zygosaccharomyces rouxii contamination in concentrated apple juice

The purpose of this work is to develop a plant-derived compounds (PDCs)/chitosan (CS)/gelatin (GL) packaging lining film with high inhibitory activity against the contamination of Zygosaccharomyces rouxii in concentrated apple juice. The PDCs with high anti-Z. rouxii activity were selected from 19 PDCs for pairwise combining, and the combination with synergistic anti-Z. rouxii effect was selected to prepare nanoemulsion. Then, the effect of PDCs emulsion on mechanical and anti-Z. rouxii properties of CS/GL film was investigated. Finally, the prepared PDCs/CS/GL film was used as packaging lining to explore the preservation effect on concentrated apple juice. The results showed that the combination of trans-cinnamaldehyde and geraniol (4:6, v/v) presented the highest synergistic anti-Z. rouxii effect (the value of fractional inhibitory concentration index equaling 0.25). Addition of trans-cinnamaldehyde-geraniol nanoemulsion reduced mechanical properties of CS/GL film, but improved anti-Z. rouxii activity. The CS/GL film containing 1.5 % (v/v) trans-cinnamaldehyde-geraniol nanoemulsion showed high anti-Z. rouxii activity and did not affect the quality of concentrated apple juice, which could be used as a packaging lining for preservation of concentrated apple juice. The PDCs/CS/GL packaging lining film prepared in this work not only presented an enduring and effective inhibitory effect on Z. rouxii contamination in concentrated apple juice, but also avoided the influences of trans-cinnamaldehyde and geraniol on the quality of concentrated apple juice, which provided a new idea for the development of food preservation packaging film.

Membrane assisted Pulsed Electric Field (M-PEF) a novel technique for preservation of functional and biological properties of sugarcane juice.

Abstract According to market prospects there is a demand for the bottled fresh sugarcane juice than any other fruit based beverages because of its nutritional and therapeutic properties. Sugarcane juice short shelf life and deterioration are linked to the existence of active enzymes like peroxidase and polyphenol oxidase as well as its microbial composition. The membrane assisted pulsed electric field technology (M-PEF) was used for this experiment in which the hollow spiral wound ultra-filter membrane for 10 kDa pore size at 1 bar pressure employed as a pretreatment to pulsed electric field processing for the treatment of sugarcane juice. The process parameters are 20, 30, and 40 kV/cm field strength for the pulse width of 100, 150, and 200 μs. The reduction of 92% in polyphenol oxidase and 80% in peroxidase enzyme activity was achieved due to Pulsed electric field at a field strength and pulse width of 30 kV/cm for 150μs respectively retaining the overall quality of the sugarcane juice and there was 85-95% reduction was observed in the protein and polysaccharide content of the sugarcane juice due to the membrane filtration pore size exclusion effect. Ascorbic acid content was retained in the M-PEF samples while increasing its antioxidant capacity. The experiment results showed that due to Pulsed electric field treatment there was 3 log reductions are observed on total plate count. This technology showed that, it can be used as novel technique for the preservation of the fresh juices.

Chemical kinetics and thermodynamics of PPO activity, colour changes and microbial degradation during blanching of the sugarcane billets.

Sugarcane juice, which has a short shelf life, is a popular thirst-quenching and rejuvenating beverage worldwide. The limited shelf life is a result of changes in polyphenol oxidase (PPO) activity, total plate count (TPC) and color attributes (L*, a* and b*-values). We hypothesized that chemical kinetics and thermodynamics of blanched sugarcane cane juice causing alterations in PPO, TPC, and L, a* and b*-values will address the challenges of sugarcane juice preservation. Sugarcane billets were blanched at variable time-temperature combinations in the range 0-20 min and 70-90 °C. Reaction rates increased with increasing temperature; PPO activity, TPC and colour followed first-order kinetics. PPO activity had an activation energy (Ea) of 81 kJ mol-1. The half life (t½) dropped from 16.5 to 3.47 min and decimal reduction time (D-values) dropped from 54.83 to 11.52 min. Thus reactions were temperature-sensitive. Thermodynamic studies indicated an endothermic (positive enthalpy values, ΔH > 0; 78.10 kJ mol-1) and reversible process (negative entropy values ΔS < 0; -0.044 kJmol-1 K-1). Michaeli-Menten constant (Km) and maximum velocity (Vmax) of PPO activity were determined by adding variable lemon juice concentrations in sugarcane juice. As the Km values increased (from 5.53 to 15.81 mm) and Vmax values decreased (from 666.67 to 384.61 UmL-1), a Lineweaver-Burk plot suggested decreased PPO affinity of sugarcane juice. The results of the present study indicate that studies on chemical kinetics and thermodynamics (PPO, TPC and L, a* and b*-values) of blanched sugarcane cane juice shall mitigate challenges of sugarcane juice preservation. © 2024 Society of Chemical Industry.

Optimization of Fruit Juice Preservation Utilizing Chitosan and Chitosan Nanoparticle: A Central Composite Design

In this study, the shelf life of sweet lime juice was tested using chitosan and chitosan nanoparticles produced through the Ionic-gelation process. The results showed that the chitosan nanoparticles had a greater impact on extending the shelf life than chitosan alone. The pH, turbidity, and aerobic count of the juice were measured after the chitosan and chitosan nanoparticles were added, and response surface methodology was used to optimize these factors. The optimal pH range for chitosan was between 3.0 and 4.6, and for chitosan nanoparticles it was between 3.0 and 4.9. The maximum turbidity occurred at a chitosan concentration of 0.5-2.5 g/L and storage days of 1.0-2.0. The results were found to be significant through analysis of variance, and the model had a high level of significance and good fit according to the determination coefficient.

Simulation of single-effect and triple-effect evaporator for fruit juice concentration using Aspen HYSYS

Abstract One of the most popular methods of fruit juice preservation is concentration since it offers a variety of advantages, like decreased volume, weight, packing, simpler transportation and handling, and a longer shelf life. The present paper studied the evaporation of fruit juice in single- and triple-effect evaporators using Aspen HYSYS software. The amount of juice was 3000 kg/h, and its concentration was raised from 10 to 50 °Brix. Four evaporator layouts were estimated and optimized: single-effect, modified single-effect, forward triple-effect, and triple-effect in parallel. It is a study of the effect of the temperature of saturated steam (120–300 °C) used to concentrate the juice and the pressure of the product (15–50 kPa) on the mass flow rate of steam required, economy, and overall heat transfer coefficient times area (UA) of the evaporator. The best operating conditions for each type of evaporation system were 15 kPa of the product’s pressure for all types of evaporators, 192, 240, 182, and 210 °C of the single-effect, modified single-effect, forward triple-effect, and parallel triple-effect, respectively. These operating conditions are equivalent to the steam required, economy, UA, and steam cost as follows: for each type, they were (3075, 338.4, 1224, and 1100 kg/h), (0.78, 7.1, 1.96, and 2.15), (40,182, 74,505, 539,987, 152,173 kJ/°C h), and (12.68 × 103, 12.76 × 103, 12.65 × 103, and 12.73 × 103 $/h), respectively.

Impact of Thermal, Ultrasonication, and Thermosonication Processes on the Quality Profile of Watermelon-Beetroot Juice Blend: A Comparative Study

Fruit juices are popular beverages that provide various health benefits due to their rich nutritional profile, but they are prone to microbial spoilage and quality deterioration. Thermal pasteurization is the conventional method to preserve fruit juices, but it causes undesirable changes in the physicochemical and nutritional value of the juices. Therefore, there is a need to develop alternative methods to ensure the microbial safety and quality of fruit juices. The aim of this study was to investigate the impact of thermal (95-100°C for 4 min), ultrasonication (US) (25 kHz for 5 and 10 min), and thermosonication (TS) (25 kHz at 40 and 50°C) processes on the quality profile of watermelon-beetroot juice blend, a novel juice formulation with enhanced nutritional and functional properties with 50 : 50 formulation. The samples were analysed for physicochemical (colour, pH, total soluble solids, and titratable acidity), bioactive (phenolic, flavonoid, antioxidant, and ascorbic acid contents), and microbiological (total plate count and yeast/molds) properties. The results showed that all the processed samples retained high total phenolic (756.33-842.33 μg GAE/g), total flavonoid (435.33-512.67 μg CE/g), and ascorbic acid (45.23-50.34 mg/100 mL) contents along with a high antioxidant potential (total antioxidant capacity (274.14-305.33 μg AAE/g) and DPPH radical scavenging activity (33.05-42.18%)) while preserving the normal physicochemical characteristics and decreasing the microbial counts of all the processed blend juices. In conclusion, the US treatment (10 min) produced the juice blends with the best quality. The findings of this research suggest that thermal, US, and TS processes are promising technologies for the preservation of fruit juices and that watermelon-beetroot juice blend is a novel juice formulation with high nutritional and functional value. The results of this research might be useful to the processed fruit juice industry and the consumers who are looking for healthy and safe fruit juices.

The Effects of Jet-Milling and Pulsed Electric Fields on the Preservation of Spinach Juice Lutein Contents during Storage.

This study aimed to investigate the effects of jet-milling on the lutein extraction contents of spinach powder (SP), as well as the effects of pulsed electric field (PEF), as a non-thermal pasteurization technology, on the preservation of spinach juice (SJ) lutein contents. SP particles were divided into SP-coarse (Dv50 = 315.2 μm), SP-fine (Dv50 = 125.20 μm), and SP-superfine (Dv50 = 5.59 μm) fractions, and SP-superfine was added to SJ due to its having the highest contents of lutein extract. PEFs and thermal treatment were applied to evaluate the effects of preserving the lutein content of PEF during storage (25 days). The juice was then designated as untreated (no pasteurization), PEF-1,2 (SJ treated with PEF 20 kV/cm 110 kJ/L, 150 kJ/L), or Thermal-1,2 (SJ treated with 90 °C, 10 min and 121 °C, 15 min). The sizes and surface shapes of the superfine SP particles were more homogeneous and smoother than those of the other samples. SJ made with SP-superfine and treated with PEF had the highest lutein content and antioxidant activities among the group during storage. A complex of jet-milling and PEF could have great potential as a method to improve the lutein contents of lutein-enriched juice in the food industry.

Exploring the impact of cold plasma treatment on the antioxidant capacity, ascorbic acid, phenolic profile, and bioaccessibility of fruits and fruit juices

AbstractIn recent years, cold plasma (CP) has emerged as a promising preservation technology for fruit products. Several CP sources include dielectric barrier discharge, plasma jets, corona discharges, micro‐discharges, glow discharges, and gliding arc discharges. However, the effects of these different types of CP on the chemical compounds of fruits and juices are not fully understood. In this review, we summarize (I) the current knowledge on the use of CP for the preservation and processing of fruits and juices; (II) the diverse types of CP sources and explore their applications within a scientific context; (III) the physicochemical transformations that take place in fruits and juices following CP treatment; and (IV) the changes observed in antioxidant activity, vitamin C content, phenolic compounds, and their bioaccessibility. Numerous studies have explored CP's influence on microbial contamination, shelf life, enzymes, and various physicochemical changes. This review uniquely centers its attention on the impact of CP on bioactive phenolic compounds, their bioaccessibility, vitamin C content, and antioxidant activity in different types of fruits and fruit juices. Additionally, this review delves into the assessment of selected sensory properties, notably color, which is an important parameter for consumer acceptance. By focusing on these particular aspects, we aim to provide a targeted and comprehensive analysis of CP's effects on essential nutritional and quality attributes of fruits and fruit juices, distinct from the broader spectrum covered in the existing literature.

Benefits of isochoric freezing for carrot juice preservation.

Isochoric freezing (IF) at -5°C/77 and -10°C/100MPa was used to preserve carrot juice for 12 weeks. The juice qualities were compared to those using heat treatment (HT) at 95°C for 15s followed by cold storage at 4°C. The native population of total aerobic bacteria, yeasts, and molds in isochoric frozen juice remained below the detection limit for 12 weeks. In comparison, microbes started to grow in heat-treated juices after 3 weeks of refrigeration. The color of isochoric frozen juice appeared more deep orange than the fresh juice due to an increase in carotenoid extractability. IF was not effective in reducing the activities of peroxidase, polyphenol oxidase, and pectin methyl esterase compared with HT. However, the isochoric samples showed higher carotenoid content, polyphenol content, and antioxidant capacity compared to the fresh and heat-treated juices. PRACTICAL APPLICATION: Isochoric freezing was used to produce carrot juice with extended shelf life. Isochoric freezing could be a beneficial alternative to conventional heat treatment for carrot juice processing as the applied pressures reached total inactivation levels of spoilage microorganisms. Moreover, the low processing temperatures better retained desirable compounds and quality attributes of fresh juice throughout its shelf life.

Optimizing Quality and Shelf-Life Extension of Bor-Thekera (Garcinia pedunculata) Juice: A Thermosonication Approach with Artificial Neural Network Modeling

This study investigated the quality characteristics of pasteurized and thermosonicated bor-thekera (Garcinia pedunculata) juices (TSBTJs) during storage at 4 °C for 30 days. Various parameters, including pH, titratable acidity (TA), total soluble content (TSSs), antioxidant activity (AA), total phenolic content (TPC), total flavonoid content (TFC), ascorbic acid content (AAC), cloudiness (CI) and browning indexes (BI), and microbial activity, were analyzed at regular intervals and compared with the quality parameters of fresh bor-thekera juice (FBTJ). A multi-layer artificial neural network (ANN) was employed to model and optimize the ultrasound-assisted extraction of bor-thekera juice. The impacts of storage time, treatment time, and treatment temperature on the quality attributes were also explored. The TSBTJ demonstrated the maximum retention of nutritional attributes compared with the pasteurized bor-thekera juice (PBTJ). Additionally, the TSBTJ exhibited satisfactory results for microbiological activity, while the PBTJ showed the highest level of microbial inactivation. The designed ANN exhibited low mean squared error values and high R2 values for the training, testing, validation, and overall datasets, indicating a strong relationship between the actual and predicted results. The optimal extraction parameters generated by the ANN included a treatment time of 30 min, a frequency of 44 kHz, and a temperature of 40 °C. In conclusion, thermosonicated juices, particularly the TSBTJ, demonstrated enhanced nutritional characteristics, positioning them as valuable reservoirs of bioactive components suitable for incorporation in the food and pharmaceutical industries. The study underscores the efficacy of ANN as a predictive tool for assessing bor-thekera juice extraction efficiency. Moreover, the use of thermosonication emerged as a promising alternative to traditional thermal pasteurization methods for bor-thekera juice preservation, mitigating quality deterioration while augmenting the functional attributes of the juice.

Microbial, Physicochemical and Sensory Quality of Freshly Extracted Apple and Cucumber Juice Subjected to Preservatives and Storage Conditions

Fruit juices are commonly consumed for their refreshing attribute, nutritive values and health benefits. Fruit juice samples were treated with 0.5 g/ml garlic, 0.5 g/ml ginger, 0.25 g/ml mix of ginger and garlic and 0.05% (w/v) of sodium benzoate respectively where the ginger, garlic and sodium benzoate serve as natural and artificial preservatives. Their effects on the fruit juices were evaluated during 8 days of storage at 4°C and ambient temperature (28±2°C). Juice treated with sodium benzoate had the least microbial contamination while the untreated juice had the highest. The bacterial isolated from the samples were Staphylococcus sp, Bacillus sp. (Most occurring bacteria isolated), Micrococcus sp, and lactobacillus sp. The fungi isolated in the course of the study were Aspergillus sp, Rhizopus sp and Penicillium sp. (The highest occurred fungi isolated). There was a marginal decrease in pH values across treatments in stored juices with juice stored at 4°C showing the least change in pH compared to that stored at ambient temperature. The results obtained show that the preservatives exhibited an antimicrobial effect on the microbial load. The Total titratable acidity of all samples increased with time at ambient temperature and decreased at refrigerated temperature. The ascorbic acid content of both juices samples at storage temperatures decreased after the storage period due to the high sensitivity of vitamin C to oxygen, light, heat, etc. In conclusion, the findings of this study generally indicate that combination of chemical and natural preservation together with refrigeration is suitable for the preservation of fruit juice for a long time. Chemical preservatives can be recommended to be replaced with natural preservatives such as ginger and garlic, since the process is inexpensive and easy. However, preservation of fruit juice at ambient temperature for a long time should be discouraged to reduce microbial contamination.

The potential use of supercritical carbon dioxide in sugarcane juice processing

Sugarcane juice is a nutritious and energetic drink. For its processing, the use of supercritical carbon dioxide (SC-CO2) technology as an intervention potentially capable of rendering a high quality product can be considered. This study evaluated the combined effect of SC-CO2 and mild temperatures, primarily aiming for the reduction of endogenous microorganisms and enzymes in sugarcane juice (pH~5.5). Pressures (P) ranging from 74 to 351 bar, temperatures (T) between 33 and 67 °C, and holding times (t) between 20 and 70 min were tested in a central composite rotational design. Seventeen trials were performed, comprising three replicates at the central points. Counts of aerobic mesophiles, molds and yeasts, lactic acid bacteria and coliforms at 45 °C, determination of polyphenol oxidase (PPO) and peroxidase (POD) activities, and measurement of color parameters in freshly extracted and processed juice’s samples were carried out. The pH of fresh and processed juice varied between 4.6 and 6.0, and between 4.6 and 6.3, respectively. The number of decimal reductions achieved in mesophiles, molds and yeasts, lactic acid bacteria and coliforms varied between 0.1 and 3.9, 2.1 and 4.1, 0.0 and 2.1, and 0.3 to 2.5, respectively. The percentages of PPO reduction ranged from 3.51% to 64.18%. Regarding the POD, reductions between 0.27% and 41.42% were obtained. Color variations between fresh and processed samples varied between 2.0 and 12.3. As for mesophiles, molds and yeasts reduction, and soluble solids variation, none of the variables or their interactions were significant. In terms of polyphenol oxidase (PPO) reduction, only t was significant; however, T, t, and the interaction between them significantly affected the peroxidase (POD) reduction. In regards to pH variation, P, and the interaction between T and t were significant. P, T, t, and the interaction between T and t played a significant effect on color. The combination of mild temperatures and SC-CO2 can be potentially used for cane juice preservation.

Approaches and Technologies for Preservation of Sugarcane juice: A Review

Every region of India has access to the cooling sweet soft drink known as sugarcane juice. It is an essential product on the world market since it has great health advantages. Sugarcane juice competes with other soft drinks in the market pushed by health-conscious consumers, and the sugarcane growers profit financially. To extend the shelf life of sugarcane juice, processing must be combined with the development of appropriate preservation methods. Researchers have looked into a variety of sugarcane juice preservation techniques, including chemical, thermal, and non-thermal techniques. Pasteurization is one of the many methods that are used for preserving sugarcane juice. Pasteurization, however, results in the loss of flavor, aroma, colour, taste, and vital nutrients. Non-thermal procedures, which can preserve the nutritional and sensory qualities of fresh juices, are now receiving more attention. This review article examines numerous preservation methods for sugarcane juice, analyses them, and suggests a course of action to assist determine the best method for doing so. Different criteria for different types of technologies are discussed with their advantages and drawbacks. Technologies which do not use chemical additives have also been discussed, while taking their industrial scalability and economical aspects under consideration. Prime focus is kept on developing a technology which is economical, industrially acceptable and greener for the environment.

Comparative Study of Effect of different Processing Method on Preservation of Lime-flavored Dragon Fruit Juice

Comparative Study of Effect of different Processing Method on Preservation of Lime-flavored Dragon Fruit Juice

Antimicrobial and Antioxidant Activities of Lemongrass Oil (Cymbopogon citratus), in Preservation of Fresh Orange Juice

Antimicrobial and Antioxidant Activities of Lemongrass Oil (Cymbopogon citratus), in Preservation of Fresh Orange Juice

Effect of Thermosonication on the Nutritional Quality of Lapsi (Choerospondias axillaris) Fruit Juice: Application of Advanced Artificial Neural Networks.

This study explored the effect of thermosonication on the nutritional properties of lapsi (Choerospondias axillaris) fruit juice. The intent of the present investigation was to process lapsi fruit juice using both thermosonication and thermal pasteurisation and to compare the effects of these treatments on the juice's physicochemical, nutritional, and microbiological qualities. In order to maximise the retention of nutritional properties, enhance juice quality, and boost efficiency, an artificial neural network (ANN) model was also developed to forecast the optimisation of process parameters for the quality of lapsi fruit juice. This study establishes a novel experimental planning method using an ANN to multi-objectively optimise the extraction process and identify the ideal extraction conditions for thermosonication (50, 75, and 100% amplitude at 30, 40, and 50 °C for 15, 30, 45, and 60 min) to augment lapsi juice's nutritional and microbiological properties by improving certain attributes such as ascorbic acid (AA), antioxidant activity (AOA), total phenolic content (TPC), total flavonoid content (TFC), total plate count, and yeast and mould count (YMC). The maximum values for AA (71.80 ± 0.05 mg/100 mL), AOA (74.60 ± 0.28%), TPC (187.33 ± 0.03 mg gallic acid equivalents [GAE]/mL), TFC (127.27 ± 0.05 mg quercetin equivalents [QE]/mL), total plate count (not detected), and YMC were achieved in thermosonicated lapsi juice (TSLJ) under optimal conditions. For AA and TFC, the optimal conditions were 100% amplitude, 40 °C, and 45 min. For AOA and TPC, the optimal conditions were 100% amplitude, 40 °C, and 60 min, and for YMC, the optimal conditions were 100% amplitude, 50 °C, and 60 min. According to the findings, thermosonicated juices have improved nutritional properties, making them an excellent source of bioactive elements for use in both the food and pharmaceutical sectors. According to this study, ANN has been identified as a valuable tool for predicting the effectiveness of lapsi fruit juice extraction, and the application of thermosonication as an approach for lapsi juice preservation could be a potential successor to thermal pasteurisation. This approach can help to minimise or hinder quality degradation while improving the juice's functionality.

Effect of High-Powered Ultrasound on Bioactive Compounds and Microbiological Stability of Juices—Review

Extending the shelf life of fruit and vegetable juices plays a key role in improving food security. Ultrasonic technology can be an effective method in the process of replacing traditional heat treatment. It offers a number of benefits, such as better product quality expressed as a higher content of bioactive substances and the preservation of the natural sensory characteristics of the juice: consistency, colour, taste and smell. This paper discusses the methods of ultrasound generation, the equipment used and advances in the construction of ultrasound devices. The influence of ultrasounds on the physical and chemical properties of juices was also analysed, with particular emphasis on bioactive substances and the effectiveness of ultrasonic treatment in the inactivation of microorganisms and enzymes. Prospects and trends in the development of ultrasonic techniques that can effectively increase the efficiency of the ultrasonic juice preservation process are also described. Sonication used alone or with other processing techniques makes it possible to achieve a positive effect on the quality of consumed fruit and vegetable juices.

Preparation and characterization of a solid dispersion of Hexahydrocolupulone and its application in the preservation of fresh apple juice.

Hops extracts and their derivatives have many important biological activities, among them, excellent antibacterial and antioxidant properties make them a promising food preservative. However, poor water solubility limits their application in the food industry. This work aimed to improve the solubility of Hexahydrocolupulone (HHCL) by preparing solid dispersion (SD) and investigating the application of the obtained products (HHCL-SD) in actual food systems. HHCL-SD was prepared by solvent evaporation with PVPK30 as a carrier. The solubility of HHCL was dramatically increased to 24.72mg/mL（25 ℃)by preparing HHCL-SD, much higher than that of raw HHCL (0.002mg/mL). The structure of HHCL-SD and the interaction between HHCL and PVPK30 were analyzed. HHCL-SD was confirmed to have excellent antibacterial and antioxidant activities. Furthermore, the addition of HHCL-SD proved to be beneficial for the sensory, nutritional quality, and microbiological safety of fresh apple juice, hence prolonging its shelf-life.