The objectives of this research were to study the effect of UV irradiation on quality characteristics of mango juice during cold storage. Mango juice exposed to UV radiation was also used to determine zero-order and first-order kinetic models of microbial (total plate count, yeast and mold count, and Escherichia coli) reduction. According to the microbiological results, UV light at 120 J/cm2 caused a 5.19 log reduction. It was found that microbial inactivation of all tested microorganisms followed first-order kinetic model. The treatments did not differ significantly in terms of the quality metrics. L*, b*, pH, total soluble solid, total phenolic compound, total flavonoid content, and antioxidant activity as measured by the DPPH and FRAP assay all tended to decline during storage at 4 °C, whereas a*, ∆E, titratable acidity, total plate count, yeast and mold count, as well as the total plate count, had an increasing trend. During storage at 4 °C, UV irradiation increased the shelf life of mango juice by about 14 days compared to the control sample. In conclusion, this study demonstrated the potential of UV treatment as an alternative to thermal pasteurization for preserving mango juice quality and safety while also prolonging shelf life.
Mangifera , Pasteurization , Pasteurization/methods , Ultraviolet Rays , Saccharomyces cerevisiae/radiation effects , Antioxidants/analysis
This study aimed to investigate the effectiveness of dimethyl dicarbonate (DMDC) at various concentrations (0-250 ppm) in inhibiting the growth of Escherichia coli TISTR 117 and spoilage microbes in passion fruit juice (PFJ) and its impact on the physicochemical and antioxidant quality of the juice during refrigerated storage. The highest log reduction in the total viable count, yeast/molds and E. coli was attained in PFJ samples with 250 ppm of DMDC (p ≤ 0.05) added. Microbial growth inhibition by DMDC followed the first-order kinetic model with a coefficient of determination (R2) and inhibition constants (k) ranging from 0.98 to 0.99 and 0.022 to 0.042, respectively. DMDC at 0-250 ppm showed an insignificant effect on pH, °Brix, color (L*, a*, b*), ascorbic acid, total phenolic compound (TPC), total flavonoid content, and antioxidant activity (DPPH, FRAP) (p > 0.05). Control (untreated PFJ), DMDC-250 ppm, and pasteurized (15 s at 72 °C) samples were subjected to 27 days of cold storage at 4 °C. A decreasing trend in pH, total soluble solid, ascorbic acid content, DPPH and FRAP values were observed in all the samples during refrigerated storage. However, the DMDC-250 ppm sample showed a better prospect in physicochemical quality changes compared to the pasteurized and untreated control PFJ samples. ΔE values showed marked changes in the control sample than the DMDC-250 ppm and pasteurized samples at 27 days of storage. Additionally, the total viable count and yeast/mold count were augmented during storage, and an estimated shelf-life of the control, DMDC-250 ppm, and pasteurized samples was approximately 3, 24 and 18 days, respectively. In conclusion, DMDC at 250 ppm could ensure microbial safety without affecting the quality attributes of PFJ during 24 days of storage at 4 °C.
Using clarifying agents is essential in the production of fruit juice. This study utilized gelatin and bentonite as clarifying agents to improve the quality and shelf-life of Indian gooseberry juice (IGBJ). Different treatments were prepared using varying levels of gelatin and bentonite alone or in combination (1.5-2 mg/mL and 1-2 mg/mL, respectively). The untreated IGBJ was used as a control. The results showed the combined treatment of 1.5 mg/mL gelatin and 1 mg/mL bentonite significantly (p ≤ 0.05) improved the transmittance, â³E value, total acidity, vitamin C, and antioxidant activity of the IGBJ sample. During storage for 49 days at 4 °C, the quality changes in the IGBJ were minimal with the use of 1.5 mg/mL gelatin and 1 mg/mL bentonite compared to the control (p > 0.05). The treated samples showed no signs of spoilage bacteria, yeast, or mold during cold storage. The combined use of gelatin and bentonite (1.5 mg/mL gelatin and 1 mg/mL bentonite) was found to effectively preserve the sensory quality, bioactivity, and color properties of IGBJ, thereby extending its shelf-life. Thus, gelatin and bentonite can be used as preferred filtering aids for quality and shelf-life extension in the food industry, as they have synergistic effects.
This study evaluated the efficiency of UV radiation doses (4.68-149.76 J/cm2) and nisin (50-200 ppm) and their combination in comparison with thermal pasteurization on the microbial inhibition kinetics and physicochemical properties of tangerine juice. It was noted that UV-149.76 J/cm2 and nisin (NS) at 200 ppm in conjunction exhibited the highest log reduction in spoilage and pathogenic microbes including Escherichia coli, Lactiplantibacillus plantarum, and Saccharomyces cerevisiae, yeast and molds, and total plate count in tangerine juice. Additionally, the first-order kinetic model provides a better fit for spoilage and pathogenic strains compared with the zero-order model (higher coefficient of determination, R2), particularly for E. coli. UV and NS showed insignificant effects (p > 0.05) on pH, TSS, and TA values compared with pasteurization. However, there were notable differences observed in color analysis, total phenolic compound, total flavonoid content, vitamin C, carotenoid content, and antioxidant activity using DPPH and FRAP assays. The optimized UV + NS samples were subjected to refrigerated storage for 21 days. The results revealed that during the entire storage period, the pH values and the TSS values slightly decreased, and the TA values increased in the treated samples. The UV + NS treatment insignificantly impacted the color properties. The total phenolic, total flavonoid, and carotenoid contents, and vitamin C decreased over time for all sample treatments, whereas the antioxidant properties exhibited varying outcomes, compared with an untreated control and pasteurization. Therefore, UV radiation and nisin (UV-149.76 J/cm2 + NS-200 ppm) in combination could serve as a viable alternative to traditional heat pasteurization of fruit juice during cold storage.
Purple corn kernels were subjected to boiling and steaming times of 5-15 min to extract purple corn milk (PCM). Pasteurized and unpasteurized PCM samples were investigated for changes in anthocyanins, antioxidants, and physicochemical properties. Anthocyanins, total phenolics, antioxidant activity, color and viscosity values showed promising results in pasteurized PCM samples extracted from kernels steamed for 5 min (PPCM-S5) compared to other samples (p ≤ 0.05). Changes in L*, a* and b* values, total phenolics and DPPH activity were lowered in PPCM-S5 samples with higher retention of anthocyanins compared to the PCM extracted from boiled kernels (p ≤ 0.05). PCM extracted from 5 min steamed kernels fortified with 4% sucrose (PCM5-S4) after pasteurization revealed the lowest changes in color, pH, total soluble solid and viscosity during 12 days of storage at 4 °C compared to the unpasteurized PCM without sucrose and pasteurized PCM fortified with 6% sucrose. Additionally, pasteurized PCM5-S4 samples marked the highest anthocyanins, total phenolics and antioxidant activity during storage. Microbial load was lowest in pasteurized PCM5-S4 samples stored at 4 °C for 12 days. However, coliforms, yeast or mold and Escherichia coli were not present in the thermally processed PCM samples. The highest sensory scores were obtained in PCM5-S4 at day 12 of storage compared to PCM without any treatment. Therefore, pasteurized PCM extracted from 5 min steamed purple corn kernels retained bioactivity along with 4% sucrose fortification resulted in higher sensory acceptability. As a consequence the shelf-life of PCM5-S4 sample was extended up to 12 days at 4 °C.
In this study, the extraction of cocoa shell powder (CSP) was optimized, and the optimized extracts were spray-dried for encapsulation purposes. Temperature (45−65 °C), extraction time (30−60 min), and ethanol concentration (60−100%) were the extraction parameters. The response surface methodology analysis revealed that the model was significant (p ≤ 0.05) in interactions between all variables (total phenolic compound, total flavonoid content, and antioxidant activity as measured by 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP assays), with a lack of fit test for the model being insignificant (p > 0.05). Temperature (55 °C), time (45 min), and ethanol concentration (60%) were found to be the optimal extraction conditions. For spray-drying encapsulation, some quality metrics (e.g., water solubility, water activity) were insignificant (p > 0.05). The microcapsules were found to be spherical in shape using a scanning electron microscope. Thermogravimetric and differential thermogravimetric measurements of the microcapsules revealed nearly identical results. The gum arabic + maltodextrin microcapsule (GMM) showed potential antibacterial (zone of inhibition: 11.50 mm; lower minimum inhibitory concentration: 1.50 mg/mL) and antioxidant (DPPH: 1063 mM trolox/100g dry wt.) activities (p ≤ 0.05). In conclusion, the microcapsules in this study, particularly GMM, are promising antioxidant and antibacterial agents to be fortified as functional food ingredients for the production of nutraceutical foods with health-promoting properties.
This study aimed to investigate the preparation of soy protein isolated (SPI) cutlery incorporated with 5-20% (w/w) crude morning glory stem fiber (MGSF). SPI cutlery samples without and with MGSF were subjected to hydraulic hot press molding at 160 °C for 5 min pressing time. SPI with 5% MGSF showed decreased lightness values compared to the control SPI (without MGSF) (p < 0.05). Flexural modulus attained in SPI with 5% MGSF was higher and subsequently showed decreases in impact strength and compression load compared to the control SPI (p < 0.05). SPI with 5% MGSF sample showed slightly lower water absorption followed by decreases in degree of swelling and solubility with that of the control SPI (p < 0.05). Micrographs revealed a 5% MGSF formed uniform matrix with SPI in comparison to the control and other treatments that showed cracks with the increased fiber addition. Additionally, stiffness decreased with the addition of 5% MGSF to SPI thereby increasing deflection in comparison to the control SPI and other treatments. Thus, SPI cutlery added with 5% MGSF potentially retained the physical and mechanical properties of edible and biodegradable cutlery for food applications.
Cellulose is an abundant component of the plant biomass in agricultural waste valorization that may be exploited to mitigate the excessive use of synthetic non-biodegradable materials. This work aimed to investigate the cellulose utilized by alkaline extraction with a prior bleaching process from rice straw, corncob, Phulae pineapple leaves, and Phulae pineapple peels. The bleaching and alkaline extraction process was performed using 1.4% acidified sodium chlorite (NaClO2) and 5% potassium hydroxide (KOH) in all the samples. All the samples, without and with the alkaline process, were characterized for their physico-chemical, microstructure, thermal properties and compared to commercial cellulose (COM-C). The extraction yield was the highest in alkaline-extracted cellulose from the corncob (AE-CCC) sample (p < 0.05), compared to the other alkaline-treated samples. The undesired components, including mineral, lignin, and hemicellulose, were lowest in the AE-CCC sample (p < 0.05), compared to raw and alkaline-treated samples. The microstructure displayed the flaky AE-CCC structure that showed a similar visibility in terms of morphology with that of the alkaline-treated pineapple peel cellulose (AE-PPC) and COM-C samples compared to other alkaline-treated samples with a fibrous structure. Fourier Transform Infrared (FTIR) and X-ray Diffraction (XRD) of AE-CCC samples showed the lowest amorphous regions, possibly due to the elimination of hemicellulose and lignin during bleaching and alkaline treatment. The highest crystallinity index obtained in the AE-CCC sample showed a close resemblance with the COM-C sample. Additionally, the AE-CCC sample showed the highest thermal stability, as evidenced by its higher Tonset (334.64 °C), and Tmax (364.67 °C) compared to the COM-C and alkaline-treated samples. Therefore, agricultural wastes after harvesting in the Chiang Rai province of Thailand may be subjected to an alkaline process with a prior bleaching process to yield a higher cellulose content that is free of impurities. Thus, the extracted cellulose could be used as an efficient, eco-friendly, and biodegradable material for packaging applications.
Chitosan is a biopolymer known for its rapid biodegradability and film-forming properties. This research aimed to synthesize and characterize chitosan films loaded with cashew leaf extract (CLE) obtained from immature and mature cashew leaves via aqueous and 70% ethanolic extraction methods. Freeze-dried CLE samples were dissolved in 50% dimethyl sulfoxide for in vitro analysis and chitosan film preparation. The total phenolic content of mature cashew leaves extracted in ethanol (MECLE) showed higher free radicle scavenging activity by a 2,2-diphenyl-1-picrylhydrazyl assay than the other extracts (p < 0.05). MECLE displayed a lower minimal inhibitory concentration, minimum fungal concentration, and higher zone of inhibition against Aspergillus niger compared to the other treatments (p < 0.05). Film-forming solutions were prepared using 2% chitosan, 2% chitosan with 5% mature cashew leaves extracted in deionized water (MACLE) (w/v), and 2% chitosan with 5% MECLE (w/v), respectively, to cast films. Of these, 2% chitosan (CH) with 5% MECLE (CH-MECLE-5) displayed the highest thickness and water vapor transmission rate, water vapor permeability, and oxygen transmission rate when compared to other film samples (p < 0.05). The CH-MECLE-5 film showed the highest inhibition zone of A. niger compared to the control and treated films (p < 0.05). The lightness (L*) of the CH-MECLE-5 film decreased with increment in b* values, which represented the yellow color of the film. In addition, two-photon microscopy revealed a uniform distribution via the auto-fluorescent 3D structure of MECLE in the CH-MECLE-5 film. Therefore, chitosan combined with 5% MECLE may be a potential bioactive and eco-friendly packaging film.
Fungal growth in table grapes (Vitis vinifera cv. beauty seedless) is triggered by Botrytis cinerea, Penicillium sp., Aspergillus sp., and Rhizopus stolonifera during post-harvest storage. Due to the safety aspects, this research aimed to develop antifungal packaging embedded with essential oils (EOs) to alleviate the fungal decay of table grapes (TG). The various levels of EOs (0.5-5%, v/v) from clove, cinnamon, thyme, peppermint, lemon, bergamot, ginger, spearmint, and lemongrass were tested against Aspergillus sp. The results attained in radial growth, disk diffusion method, minimal inhibitory concentration, and minimal fungicidal concentration revealed that 1% clove essential oil (CEO) showed higher efficacy against Aspergillus sp. compared to the untreated control and other treatments. CEO at the 1% level exhibited a pleasant odor intensity in TG than the other EOs. The active polyvinyl alcohol (7% PVA) film with 1% CEO resulted in lower weight loss, disease severity, and TG berry drop than the control and other treated samples. Additionally, the acceptance score in the TG sample wrapped with a PVA film containing 1% CEO was augmented. Therefore, the PVA film with 1% CEO retarded the fungal growth and prolonged the shelf life of TG during storage of 21 days at 13 °C and 75% relative humidity (RH).
The effects of in-bag dielectric barrier discharge high voltage cold plasma (IB-DBD-HVCP) on myofibrillar protein isolate (MPI) from Asian sea bass (ASB) and its impact on the physiochemical and gelling properties of MPI gels were elucidated. A mixture of argon (90%) and oxygen (10%) was used for generating IB-DBD-HVCP. MPI was subjected to IB-DBD-HVCP for varying times (5-15 min). Total carbonyl content was increased, while total sulfhydryl content was decreased in MPI, especially with augmenting treatment time (TT) (p < 0.05). Surface hydrophobicity initially increased when IB-DBD-HVCP TT of 5 min (DBD-HVCP5) was implemented, followed by subsequent decrease with increasing TT. Based on gel electrophoresis, lower actin and myosin heavy chain (MHC) band intensities were found for MPI subjected to IB-DBD-HVCP, particularly when a TT longer than 10 min was used, compared to those of the control. Gel made from DBD-HVCP5 had higher breaking force, deformation, and highest G' value compared to others. A more ordered and fibrous network was found in DBD-HVCP5 treated gel. Therefore, IB-DBD-HVCP treatment, particularly for 5 min, enhanced cross-linking of proteins in ASB myofibrillar proteins, which resulted in the improved gel elasticity and strength.
Ethanolic guava leaf extract (EGLE) without chlorophyll removal (GLE-C) and those with chlorophyll removal using sedimentation process (GLE-S) or dechlorophyllization using chloroform (GLE-Ch) were prepared. Antibacterial and anti-melanosis properties of all extracts were examined. All extracts showed promising antibacterial properties, polyphenoloxidase inhibitory activity and copper chelating activity. These activities were highest in GLE-S (P < 0.05). Piceatannol 4'-galloylglucoside, epicatechin, 8-hydroxyluteolin 8-sulfate, quercetin 3-(2''-galloyl-alpha-l-arabinopyranoside), and aclurin 3-C-(6''-p-hydroxybenzoyl-glucoside) were dominant in GLE-S. When Pacific white shrimp were treated with GLE-S at different concentrations (0.5 and 1%), the quality changes were monitored compared to those treated with 1.25% sodium metabisulphite (SMS-1.25) and the control (without any treatment) during 12 days of storage at 4 °C. Changes in microbial and chemical qualities were lower in shrimps treated with GLE-S solution as compared to others. Therefore, melanosis and quality deterioration were effectively reduced by pretreating shrimps in GLE-S before refrigerated storage.
Anti-Bacterial Agents/chemistry , Chlorophyll/isolation & purification , Food Storage/methods , Penaeidae/chemistry , Psidium/chemistry , Seafood/analysis , Animals , Anti-Bacterial Agents/pharmacology , Chlorophyll/chemistry , Food Microbiology , Gram-Negative Bacteria/drug effects , Gram-Positive Bacteria/drug effects , Microbial Sensitivity Tests , Penaeidae/metabolism , Phenol/chemistry , Plant Extracts/chemistry , Plant Extracts/pharmacology , Plant Leaves/chemistry , Plant Leaves/metabolism , Psidium/metabolism , Seafood/microbiology
Inhibition of Pacific white shrimp polyphenoloxidase (PPO) with Chamuang leaf extract (CLE) was studied. CLE was rich in polyphenolic glycosides, in which chrysoeriol 6-C-glucoside-8-C-arabinopyranoside and 2-feruloyl-l-sinapoylgentiobiose were dominant. It also contained organic acids including hydroxycitric acid and oxalosuccinic acid. CLE with copper chelation activity could inhibit PPO in a dose dependent manner. Shrimp treated with 1% CLE had the lower melanosis score than 1.25% sodium metabisulfite (SMS) treated shrimp and the control throughout the refrigerated storage of 12â¯days at 4⯰C (Pâ¯<â¯0.05). Lower total volatile base (TVB) and thiobarbituric acid reactive substances (TBARS) were detected in shrimp treated with 1% CLE, compared to others (Pâ¯<â¯0.05). Lower counts of mesophile, psychrophile, Pseudomonas, Enterobacteriaceae and H2S-producing bacteria were obtained with 1% CLE treatment than the control and SMS treated sample during entire storage. Thus, soaking of shrimps in 1% CLE solution effectively reduced melanosis and quality deterioration.
Garcinia/chemistry , Penaeidae/chemistry , Plant Extracts/pharmacology , Seafood/standards , Animals , Catechol Oxidase , Refrigeration
BACKGROUND: The aim of this study was to assess the pattern of periurethral bacterial flora in uncircumcised boys and to evaluate the effect of circumcision on alteration of periurethral uropathogenic bacterial flora. MATERIALS AND METHODS: Pattern of periurethral bacterial flora before and after circumcision was studied prospectively in 124 boys. The results were analysed to compare change in bacterial colonisation before and after circumcision. RESULTS: The age range was 6 weeks to 96 months. Most (94.3%) of the boys had religious indication and 5.7% had medical indication for circumcision. E. coli, Proteus and Klebsiella were most common periurethral bacterial flora in uncircumcised subjects. Coagulase-negative staphylococcus and Staphylococcus aureus was most common periurethral bacterial flora in circumcised subjects. In 66.1% of circumcised subjects, no bacteria were grown from periurethral region. CONCLUSION: We conclude that presence of prepuce is associated with great quantity of periurethral bacteria, greater likelihood of the presence of high concentration of uropathogens and high incidence of urinary tract infection (UTI). This study provides circumstantial evidence supporting the idea that early circumcision may be beneficial for prevention of UTI.
Circumcision, Male , Urethra/microbiology , Urinary Tract Infections/epidemiology , Humans , Incidence , Infant , Male , Urinary Tract Infections/prevention & control
