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

Processing of verjuice by ultrasound-assisted microwave heating: An assessment on the enzyme activity retention, technological parameters, and bioactive properties

The present study evaluated the effect of ultrasonication prior to microwave heating applied at 60 °C, 70 °C, and 80 °C on the quality characteristics of verjuice. The sole microwave heating and conventional heating were also performed at the same temperature levels, and effectiveness of three different treatments were evaluated. The required treatment times were decided based on obtaining <10% pectin methylesterase (PME) activity, and ultrasound pretreatment provided the least heating durations. Turbidity, browning index, and viscosity values increased by 3.4 to 14.8-fold, 0.24 to 1.26-fold, and 9.2% to 48.0%, respectively, after all thermal treatments, while Brix values decreased by 1.4% to 15.7%. Ultrasound pretreatment revealed relatively lower browning index in all temperature levels, and almost the highest viscosity values were obtained in sonication pretreated microwave heating as compared with sole microwave and conventional heating. The minimum turbidity value (0.035) was determined in ultrasound-assisted microwave heating at 60 °C. The highest antioxidant capacity (DPPH and ABTS) values were achieved by ultrasound-assisted microwave heating (up to 4.96 and 28.4 mmol Trolox equivalent (TE)/kg, respectively) followed by microwave heating (up to 4.30 and 27.0 mmol TE/kg) and conventional heating (up to 3.72 and 26.8 mmol TE/kg). Furthermore, ultrasonication resulted in better retentions of PME residual activity during 60 days of refrigerated storage (4 °C). Ultrasound pretreatment prior to microwave heating could be a convenient approach for juice processing by reducing the required treatment time and by conserving the quality parameters.

Thermal and non-thermal treatments in the processing of cagaita nectar - Eugenia dysenterica

This work aimed to analyze cagaita nectar subjected to different thermal and non-thermal treatments regarding its quality over 30 days of storage (5 °C). Ultra (U) and thermosonication (T) were the techniques used for 30 and 60 minutes of processing samples. These techniques proved to be effective to preserve physicochemical quality, regarding rheology and texture, since ultra and thermosonicated samples had their consistency increased when compared to the pasteurized sample over 30 days, a desirable factor for a fruit nectar. Samples treated more intensely with ultrasound and temperature (Pasteurized, U 25 °C/60 min and T 60 °C/ 30 min) showed higher soluble solids content. The sample U 25 °C/60 min increased its brightness, reduced its firmness and also its consistency after 30 storage days. For all samples there was an increase in carotenoids content and a maintenance of viscosity and cohesiveness (texture) over 30 days, thus indicating that the used treatments can be feasible instead of pasteurization, maintaining the shelf life of cagaita nectar in the time evaluated.

Effect of Ultrasound and High Hydrostatic Pressure Processing on Quality and Bioactive Compounds during the Shelf Life of a Broccoli and Carrot By-Products Beverage

Vegetable beverages are a convenient strategy to enhance the consumption of horticultural commodities, with the possibility of being fortified with plant by-products to increase functional quality. The main objective was to develop a new veggie beverage from broccoli stalks and carrot by-products seasoned with natural antioxidants and antimicrobial ingredients. Pasteurization, Ultrasound (US), and High Hydrostatic Pressure (HHP) and their combinations were used as processing treatments, while no treatment was used as a control (CTRL). A shelf-life study of 28 days at 4 °C was assayed. Microbial load, antioxidant capacity, and bioactive compounds were periodically measured. Non-thermal treatments have successfully preserved antioxidants (~6 mg/L ΣCarotenoids) and sulfur compounds (~1.25 g/L ΣGlucosinolates and ~5.5 mg/L sulforaphane) throughout the refrigerated storage, with a longer shelf life compared to a pasteurized beverage. Total vial count was reduced by 1.5-2 log CFU/mL at day 0 and by 6 log CFU/mL at the end of the storage in HHP treatments. Thus, the product developed in this study could help increase the daily intake of glucosinolates and carotenoids. These beverages can be a good strategy to revitalize broccoli and carrot by-products with high nutritional potential while maintaining a pleasant sensory perception for the final consumer.

Influence of different pre-treatments on flavor quality of freeze-dried carrots mediated by carotenoids and metabolites during 120-day storage

Changes in carotenoids and volatiles (including β-carotene-metabolites) of freeze-dried carrots (FDC) treated by thermal/nonthermal-ultrasound (40 KHz, 10 min) and ascorbic (2%, w/v)-CaCl₂ (1%, w/v) solution ((H)UAA-CaCl₂) during a 120-day storage period were investigated. The results of HS-SPME/GC-MS showed that caryophyllene was the dominant volatile compound (70.80-275.74 µg/g, d.b) in FDC, and 144 volatile compounds were detected in 6 samples. Besides, 23 volatile compounds were significantly correlated with β-carotene content (p < 0.05), and β-carotene degraded to off-flavor compounds (β-ionone: 22.85-117.26 µg/g, β-cyclocitral: 0-113.84 µg/g and dihydroactindiolide: 4.04-128.37 µg/g) that had adverse effects on FDC flavor. However, UAA-CaCl₂ effectively preserved the total carotenoid content (793.37 µg/g), and HUAA-CaCl₂ reduced the off-odors (such as β-cyclocitral and isothymol) formation at the end of storage. These results indicated that (H)UAA-CaCl₂ treatments were conducive to the maintenance of carotenoids and the flavor quality of FDC.

Effects of Ginger and Garlic Powders on the Physicochemical and Microbiological Characteristics of Fruit Juices during Storage

Natural preservatives such as garlic and ginger can be added to the formulation of fresh fruit juices to encourage the consumption of health-promoting foods. In this study, the influence of garlic and ginger and the storage conditions on physicochemical and microbiological characteristics of fruit juices were investigated. The fruit juice assortments were produced from apple, apple and pumpkin, and apple and pomegranate and were treated with 0.5 g garlic powder, 0.5 g ginger powder, and 0.25 g mix of garlic and ginger powders. A total of 12 unpasteurized samples were produced, of which 3 were control samples. Samples stored at 20 and 4 °C were analyzed at 0, 3, 6, and 9 days for water activity (aw), pH, titratable acidity (TA), total soluble solids (TSS), electrical conductivity (EC), vitamin C, color parameters, total number of germs, yeasts, and molds, Listeria, Enterobacteriaceae, and Escherichia coli. Results showed that aw, pH, TSS, and vitamin C content decreased during storage of fruit juice samples, while TA increased. The lowest increase in total number of aerobic mesophilic germs was determined for the apple and pumpkin juice with garlic and ginger and apple juice with garlic.

Identification of Major B-Cell Linear Epitopes of Peach Allergen Pru p 3 Using Immune Slot-Blot Microarray Assay

Pru p 3, one of the most representative proteins of the lipid transfer proteins (LTPs), is responsible for clinical allergic reactions to food of peach origin. The identification of Pru p 3 epitopes is not comprehensive due to different methods and principles of epitope screening. In addition, evaluation of the stability of the epitopes and the validation of the immunological key amino acids still need further research. Therefore, in the present study, an immune slot-blot microarray assay was performed to screen the epitopes from Pru p 3 overlapping peptide library, and a new epitope (P-1, AA1-16, ITCGQVSSALAPCIPY) was identified and two identified epitopes were deeply investigated (P-2, AA12-27, PCIPYVRGGGAVPPAC; P-3, AA23-38, VPPACCNGIRNVNNLA). The stability of these epitopes was then verified by thermal processing treatment and digestion experiments. Moreover, the key amino acids of the three identified epitopes were obtained by epitope amino acid mutation combined with slot-blot experiments. These findings may contribute to the further understanding of Pru p 3 and the prevention of peach allergy.

Effects of ultrasound, heat, ascorbic acid and CaCl2 treatments on color enhancement and flavor changes of freeze-dried carrots during the storage period

Discoloration and unpleasant flavor were observed in freeze-dried carrots (FDC) during shelf life. This study aimed to investigate the effects of thermal/non-thermal pre-treatments and storage temperatures on the color and flavor of FDC during the 120-day storage. Results showed that terpenes and sulfur-containing organics were the main volatiles sensitive to the 60 °C treatment (p < 0.05). Nonenzymatic browning of FDC happened during storage, which was significantly positively related to moisture content (r = 0.63) and water activity (r = 0.84), while negatively correlated with total carotenoid content (TCC, r = -0.62). However, redness (29.66%), chroma (16.59%) and TCC (3.40%) of FDC at 120-day (25 °C) was effectively improved after the combination treatment of ultrasound (40 kHz, 100 W, 10 min) and ascorbic acid (2%, w/v)-CaCl₂ (1%, w/v) solution (UAA-CaCl₂), showing that carrots pre-treated with UAA-CaCl₂ and preserved at 25 °C facilitated the FDC storage.

Strategies to Improve the Potential Functionality of Fruit-Based Fermented Beverages

It is only recently that fermentation has been facing a dynamic revival in the food industry. Fermented fruit-based beverages are among the most ancient products consumed worldwide, while in recent years special research attention has been granted to assess their functionality. This review highlights the functional potential of alcoholic and non-alcoholic fermented fruit beverages in terms of chemical and nutritional profiles that impact on human health, considering the natural occurrence and enrichment of fermented fruit-based beverages in phenolic compounds, vitamins and minerals, and pro/prebiotics. The health benefits of fruit-based beverages that resulted from lactic, acetic, alcoholic, or symbiotic fermentation and specific daily recommended doses of each claimed bioactive compound were also highlighted. The latest trends on pre-fermentative methods used to optimize the extraction of bioactive compounds (maceration, decoction, and extraction assisted by supercritical fluids, microwave, ultrasound, pulsed electric fields, high pressure homogenization, or enzymes) are critically assessed. As such, optimized fermentation processes and post-fermentative operations, reviewed in an industrial scale-up, can prolong the shelf life and the quality of fermented fruit beverages.