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Copyright of Food & Fermentation Industries is the property of Food & Fermentation Industries and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Edible films based on fruit and vegetable purees combined with different food-grade biopolymeric binding agents (e.g., pectin, gelatin, starch, sodium alginate) are recognized as interesting packaging materials that benefit from the physical, mechanical, and barrier properties of biopolymers as well as the sensory and nutritional properties of purees. In the current contribution, edible antioxidant films based on pear juice and pregelatinized cassava starch were developed. In particular, the suitability of using pregelatinized cassava starch for the non-thermal production of these novel edible films was evaluated. In addition, the effects on the films' properties derived from the use of pear juice instead of the complete puree, from the content of juice used, and from the carbohydrate composition associated with the ripening of pears were all studied. The produced films were characterized in terms of their total polyphenol content, water sensitivity, and water barrier, optical, mechanical and antioxidant properties. Results showed that the use of pear juice leads to films with enhanced transparency compared with puree-based films, and that juice concentration and carbohydrate composition associated with the degree of fruit ripeness strongly govern the films' properties. Furthermore, the addition of pregelatinized cassava starch at room temperature discloses a significant and favorable impact on the cohesiveness, lightness, water resistance, and adhesiveness of the pear-juice-based films, which is mainly attributed to the effective interactions established between the starch macromolecules and the juice components. [ABSTRACT FROM AUTHOR]

In this study, ultra–high–pressure sterilization (UHPS) of Xinli No. 7 juice (XL7) was explored and optimized. A challenge to implement UHPS in juice as a full alternative to thermal treatment could be represented by the adoption of a pressure level of up to 500 MPa for 20 min at one cycle followed by the packaging in aseptic conditions. It was found that UHPS and HS treatments could effectively kill the microorganisms in XL7 juice but HS treatment would inevitably lose the nutritional quality in the juice, while UHPS treatment could better maintain the glyconic acid content, functional components, and antioxidant activity and reduce Browning degree and improve the stability of XL7 juice. The deterioration rate of UHPS and HS–treated XL7 juice increased with the increased storage temperature. The predicted shelf life of UHPS and HS–treated XL7 juice was 68 and 41 days at 4 °C, respectively. Collectively, UHPS treatment combined with low–temperature storage might be an effective way to prolong the shelf life of XL7 juice. [ABSTRACT FROM AUTHOR]

Although pear is one of the most preferred fruits globally due to its high nutrient content, its juice products have not received equal consumer acceptability due to their undesirable haziness and turbidity. However, enzymatic treatment of juice has been noted to improve the overall acceptability of juices better than traditional decantation, filtration, and heating methods, which are either expensive or detrimental to the product quality. In this study, pear juice was effectively clarified using partially purified polygalacturonase from an entomopathogenic fungal endophyte Beauveria bassiana SAN01. The optimization of the juice clarification process led to 137% improvement in clarification compared to control, under optimal conditions of 39.37 U/mL enzyme load, 36.87°C temperature and 2.75 h treatment time. Results also showed that the polygalacturonase treatment resulted in a significant decrease in viscosity and an increase in the pseudoplasticity of the pear juice as the rheological data of the juice was observed to fit adequately into the power law model (R 2>0.9). Furthermore, the enzyme-assisted juice clarification was found to reduce browning index (-14.34%) and turbidity (-19.72%) while increasing the reducing sugar content (9.55%). Unlike some conventional juice treatments, the polygalacturonase treatment preserved the antioxidant potential and the total phenolic contents of the pear juice as no significant changes were observed after the treatment. This study thus demonstrates the efficacy of a fungal polygalacturonase in improving pear juice quality as well as the potential applicability of B. bassiana enzymes in the food industry.

Patulin (PAT) is a toxic secondary metabolite produced by certain species of Penicillium sp. and Aspergillus sp. on apples and pears. In this study, we investigated the effects of ascorbic acid and the combination of ascorbic acid and ferrous iron on degradation of PAT in 100% pure pear juice and apple juice using high-performance liquid chromatography UV detector (HPLC-UVD). The addition of 2 different levels of ascorbic acid (143 or 286 μg/mL) into pear juice or apple juice containing 0.08 or 0.4 μg/mL of PAT showed 87.7–100% and 67.3–68.7% of PAT degradation rates, respectively, after 24 h incubation at 25 °C. Moreover, the addition of both ascorbic acid (143 or 286 μg/mL) and ferrous iron (0.033 or 0.11 μmol/mL) into pear juice or apple juice containing the same level of PAT exhibited higher PAT degradation rates (100 and 75–94%, respectively) than the addition of only ascorbic acid after 24 h incubation at 25 °C. Our data demonstrated that ascorbic acid plus ferrous iron as well as ascorbic acid were highly effective on degradation of PAT in pear juice and apple juice and that addition of both ascorbic acid and ferrous iron produced higher PAT degradation rates than addition of only ascorbic acid. [ABSTRACT FROM AUTHOR]

In this study, ultra–high–pressure sterilization (UHPS) of Xinli No. 7 juice (XL7) was explored and optimized. A challenge to implement UHPS in juice as a full alternative to thermal treatment could be represented by the adoption of a pressure level of up to 500 MPa for 20 min at one cycle followed by the packaging in aseptic conditions. It was found that UHPS and HS treatments could effectively kill the microorganisms in XL7 juice but HS treatment would inevitably lose the nutritional quality in the juice, while UHPS treatment could better maintain the glyconic acid content, functional components, and antioxidant activity and reduce Browning degree and improve the stability of XL7 juice. The deterioration rate of UHPS and HS–treated XL7 juice increased with the increased storage temperature. The predicted shelf life of UHPS and HS–treated XL7 juice was 68 and 41 days at 4 °C, respectively. Collectively, UHPS treatment combined with low–temperature storage might be an effective way to prolong the shelf life of XL7 juice.

Copyright of Modern Food Science & Technology is the property of Editorial Office of Modern Food Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Although pear is one of the most preferred fruits globally due to its high nutrient content, its juice products have not received equal consumer acceptability due to their undesirable haziness and turbidity. However, enzymatic treatment of juice has been noted to improve the overall acceptability of juices better than traditional decantation, filtration, and heating methods, which are either expensive or detrimental to the product quality. In this study, pear juice was effectively clarified using partially purified polygalacturonase from an entomopathogenic fungal endophyte Beauveria bassiana SAN01. The optimization of the juice clarification process led to 137% improvement in clarification compared to control, under optimal conditions of 39.37 U/mL enzyme load, 36.87°C temperature and 2.75 h treatment time. Results also showed that the polygalacturonase treatment resulted in a significant decrease in viscosity and an increase in the pseudoplasticity of the pear juice as the rheological data of the juice was observed to fit adequately into the power law model (R2>0.9). Furthermore, the enzyme-assisted juice clarification was found to reduce browning index (-14.34%) and turbidity (-19.72%) while increasing the reducing sugar content (9.55%). Unlike some conventional juice treatments, the polygalacturonase treatment preserved the antioxidant potential and the total phenolic contents of the pear juice as no significant changes were observed after the treatment. This study thus demonstrates the efficacy of a fungal polygalacturonase in improving pear juice quality as well as the potential applicability of B. bassiana enzymes in the food industry. [ABSTRACT FROM AUTHOR]

The aim of the study was to optimize the process for enzymatic extraction of pear juice from William Bartlett variety using central composite rotatable design (CCRD) and characterize its physicochemical and antioxidant properties. Pectinase enzyme concentration (0.4–2.4%), incubation temperature (20–70 °C) and incubation time (13–147 min) were evaluated as the independent factors of the optimization and the yield, clarity, TSS, acidity, turbidity, ascorbic acid, color and pectin were analyzed as responses. The results revealed that the enzyme concentration (A) significantly (p < 0.05) affected all the responses and increasing enzyme concentration led to an increase in the juice yield with better physicochemical characteristics. Enzyme concentration (1.90%), incubation temperature (30 °C) and incubation time (120 min) were determined to be the optimum condition to get the desired responses. The optimum conditions were experimentally validated. The derived optimum conditions were used for the production of pear juice which was further characterized for physicochemical and antioxidant properties. At these optimum conditions, pear juice of desirable quality in terms of physicochemical and antioxidant properties were obtained. Conclusively, pectinase enzyme assisted extraction has potential to enhance the yield and quality of pear juice during processing. [ABSTRACT FROM AUTHOR]

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The aim of this study was to evaluate the effects of lactic acid fermentation using three Lactobacillus strains (Lactiplantibacillus plantarum 90, Lactobacillus helveticus 76, and Lacticaseibacillus casei 37) in monoculture and binary mixture on phenolics profile, antioxidant activity and flavor volatiles in pear juice. Results showed that the colony counts of binary mixture were higher than monoculture in fermented pear juice. The total content of phenols was increased, while that of flavonoids was decreased significantly during fermentation (p < 0.05). Antioxidant activities in fermented peer juice including DPPH and ABTS radical scavenging abilities and ferric reducing antioxidant power (FRAP) were significantly improved (p < 0.05). Binary mixture of Lactiplantibacillus plantarum 90 and Lacticaseibacillus casei 37 fermentation exhibited strong DPPH radical scavenging ability, due to the increase in vanillic acid and arbutin contents. Furthermore, lactic acid fermentation improved the formation of alcohols, esters, acids and terpenoids, and reduced the contents of aldehydes and ketones. Thirty new compounds including 15 alcohols, seven esters, five acids, and three terpenoids were observed in fermented pear juice. Hierarchical cluster revealed that flavor volatiles in pear juice were improved dramatically by Lactobacillus strains fermentation, and there were dramatic differences between monoculture and binary mixture.

Copyright of Journal of Food Safety & Quality is the property of Journal of Food Safety & Quality Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Food Safety & Quality is the property of Journal of Food Safety & Quality Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Fruit juices are common products in modern diets due to the supply of vegetal nutrients combined with its tastiness. Nevertheless, potential contaminants, such as mycotoxins and pesticides, can be present in commercial products due to a potential carry-over. Therefore, the aim of this study was to investigate for the first time the presence of 14 Fusarium mycotoxins using a quick, easy, cheap, effective, rugged, and safe (QuEChERS)-based extraction followed by an ultra-high-performance liquid chromatography-quadrupole Orbitrap high-resolution mass spectrometry in 21 pear juice samples from Italian markets. Up to nine different mycotoxins were detected, particularly an extensive presence of zearalenone (67%, n = 21, mean value = 0.88 ng/mL). Emerging Fusarium mycotoxins enniatins B, B1, A, and A1 were also detected. Additionally, 77 pesticide residues were tentatively identified through a retrospective analysis based on a mass spectral library. The prevalent presence of some non-approved pesticides, such as ethoxyquin (64%, n = 21) and triazophos (55%, n = 21), must be highlighted. The results obtained indicate an extensive contamination of marketed pear juice with undesirable compounds, and they should be taken into consideration when performing risk assessment studies.

Abstract: Herein, we report for the first time a low‐cost and eco‐friendly carbon dot weak gel (CDWG) in the absence of any gelling agent from a pear juice as a green precursor. Our findings showed that the volatile nature of acetone, basic media, and cellulose content in pear juice played key roles in the formation of CDWG. This fabrication strategy of CDWG from a green precursor in absence of gelling agent could be more advantageous over CD‐hybrids gel. Further, the fabricated gel exhibited excitation dependent red shifted multicolor (blue‐green‐yellow‐orange) emission due to the presence of characteristic hydrophilic surface in CDs. The other unique feature of the work involved utilization of inherent fluorescent property of CDs in establishing optical interaction between 0D CDWG and 2D reduced graphene oxide (G) and graphene oxide (GO). It may be concluded that the quenching is mainly guided by the electron rich CDs and electron acceptance ability, large specific surface area of G and GO. It is also interesting to note that the introducing of gel property in CDs exhibit improved sensing efficiency and limit of detection of CDWG (1.5 μg ml−1) for G. Further, such optical sensing could be beneficial for the fabrication of optoelectronics, photovoltaic devices and sensing of bio‐molecules and metal ions. [ABSTRACT FROM AUTHOR]

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this work, a rapid and accurate surface-enhanced Raman spectroscopy (SERS) based on silver nanodots (AgNDs) array substrate method was used to detect Alternaria alternata ( A. alternata ) in both sterile water and pear juice (an example of complex food matrix). The substrate fabrication conditions were firstly optimized to obtain the maximal SERS enhancement. SERS and Raman mapping methods were then used to scan the A. alternata adsorbed on the surface of the substrate, and the intrinsic and distinct SERS signals of A. alternata were used as the basis for detection. It was found that using A. alternata in sterile water as a model sample, the method was able to detect the A. alternata with a limit of detection (LOD) as low as 1.0 × 10 3 cfu/mL. Moreover, the newly developed method could also realize rapid detection of A. alternata in pear juice, and the lowest detectable A. alternata concentration was less than 1.0 × 10 4 cfu/mL. In addition, the A. alternata concentration range from 1.0 × 10 4 cfu/mL to 1.0 × 10 6 cfu/mL could be detected by SERS mapping. This study provides a convenient method for the detection of low-level A. alternata in complex food matrix, and further information and guidance for the design of a SERS-based detection. [ABSTRACT FROM AUTHOR]

In this study, the microbial and nutritional aspects of pear juice with conventional or ultrasound (US) treatment during storage at 4 °C were studied. The conventional pasteurization was 95 °C for 5 min while US-pasteurizations (frequency 30 kHz, amplitude 70%) were 25, 45, and 65 °C for 10 min, under a probe sonicator (750 W). Control, US25 and US45 had shelf lives of 9, 12, and 15 days respectively. Ascorbic acid, total phenols, total anti oxidant capacity, and cloud value decreased in all treatments while pH, acidity, and sugars remained stable. Both treatments (P95 and US65) remained viable after 21 days of storage, however, loss of bioactive compounds in P95 (16.39%) was significantly higher than that of US65 (7.44%), indicating US-pasteurization a promising pear juice processing technology at low temperature, retaining bioactive compounds, meeting safety standards, and increasing shelf life. Practical applications Complete microbial and enzymatic deactivation is achieved at commercial thermal pasteurization techniques, but these elevated temperatures cause losses in nutritional and sensory attributes of the end product. While microbial and enzymatic deactivation in pear juice was achieved at lower temperature using thermosonication in the present study. The low temperature pasteurizations exhibited higher retention and availability of bioactive compounds than the traditional high temperature pasteurizations over the studied shelf life period. The findings of the study would pave way for the commercial processing of pear juice with improved quality and shelf life. [ABSTRACT FROM AUTHOR]

This study was carried out to investigate the effect of sonication on physicochemical parameters and microorganisms of pear juice. Ultrasound processing of fresh pear juice was done at fixed amplitude [70% (500 W) and frequency (25 kHz) for 0, 15, 30, 45 and 60 min at 25 °C. Total soluble solids, pH, titratable acidity and Ca and Mn remained stable, while the cloud value, ascorbic acid, total phenols, total flavonoids, total antioxidant capacity, sugar contents and Na, K, Fe and Mg showed a significant increase. Decreases in microbial population and P and Cu were also observed. It may be inferred that ultrasound processing for 60 min exhibited optimum results in terms of physicochemical and microbial quality. [ABSTRACT FROM AUTHOR]

Studies were conducted to develop jamun powder supplemented pear juice. Two drying methods (Hot air cabinet drying and freeze drying) were used to prepare jamun pulp powder. Jamun powder was then blended with pear juice at 1, 2, 3, 4 and 5 % levels for preparation of jamun powder supplemented pear juice. Among the drying methods used, freeze dried powder retained better bioactive compounds and possessed higher antioxidant activity as compared to hot air dried jamun powder. Analysis of color properties (L*, a*, b*) revealed lower L*, b* values and higher a* values with progression of supplementation levels indicating decreased brightness of product. Pear juice supplemented with 4 % jamun powder received highest overall acceptability scores and was chosen for development of final product. Physico-chemical characteristics of control pear juice did not vary much from when compared to jamun powder supplemented pear juice. Bioactive components mainly total phenols enhanced (9.24 % higher) with addition of jamun powder in pear juice. Addition of anthocyanins from jamun powder to pear juice upon blending improved antioxidant activity of the final product. Supplemented pear juice had 18.13 % higher antioxidant activity than pear juice without supplementation. Storage period of 6 months resulted in significant ( p < 0.05) decrease of bioactive compounds and antioxidant activity in jamun powder supplemented pear juice. [ABSTRACT FROM AUTHOR]

Microbial and enzymatic inactivation in fresh pear juice were studied under conventional and ultrasound-pasteurizations. The ultrasound-pasteurization conditions were 25, 45 and 65 °C for 10 min using a 750 W probe sonicator (frequency 20 kHz and amplitude 70%) while conventional pasteurization conditions were 65 °C for 10 min and 95 °C for 2 min. Complete inactivation of enzymes (peroxidase, pectinmethylesterase and polyphenol oxidase) and microbes (total plate count, yeast and mould) were observed in conventional pasteurization at 95 °C but this treatment also showed highest losses of ascorbic acid, total phenols, flavonoids and antioxidant capacity. Ultrasound-pasteurization at 65 °C for 10 min showed the best results in retention of ascorbic acid and other phenolic compounds with significant reduction in enzyme activities and complete inactivation of microbes. Values of pH, acidity and °Brix showed no significant changes under conventional or ultrasound-pasteurization treatments. The findings of the present study indicate that pasteurization at low temperatures in combination with ultrasound can successfully be employed for commercial processing of pear juice with improved quality. [ABSTRACT FROM AUTHOR]

In this study, a process for the production of premium quality yellowish, cloudy pear juice from low-quality fruit under low-oxygen conditions was developed. The production process consisted of (1) shredding, (2) pressing with spiral-filter technology including a vacuumised extraction cell, (3) holding in an inert gas buffer tank, (4) pasteurisation, (5) and refrigerated storage. First, the system parameters of a spiral-filter press were optimised with the aim of producing a yellowish, cloudy pear juice with the highest possible juice yield. A maximum juice yield of 78% could be obtained. Enzymatic browning during juice extraction could be suppressed as a result of the fast processing and the low air (oxygen) levels in the extraction chamber of the spiral-filter press. Furthermore, we observed that instantaneous pasteurisation at 107 °C for 6 s, subsequent aluminium laminate packaging and cold storage had only a minimum effect on the phenolic composition. [ABSTRACT FROM AUTHOR]

The combination headspace solid phase micro-extraction + gas chromatography-mass spectrometry + gas chromatography with flame ionization detector was successfully used in quantitative determination of the instrumental odor of pear juice. Esters, aldehydes, alcohols, and terpenes were the major chemical families of the pear juice odor. Twenty-six were identified and quantified, with propyl acetate, hexyl acetate, 2-methyl-1-butanol, and butyl acetate being the major compounds. α-Cyclodextrins (CD) significantly improved the color of pear juice, leading to higher values of L* and lower of scores of a*, b*, and Δ E*. However, α-CD also reduced the total concentration of volatiles in the headspace of the juice by creating inclusion complexes with volatiles; after 40 min of oxidation, total volatiles were 8.2 and 3.4 mg L in control and α-CD-treated juices, respectively. But in summary, the global quality (joint consideration of the main sensory attributes) was improved by the addition of α-CD (6.9 compared to 5.2). [ABSTRACT FROM AUTHOR]