Reduction In Ascorbic Acid Content Research Articles

Effects of semi‐rigid plastic tray geometry on quality characteristics of a retort food simulant

AbstractThe present study aims to investigate how the geometric shapes of semi‐rigid plastic trays impact the quality characteristics of a retort processed food simulant. Initially, oval, triangular, rectangular, and round‐shaped plastic trays with a tomato‐based food simulant were subjected to retorting at rotational speeds of 6 and 11 revolutions per minute (RPM), and various food quality attributes were assessed. At 6 RPM, triangle‐shaped and round‐shaped trays exhibited a significantly greater reduction (p < 0.05) in ascorbic acid (AA) content compared to oval or rectangular‐shaped trays. Furthermore, there were no significant differences (p > 0.05) in lycopene and hydroxymethylfurfural (HMF) content change from control among the different tray shapes at 6 RPM. However, hexanal content change was found to be greater in rectangular‐shaped trays than in oval‐shaped trays, while no significant difference was observed between triangular and round‐shaped trays. Both triangular and rectangular‐shaped trays showed a substantially greater (p < 0.05) total color difference (ΔE) compared to other shapes. This data suggests the presence of a temperature gradient in the food simulant influenced by the tray's shape. At 11 RPM, oval and round‐shaped trays showed a significant reduction in AA content, while rectangular‐shaped trays exhibited higher lycopene levels compared to oval and round trays. There was an increase in HMF response from control across all tray shapes; however, differentiation between shapes was not significant (p > 0.05), while both triangle and round‐shaped trays had elevated hexanal content as compared to oval‐shaped trays (p < 0.05). Oval, round, and triangle‐shaped trays all exhibited a greater ΔE than rectangular‐shaped trays. In summary, oval and round‐shaped trays exhibited a more pronounced change in AA content at 11 RPM, indicating a faster temperature equilibration. In contrast, triangle and rectangular‐shaped trays displayed elevated total color differences at 6 RPM, which may suggest the presence of a temperature gradient leading to uneven heating due to their respective shapes.Practical applicationsThis information would be applicable to new food products designed for thermal treatment in which the packaging shape could be manipulated to not only fit infrastructure requirements (packaging equipment, processing equipment, distribution devices) but also help support heat penetration at an optimal rate. Depending on product type and makeup, this approach may hold some value to the product developer whose product will be packaged in semi‐rigid plastic containers.

Augmenting pomelo juice quality through membrane-based clarification and bioactive compounds recovery

The presence of impurities, microorganisms, enzymes, suspended solids, and impurities in unclarified pomelo juice negatively affected the quality and shelf-life of the product in the food industry. The objective of this study focuses on the clarification of fresh pomelo juice using an ultrafiltration (UF) process. The study examined the influence of the operating pressure (OP) on the various quality attributes of pomelo juice, such as pH, total soluble solids (TSS), turbidity, color, total phenolic content (TPC), ascorbic acid content (AAC) and fouling mechanisms and permeate flux (J) behavior. To perform the clarification of pomelo juice, a 100 kDa membrane (polymeric) was used in a dead-end system, and the process was carried out in batch mode at OP values of 1.0, 1.5, 2.0, 2.5 and 3.0 bar. The findings revealed that increasing OP led to higher flux during ultrafiltration with limiting pressure (P lim). The limiting pressure (P lim) was anticipated to be beyond 3.0 bar due to the enzymatic pretreatment. The primary fouling mechanism during the clarification process was total pore blocking. After filtration, the resulting juice showed a significant reduction in turbidity of over 97%, while TSS was lowered by 7–17% compared to fresh juice. The pomelo juice was efficiently clarified while the pH remained stable at ∼3.8. The clarified juice showed a minor decline of 10.1–13.9% in TPC and a 10.8–16.7% reduction in AAC compared to the fresh unclarified juice. In conclusion, a pressure of 3.0 bar is recommended for conducting the ultrafiltration process in order to attain desirable flux behavior and optimum properties of the juice.

Effect of cooking methods on the nutritional quality of selected vegetables at Sylhet City

The study was carried out to analyze the impacts of boiling, steaming, and microwave cooking on the physicochemical properties, the content of bioactive compounds, and boiling effect on mineral and heavy metal content of six widely consumed vegetables in Bangladesh's north-eastern region. In comparison to raw, boiled, and microwave-cooked vegetables, those that are steam-cooked retain a higher percentage of β-carotene with the exception of carrots. Boiling vegetables led to the most substantial reduction in ascorbic acid content (from 9.83 % to 70.88 %), with spinach experiencing the greatest decline. In contrast, microwaving had the mildest effect on ascorbic acid, preserving over 90 % of the initial content. The decrease in carotene content may be associated with color changes (decreasing greenness and increasing hue angle) in the chosen vegetables. The colorimeter shows the L* value (lightness/darkness) of all cooked vegetables significantly decreased. In terms of total polyphenol content (TPC) and total flavonoid content (TFC), boiling had a higher negative effect on most vegetables than the other two cooking methods, with losses of up to 70.3 % and 82.27 %, respectively. All cooked vegetables, with the exception of carrot and microwave pumpkin, had substantial reductions in free radicals scavenging activity, with losses ranging from 8.48 % to 56.73 %. In comparison to raw vegetables, boiled vegetables significantly lost minerals like potassium (K), magnesium (Mg), zinc (Zn), copper (Cu), and manganese (Mn). On the other hand, the calcium (Ca) and iron (Fe) content of all cooked vegetables, except for carrots and peas, exhibited an increase, ranging from 6 to 17 % and 6–12 %, respectively. The Cr concentration in all vegetables and the Zn, Fe, Mn, and Cd content in the spinach sample was higher than the FAO/WHO recommended maximum permissible level (MPL), whereas the accumulation of Cu and Ni content was lower in all vegetables. In conclusion, this study demonstrated that microwaving was the most effective method for retaining the nutritional value of vegetables, while steaming had a moderate impact.

Performance evaluation of different grown ber (Ziziphus mauritiana) cultivars under low-temperature storage

ABSTRACT Ber (Ziziphus mauritiana), also known as “Chinese date” or “jujube,” belongs to the Rhamnaceae family. The current research was designed to assess the effect of storage temperatures (5°C and 15°C) on ascorbic acid content, reducing sugar content, and titratable acidity of four ber (Z. mauritiana) varieties, i.e. Karela, Aakash, Pak white, and Dil-Bahar. For this purpose, fresh ber (Z. mauritiana) varieties were acquired from the Regional Agriculture Research Institute (RARI), Bahawalpur. In the first phase, these ber (Z. mauritiana) varieties were subjected to proximate analysis of reducing sugar contents, titratable acidity, antioxidant activity, and total phenolic contents. Maximum total phenolic content (144.38 ± 0.03 mgGAE/100 g) and antioxidant activity (39 ± 0.06%) were observed in Dil-Bahar variety. In the second phase, stored ber (Z. mauritiana) varieties were subjected to a storage study at 0, 7th, and 14th days for comparative evaluation based on titratable acidity, reducing sugar content, and ascorbic acid content. The results showed that the fruits stored at 5°C showed a maintained level of ascorbic acid content (31.26 ± 0.02 mg/100 g), reducing sugars (41.25 ± 0.02%), and titratable acidity (3.36 ± 0.01%) in Karela. On the contrary, Karela stored at 15°C showed a reduction in ascorbic acid content (28.12 ± 0.02 mg/100 g) and titratable acidity (1.21 ± 0.01%) and an increase in reduced sugar content (46.48 ± 0.03%). Moreover, Dil-Bahar variety showed higher ascorbic acid content (51.69 ± 0.05 mg/100 g), titratable acidity (3.51 ± 0.02%), and reducing sugar content (33.29 ± 0.01%) at 5°C. It was concluded that cultivars showed the best results at low storage temperatures of 5°C.

Evaluating the effects of different processing methods on the nutritional quality of bovine milk

Milk is a universal food that is widely consumed around the world irrespective of age. It has a complex matrix consisting of proteins, carbohydrates, minerals, vitamins, and enzymes that have successfully retained the interest of researchers as yet. The aim of the study was to evaluate the effect of low-temperature long-time (LTLT), ultraviolet light (UV), and ultrasound (US) treatments on physicochemical properties, microbial count, and fatty acid profiling of three types of bovine milk – Country (C), Jersey (J), and Holstein Friesian (HF). The study was conducted in southern India, where these three types of milk are commonly consumed. It was found that no significant (p ˂ 0.05) differences in the proximate composition of milk samples subjected to different treatments compared to untreated milk. However, LTLT treatment resulted in a reduction in ascorbic acid content and significant changes in antioxidant activity and lactose content. LTLT treatment was also able to kill the pathogenic bacteria E. coli, whereas UV and US treatment only showed a notable reduction in the E. coli count. Fatty acid profiling of the treated milk samples was done using GC/MS, and Fourier Transform Infrared Spectroscopy (FTIR) was performed to study the types of chemical bonds present. The results showed that non-thermal treatments (UV and US) were able to sustain the chemical characteristics of milk and had potential for implementation in the dairy industry. Overall, the study highlights the potential benefits of non-thermal treatments such as UV and US in maintaining the chemical properties of milk and reducing pathogenic bacteria count. The findings could be useful in the dairy industry to ensure the safety and quality of milk.

Efficacy of flaxseed protein-based edible coatings on the quality of whole guava (Psidium guajava) during storage

The objective of this study was to investigate the influence of flaxseed protein isolate coating solutions (FPC1 & FPC2) comprising of flaxseed protein (3% w v-1 and 5% w v-1) enriched with 20% glycerol (on a protein isolate basis), tween-40 (20% w v-1) and 20% guar gum on the quality attributes of guava fruit stored under the controlled conditions of 65% RH and 20℃ temperature. The use of edible coatings notably delayed the spoilage of guava, which was examined by studying the quality parameters associated with the ripening of whole guavas. There was retardation of oxidative browning, polyphenol contents and reduction in ascorbic acid content as compared to control samples. Moreover, coating treatments predominately decrease the total plate counts, reflected in the Colony-forming unit (CFU g-1) and significantly (p < 0.05) decrease the water loss. The non-coated samples of guavas showed a consistent reduction in lightness (L*) values when confronted with coated fruits. Sensory scores for taste, colour, texture, flavour and overall acceptability were higher for all the coated samples than control (non-coated) samples of guavas. Thus, the flaxseed protein isolate-based coatings have shown the potential in protecting the quality attributes of guavas and enhance the shelf life up to 16 days.

Possibility of using leaf extracts of tree-of-heaven (Ailanthus altissima (Mill.) Swingle) for the postharvest quality preservation of fresh apricot fruits

This study was conducted to test the possibility of using leaf extracts of invasive weed tree-of-heaven (Ailanthus altissima (Mill.) Swingle) for the postharvest quality preservation of apricot (cv. ‘Şalak’) fruits. Two different doses of A. altissima leaf extracts (0.5% and 2.5%) with and without supplements (0.1% g Arabic gum, 0.05% citric acid, 0.05% potassium sorbate and 0.05% ascorbic acid) were tested. Results showed that the extracts of A. altissima leaves have strong ability to prevent weight loss, reduce decay incidence, protect visual quality, delay the occurrence of chilling injury, keep fruit firmness and delay the reduction in ascorbic acid content.

Microwave pre‐treatment for vacuum drying of orange slices: Drying characteristics, rehydration capacity and quality properties

AbstractMicrowave pre‐treatment for vacuum drying is a promising method in order to enhance heat and mass transfer rate. In this study, the influences of microwave pre‐treatment (90 W 30 min) on vacuum drying conducted at different combinations of drying temperature and absolute pressure (60, 70, and 80°C with 15 and 30 kPa) were investigated by evaluating the drying characteristics, rehydration capacity, and some quality attributes of orange slices. The vacuum drying treatments were carried out both with (MWVD) and without the microwave‐pretreatment (VD) at the same temperature and absolute pressure combinations. It was revealed that application of MWVD shortened the drying time of orange slices while increasing drying rate, effective moisture diffusivity and rehydration capacity. Six different semi‐theoretical mathematical models were applied, and Page, Modified Page, Logarithmic, and Lewis models were best fitted to experimental data of orange slices. It was observed that, among the different drying conditions applied in the scope of the study, VD at 80°C–15 kPa caused lowest color change (ΔE) that indicates the difference between the dried and fresh orange slices. All drying treatments caused a reduction in ascorbic acid content (AAC) (56.24–59.34%), total phenolic content (TPC) (15.92–55.79%) and total antioxidant capacity (TAC) (6.05–35.18%, 21.03–42.28%, and 54.76–69.07% for DPPH, FRAP, and CUPRAC assays, respectively) of orange slices. When MWVD and VD were compared, it was observed that MWVD caused less decrease in TPC and more in AAC and TAC. In conclusion, MWVD method is suggested as the more effective method providing lower drying time, faster drying rate, and better quality parameters of the product.Practical applicationsOrange including various nutrients with health beneficial effects is a perishable fruit. Therefore it is processed in to frozen, dried, canned, jam and fruit juice forms in order to increase its shelf life. Especially in seasons with overproduction, orange can be processed into dried form, and it can be turned into an alternative healthy snack with increased commercial value. In this research, drying characteristics of orange slices by microwave pre‐treated for vacuum drying were assessed with mathematical modeling. Drying conditions affected rehydration capacity, total phenolic content (TPC), total antioxidant capacity (TAC), ascorbic acid content (AAC) and color values of orange slices. Based on those outcomes, the optimum process conditions for an industrial drying application can be designed to enhance heat and mass transfer rate and to improve quality attributes of the product.

Effect of hot water treatment of seeds on quality indicators of alfalfa sprouts

The aim of this study was to evaluate the effect of soaking seeds in hot water on the content of selected bioactive compounds in alfalfa sprouts. Temperature and time regimes were: 85 °C, for 10 and 40 s; 90 °C and 100 °C, for 10 s. Sprouts were examined for the contents of ascorbic acid, chlorophylls a and b, α- and β-carotene, neoxanthin, violaxanthin, lutein and total phenolics. In most cases, the treatment applied had no significant effect on the contents of lutein, violaxanthin, neoxanthin, β-carotene and total phenolics. However, disinfection at 100 °C caused a significant reduction in ascorbic acid content, an increase in total phenolic content and a rise in the proportion of cotyledons in the mass of sprouts. The treatment variants applied did not significantly affect the total chlorophyll content in cotyledons. This study revealed that seed treatment with hot water may, depending on the applied parameters, affect sprout morphology, ascorbic acid content and total phenolic content.

Application of edible coatings and repetitive pulsed light for shelf life extension of fresh-cut cantaloupe (Cucumis melo L. reticulatus cv. Glamour)

The objective of this study was to investigate the effects of edible coatings combined with repetitive pulsed light (RPL) treatment on microbiological stability, quality and physicochemical changes of fresh-cut cantaloupes during storage at 4±1°C. Fresh-cut cantaloupes were coated with various coating materials. The coated fresh-cut cantaloupes were packed in polypropylene bag and exposed to RPL treatment with a fluence of 0.9Jcm−2 every 48h up to 28d of storage at 4±1°C. The microbiological quality, headspace gas composition, physical quality (firmness, fluid loss and colour), chemical quality (pH, titratable acidity, total soluble solids, total phenolic content and ascorbic acid content) and coating homogeneity and adherence of these fresh-cut cantaloupes were determined. The combination of pectin, alginate and gellan coatings with RPL treatment was effective to reduce fluid loss and retain firmness of fresh-cut cantaloupes compared to control samples while maintaining the desired headspace gas composition for fresh-cut cantaloupe throughout storage. Chitosan-based coating enhanced the microbiological quality of fresh-cut cantaloupes but increased its fluid loss and reduction of ascorbic acid content. Colour, pH, titratable acidity, total soluble solids and total phenolic content were maintained throughout the storage for coated fresh-cut cantaloupes treated with RPL. In conclusion, a combination of alginate and RPL treatment was the most effective treatment condition to extend the shelf life of fresh-cut cantaloupes by maintaining microbiological quality up to 28d with significantly reduced fluid loss and enhanced firmness compared to samples treated with RPL alone. Alginate coating adhered well to the surfaces of fresh-cut cantaloupes and retained its physicochemical and nutritional quality when combined with RPL.

Nutritional Quality of Field-grown Tomato Fruit as Affected by Grafting with Interspecific Hybrid Rootstocks

In this study, the effects of grafting with interspecific hybrid rootstocks on field-grown tomato fruit quality were evaluated over a 2-year period. Fruit quality attributes from determinate ‘Florida 47’ tomato plants grafted onto either ‘Beaufort’ or ‘Multifort’ rootstocks were compared with those from non- and self-grafted controls. Grafted plants had higher fruit yields than non- and self-grafted plants, and increased production of marketable fruit by ≈41%. The increased yield was accompanied by few major differences in nutritional quality attributes measured for these fruit. Although grafting with the interspecific rootstocks led to consistently small, but significant increases of fruit moisture (≈0.6%), flavor attributes such as total titratable acidity (TTA) and the ratio of soluble solids content (SSC) to TTA were not significantly altered. Among the antioxidants evaluated, ascorbic acid concentration was reduced by 22% in fruit from grafted plants, but significant effects were not evident for either total phenolics or antioxidant capacity as assayed by oxygen radical absorbance capacity (ORAC). Levels of carotenoids (lycopene, β-carotene, and lutein) were similar in fruit from grafted plants with hybrid rootstocks compared with non- and self-grafted controls. Overall, the seasonal differences outweighed the grafting effects on fruit quality attributes. This study showed that grafting with interspecific hybrid rootstocks could be an effective horticultural technique for enhancing fruit yield of tomato plants. Despite the modest reduction in ascorbic acid content associated with the use of these rootstocks, grafting did not cause major negative impacts on fruit composition or nutritional quality of fresh-market tomatoes.

Effect of High Hydrostatic Pressure on Ascorbic Acid, Phenolic Compounds and Antioxidant Activity of Pera Rio Orange Juice

Orange juice is the most popular juice in the world, representing an important source of bioactive compounds in diet. High hydrostatic pressure (HHP) is an alternative technology that does not use high temperature, being able to preserve flavor and nutritional characteristics of the juice. The influence of HHP treatment conditions, pressure (100-600 MPa), temperature (30- 60°C) and time (30-360 s), on ascorbic acid, phenolic compounds and antioxidant activity of orange juice was investigated using response surface methodology. Analysis of variance showed that quadratic polynomial models fitted well with the experimental data for ascorbic acid (R²=0.92, p<0.01) and antioxidant activity using the ABTS*+ assay (R²=0.91, p<0.01). The increase in time and temperature of HHP treatment promoted the reduction of ascorbic acid content and antioxidant activity in orange juice. HHP treatment reduced the ascorbic acid content and antioxidant activity of orange juice. The HHP treatment conditions of 100 to 250 MPa, 30 to 40°C and 30 to 125 s were able to produce orange juice with more than 70% of the initial ascorbic acid content and 80% of the antioxidant activity.

Effect of NaCl salt stress on the proline and ascorbic acid content of isabgol(Plantago ovataForsk.) genotypes

Biochemical changes in leaves of isabgol (Plantago ovata Forsk.) genotypes viz., GI-2, HI-96, PB-80 and HI-5 were studied under salt stress at different EC levels viz., control (without salt), 5 and 10 dS/m of nutrient supplemented NaCl salt solutions in sand filled polythene bags. The results revealed a significant increase in proline with increase of salt stress. Maximum accumulation of proline was found in the genotype GI-2, while minimum in the genotype PB-80. Ascorbic acid content significantly declined with increasing EC levels. Reduction in ascorbic acid content was maximum in the genotype PB-80 and minimum in GI-2. These findings indicate higher tolerance of genotype GI-2 and higher sensitivity of the genotype PB-80 to salt stress among all the genotypes studied.

Cold storage of peaches cv. Aurora grown in the Zona da Mata Mineira, Minas Gerais State, Brazil

This study aimed to evaluate the postharvest behavior of peach cv. Aurora 1 harvested in the Zona da Mata region of Minas Gerais in two ripening stages and kept under different storage temperatures. Fruits on mid-ripe and fully ripe stages were stored at three temperatures: 5.6 ± 1.57 °C and 72.8 ± 3.8% RH; 10.4 ± 0.5 °C and 95.8 ± 5.5% RH; 21.04 ± 1.63 °C and 96.9 ± 2.6% RH up to 28 storage days (SD) . During storage, fruits stored at 21.04 ± 1.63 °C were evaluated every two days until 8 SD, and every four days for fruits stored at other temperatures. The harvest day was assigned as day zero. The variables evaluated were CO2 production, color of the pericarp and pulp, fresh mass loss, flesh firmness, total soluble solids, titratable acidity, contents of ascorbic acid and carotenoids. The fresh mass loss increased during storage, peaking at 5.6 °C. The reduction in ascorbic acid content was higher in fully ripe fruits at all temperatures. Mid-ripe fruits reached the end of the storage period with better quality. The temperature of 10.4 °C was the most efficient in keeping postharvest quality of peach cv. Aurora 1 harvested in the Zona da Mata region.

Shelf-life and microbiological safety studies of refrigerated petha sweet.

This study was conducted at Indian Institute of Vegetable Research, Varanasi (I.I.V.R.), Uttar Pradesh from 2006 to 2009 for evaluating comparative physico-chemical, microbiological and sensory attributes of crystallized and Kashi petha at refrigerated storage (4 ± 1°C) condition up to 90days. The petha were manufactured using 2 varieties of ash gourd developed at I.I.V.R. i.e.; Kashi Dhawal and Kashi Ujwal, selected based on different parameters suitable for petha sweet preparation. The used packaging materials for storage studies were laminated pouch, low density polyethylene, high density polyethylene. The physiochemical analysis and sensory evaluation were performed at 15days interval upto 90days for storage study in both Kashi Petha and crystallized petha, while microbial observation was recorded up to 90days in crystallized petha and up to 50days Kashi Petha. Physico-chemical analysis exhibited the continuous increase in moisture (25.79-26.80% and 31.68-32.63%) and titratable acidity (0.022-0.029%) and (0.022-0.030%) and reduction in ascorbic acid content (5.50-5.00mg/100g and 5.12-4.84mg/100g), respectively in crystallized and Kashi petha. The increasing trend in microbial population was more pronounced in Kashi petha in comparison to crystallized petha. The spoilage bacteria included Bacillus spp., Staphylococcus spp. and lactic acid bacteria while Aspergillus, Penicillium and Saccharomyces were observed among fungal contaminants. The bacteria, yeast and mold were identified on the basis of cultural, morphological and biochemical characterization with respect to storage period. On the basis of the overall findings of comparative physico-chemical, microbiological and sensory evaluation, 30 and 50days of storage was considered as safe for the consumption of Kashi and crystallized petha, respectively under refrigerated environment (4 ± 1°C).

Desempenho de filmes comestíveis em comparação ao filme de policloreto de vinila na qualidade pós-colheita de mexericas 'Poncã'

O objetivo do trabalho foi avaliar o efeito de diferentes concentrações de fécula de mandioca na vida útil pós-colheita de frutos 'Mexerica Poncã' durante o armazenamento em temperatura ambiente em substituição ao filme de policloreto de vinila (PVC). Os frutos foram imersos em suspensões aquosas de fécula de mandioca a 0; 1; 2 e 3% (m:v) acrescidas de 0,5mL L-1 de óleo mineral Assist (Bayer Cropscience, da empresa Hoechst Schering AgrEvo UK Ltd. - Inglaterra) ou recobertos com PVC de 14µm de espessura, e armazenados a temperatura ambiente. As amostragens foram realizadas no tempo zero (início do experimento) e a cada dois dias, por oito dias. Foram avaliadas a perda de massa fresca, rendimento de suco, sólidos solúveis (SS), acidez titulável (AT), relação SS/AT e teor de ácido ascórbico. A perda de massa fresca aumentou durante o armazenamento, sendo mais acentuada na dose de 2%. A redução no teor de ácido ascórbico foi maior nos frutos recobertos com filme de PVC. A concentração de fécula de mandioca a 1% foi a que proporcionou melhores resultados quanto à manutenção da qualidade físico-química de frutos de 'Mexerica Poncã' durante oito dias de armazenamento.

Comparison of the efficacy of gamma and UV irradiation in sanitization of fresh carrot juice

As there is no pasteurization procedure for the manufacture of fresh vegetable juice, both industry and consumers have sought a method for improving the storage stability and shelf-life of this category of products. In this study, the effects of commercially available, non-thermal pasteurization processes, such as gamma and UV irradiation, were compared for their efficacy in sanitizing fresh carrot juice (FCJ). FCJ was manufactured, packaged, and gamma irradiated with doses of 0, 1, 3, and 5kGy. The manufactured FCJ was also passed through 4 UV light lamps at doses of 3.67, 4.69, and 6.50kGy. The total aerobic bacterial count of the FCJ approached the legal limit (105 CFU/mL) after manufacturing. Both treatments were effective in reducing the number of total aerobic bacteria, and the reduced number was maintained during storage for 7 days. Gamma irradiation was more effective in suppressing microbial growth during storage. When the doses for UV treatment and gamma irradiation were higher, the inactivation effects were higher. The reduction of ascorbic acid content was greater upon gamma irradiation than UV treatment. No difference was found in the contents of flavonoids and polyphenols in FCJ after either treatment. After 3 days of refrigerated storage, the sensory scores of gamma- or UV-irradiated FCJ were superior to those of the control. The results indicate that both non-thermal treatments were effective in improving storage stability and extending shelf-life, but gamma irradiation was slightly better in suppressing microbial growth after treatment.

Development of an optimised papaya pulp nectar using a combination of irradiation and mild heat

Abstract Papaya does not sufficiently maintain desired fresh fruit quality when shipped long distances due to an easily bruised soft skin and a short shelf life. This leads to both a large supply of pulp from unsightly fruit that is never shipped and low sales due to blemished fruit. Unfortunately, traditional preservation methods (pasteurisation) negatively alter papaya’s fresh flavour. Thus to effectively utilise available papaya pulp, processing requires an approach that enables retention of papaya’s natural flavours without excessive heat. Papaya fruit (Carica papaya L., var.’s Rainbow (yellow-fleshed) and SunUp (red-fleshed)) were pulped, diluted, and processed with mild heat (80 °C, 5 min), irradiation (5 kGy or 7.5 kGy) or combinations of both. Irradiation resulted in a significant reduction in ascorbic acid content. Mild heat treatment significantly reduced pectinesterase activity and microbiological viability. Irradiation followed by heat further enhanced destruction of Listeria innocua and Clostridium sporogenes and retained the flavour and a nutritional profile closest to untreated controls. The product was microbiologically safe with acceptable enzyme levels and would be shippable under refrigeration.

Bergamot: A source of natural antioxidants for functionalized fruit juices

Bergamot is a common Italian citrus fruit, cultivated almost exclusively to produce essential oils; the juice is considered a waste product, which represents a serious environmental and economic problem for the industries. The aim of this study was to re-evaluate bergamot juice through its chemical characterization and its use to enrich and fortify fruit juices. To investigate this, apples and apricots were used for the laboratory-scale production of fruit juice, following both the traditional industrial recipe and those with the addition of bergamot juice at 10% or 20%, together with or in order to replace the synthetic additives normally used in the industrial process (ascorbic acid and citric acid). The ascorbic acid content and the antioxidant activity were measured during the different steps of juice production and after storage at 37 °C for 15 days to evaluate juice shelf-life. Apricot and apple juices fortified with bergamot juice showed a significant increase in their antioxidant properties and a decreased reduction in ascorbic acid content after the typical production steps. All of the results obtained support the hypothesis that the addition of bergamot juice to juices preserves their ascorbic acid content from thermal degradation and contributes to enhance the antioxidant activity, ensuring a product much richer in antioxidants and ascorbic acid. A preliminary consumer test encouraged the production of bergamot fortified fruit juices. Finally, this is the first time that isorhoifolin and rutin have been detected in bergamot juice.

Effects of Ionizing Radiation on Sensorial, Chemical, and Microbiological Quality of Frozen Corn and Peas

The effects of irradiation (0, 1.8, and 4.5 kGy) on the quality of frozen corn and peas were investigated during a 12-month period of postirradiation storage at −18°C. Irradiation of frozen corn and peas caused a reduction in ascorbic acid content of both vegetables and a loss of texture in peas but had no significant effects on instrumental color parameters (L*, a*, and b*), carotenoid and chlorophyll content, or antioxidant capacity of corn and peas. Irradiation reduced microbial loads of frozen peas and increased display life at 23°C of thawed peas by preserving the green color, apparently because of slower increases in the population of acid-producing microorganisms in the irradiated samples. Overall, irradiation significantly reduced the microbial load and increased the display life of peas and had minimal detrimental effects on the quality of frozen corn and peas.