- Bet Dagan, HaMerkaz, Israel
Cucumbers are highly perishable and suffer from moisture loss, shriveling, yellowing, peel damage, and decay. Plastic packaging helps to preserve cucumber quality, but harms the environment. We examined the use of compostable modified... more
Cucumbers are highly perishable and suffer from moisture loss, shriveling, yellowing, peel damage, and decay. Plastic packaging helps to preserve cucumber quality, but harms the environment. We examined the use of compostable modified atmosphere packaging (MAP) with different perforation rates as a possible replacement for conventional plastic packaging materials. The results indicate that all of the tested types of packaging reduced cucumber weight loss and shriveling. However, compostable MAP with micro-perforations that created a modified atmosphere of between 16–18% O2 and 3–5% CO2 most effectively preserved cucumber quality, as demonstrated by reduced peel pitting, the reduced appearance of warts and the inhibition of yellowing and decay development. Overall, micro-perforated compostable packaging extended the storage life of cucumbers under both extended shelf conditions and simulated farm-to-fork supply-chain conditions and thus may serve as a replacement for the plastic pack...
Research Interests: Foods()
()
Sustainable antibacterial–antioxidant films were prepared using in situ graftings of silica nanoparticle (SNP) precursors with covalently attached bioactive agents benzoic acid (ba) or curcumin (cur) on polyvinyl alcohol (PVA). The... more
Sustainable antibacterial–antioxidant films were prepared using in situ graftings of silica nanoparticle (SNP) precursors with covalently attached bioactive agents benzoic acid (ba) or curcumin (cur) on polyvinyl alcohol (PVA). The modified PVA-SNP, PVA-SNP-ba and PVA-SNP-cur films were characterized using spectroscopic, physicochemical and microscopic methods. The prepared films showed excellent antibacterial and antioxidant activity, and increased hydrophobicity providing protection from undesired moisture. The PVA-SNP-ba films completely prevented the growth of the foodborne human pathogen Listeria innocua, whereas PVA-SNP-cur resulted in a 2.5 log reduction of this bacteria. The PVA-SNP-cur and PVA-SNP-ba films showed high antioxidant activity of 15.9 and 14.7 Mm/g TEAC, respectively. The described approach can serve as a generic platform for the formation of PVA-based packaging materials with tailor-made activity tuned by active substituents on silica precursors. Application of...
Research Interests: Polymers()
()
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Modified-atmosphere (MA) packaging using bag-in-box Xtend® liners extended the postharvest life of nonnetted Charentais-type muskmelons (Cucumis melo L., Cantalupensis Group, cv. Luna) by delaying over-ripening: excessive softening,... more
Modified-atmosphere (MA) packaging using bag-in-box Xtend® liners extended the postharvest life of nonnetted Charentais-type muskmelons (Cucumis melo L., Cantalupensis Group, cv. Luna) by delaying over-ripening: excessive softening, change of rind color, decreased soluble solids, and the development of postharvest pathogens. The most delayed fruit ripening was achieved by an atmosphere of 13-14 kPa CO2 and 7-10 kPa O2, even though ethylene concentrations were as much as 120 μL·L-1. Charentais fruit stored in this atmosphere at 6 to 7 °C maintained marketable quality for 12 days plus additional 3 days at 20 °C. In contrast, lifespan under commercial conditions in air did not exceed 3-5 days at 10 to 11 °C plus 3 days at 20 °C. The recommended MA was achieved by using the liners with low microperforation level (total perforation area 25 × 10-5 percent of the film surface), 8-9 fruit of total weight ≈5 kg per liner. MA packaging of Charentais melons makes possible their transportation ...
Research Interests:
Ultraviolet (UV) illumination (254 nm) induced production of the phytoalexin scoparone in flavedo of kumquat (Fortunella margarita Lour. Swingle cv. Nagami) and orange [Citrus sinensis (L.) Osbeck cvs. Shamouti and Valencia]. Trace... more
Ultraviolet (UV) illumination (254 nm) induced production of the phytoalexin scoparone in flavedo of kumquat (Fortunella margarita Lour. Swingle cv. Nagami) and orange [Citrus sinensis (L.) Osbeck cvs. Shamouti and Valencia]. Trace amounts of scoparone (<2.0 μg·g-1 fresh weight of flavedo) were detected in nontreated fruits. Phytoalexin accumulation in kumquat reached a peak of 530 μg·g-1 11 days after illumination, hut the amount declined rapidly, returning to a trace level 1 month after treatment.. Production of scoparone in illuminated fruits was enhanced by increasing the UV dose from 1.5 × 103 to 9.0 × 103 J·m-2 for orange and from 0.2 × 103 to 1.5 × 103 J·m-2 for kumquat and by raising the storage temperature from 2 to 17C. Phytoalexin accumulation correlated with an increase in antifungal activity of flavedo extracts. UV-illuminated kumquat fruit inoculated with Penicillium digitatum Sacc. 2 days after treatment had a lower incidence of decay than the control. Illumination...
Research Interests:
Research Interests:
Formulation determines curcumin antimicrobial effect: curcumin–cyclodextrin complexes are bactericidal, induce ROS, and target electron transport; monolithic nanoparticles are bacteriostatic, and target membranes and ATP.
Research Interests: RSC()
()
Brown mushroom (Agaricus bisporus) stalk bases from mushroom waste were treated with UV-B light to rapidly increase vitamin D2 content. Chitin was also recovered from this waste and converted into chitosan by N-deacetylation. FTIR spectra... more
Brown mushroom (Agaricus bisporus) stalk bases from mushroom waste were treated with UV-B light to rapidly increase vitamin D2 content. Chitin was also recovered from this waste and converted into chitosan by N-deacetylation. FTIR spectra showed that the mushroom chitosan were similar to chitosan from animal sources. Chitosan films were prepared using high molecular weight (HW), low molecular weight (LW) and fungal chitosan. UV-B treated mushroom particles were also incorporated into fungal chitosan films. The fungal chitosan films showed similar density, porosity and water vapor barrier properties to the LW and HW chitosan films. However, fungal chitosan films were more hydrophobic and less flexible than the LW and HW chitosan films. Addition of mushroom particles did not significantly affect mechanical or water barrier properties of the fungal chitosan films.
Research Interests:
Research Interests:
The flowers of French marigold (Tagetes patulaL.) are widely used in folk medicine, in particular for treating inflammation-related disorders. However, cellular mechanisms of this activity demand further investigation. In the present... more
The flowers of French marigold (Tagetes patulaL.) are widely used in folk medicine, in particular for treating inflammation-related disorders. However, cellular mechanisms of this activity demand further investigation. In the present work, we studied the potential ofT. patulacompounds to alleviate the oxidative stress in hydrogen peroxide-challenged human lymphoblastoid Jurkat T-cells. Crude extracts of marigold flowers and purified fractions containing flavonoids patuletin, quercetagetin, and quercetin and their derivatives, as well as the carotenoid lutein, were brought in contact with Jurkat cells challenged with 25 or 50 μM H2O2. Hydrogen peroxide caused oxidative stress in the cells, manifested as generation of superoxide and peroxyl radicals, reduced viability, arrested cell cycle, and enhanced apoptosis. The stress was alleviated by marigold ingredients that demonstrated high radical-scavenging capacity and enhanced the activity of antioxidant enzymes involved in neutralizati...
Research Interests:
... of elongation of conidia of P. digitatum, which was much higher than that of scoparone or scopoletin which are the endogenous phytoalexins of citrus fruits, or than that of citral known as the most active constitutive antifungal... more
... of elongation of conidia of P. digitatum, which was much higher than that of scoparone or scopoletin which are the endogenous phytoalexins of citrus fruits, or than that of citral known as the most active constitutive antifungal material in lemon fruit (Ben Yehoshua et al., 1992). ...
Research Interests:
Research Interests:
Research Interests:
Research Interests:
... Moshe A. Flaishman Department of Fruit Tree Sciences, Agricultural Research Organization, Volcani Center, Bet Dagan 50250, Israel ... The fig tree is indigenous to Persia, Asia Minor, and Syria and currently grows wild or feral in... more
... Moshe A. Flaishman Department of Fruit Tree Sciences, Agricultural Research Organization, Volcani Center, Bet Dagan 50250, Israel ... The fig tree is indigenous to Persia, Asia Minor, and Syria and currently grows wild or feral in most of the Mediterranean countries (Condit 1947 ...
Research Interests:
ABSTRACT Two different approaches, blending and layer-by-layer electrostatic deposition (LbL), were utilized to combine two biopolymers, gelatin and chitosan, in edible films or coatings. The performance of the blended and LbL composite... more
ABSTRACT Two different approaches, blending and layer-by-layer electrostatic deposition (LbL), were utilized to combine two biopolymers, gelatin and chitosan, in edible films or coatings. The performance of the blended and LbL composite films and single-component gelatin and chitosan films was compared in terms of mechanical, optical, and spectroscopic properties. In parallel, edible coatings based on these formulations were applied on a food model: fresh-cut melon. Physiological, textural, and microbiological parameters of the coated fruit were studied in comparison with non coated control. Surprisingly, in spite of the higher thickness, the composite films and especially the LbL formulation demonstrated enhanced water vapor permeability as compared to single-component films. The LbL film had higher strength and better elasticity than the blended one. All edible coatings containing chitosan effectively inhibited microbial growth on fresh-cut melons. The LbL formulation demonstrated the most effective inhibition of the total microbial growth especially after 5–7 days of storage, while the blended formulation demonstrated high antifungal activity after 11 days of storage. The LbL formulation demonstrated superior performance in preservation of fruit texture and also slightly reduced fruit weight loss, while the blended formulation did not improve these parameters. Both composite coatings do not obstruct fruit gas exchange and do not cause accumulation of off-flavor volatiles.
Research Interests:
Combinations of various heat treatments with individual fruit sealing, packaging in polyethylene liners or waxing were tested as means to control pathological and physiological spoilage of ‘Oroblanco’ fruit (Citrus grandis L.×C. paradisi... more
Combinations of various heat treatments with individual fruit sealing, packaging in polyethylene liners or waxing were tested as means to control pathological and physiological spoilage of ‘Oroblanco’ fruit (Citrus grandis L.×C. paradisi Macf.). The following heat treatments were used: curing at 36°C for 72 h, hot water dip at 52°C for 2 min or ‘hot drench brushing’ at 52, 56
Research Interests:
The feasibility to restrain citrus green mould (Penicillium digitatum Sacc.) during storage, by means of induced natural resistance, was investigated following combined heat and ultravioLet light C (254 nm, UV-C) treatments. Heat... more
The feasibility to restrain citrus green mould (Penicillium digitatum Sacc.) during storage, by means of induced natural resistance, was investigated following combined heat and ultravioLet light C (254 nm, UV-C) treatments. Heat treatment (HT) was performed by keeping Citrus fruits in a humid saturated room at 36 degrees C for 36 h while, the UV-C light treatment (254 nm) was carried out by illuminating the fruits with 3 or 6 kJm(-2). Physical treatments were sequential and reversely applied to un-inoculated or to 24 h-old inoculated lemons or oranges. Then, fruits were stored for 30 days at 8 or 5 degrees C with 95% relative humidity (RH) followed by a 6 day simulated marketing period at 20 degrees C and 75% RH. Constitutive (cuticle and epicuticular wax) and induced resistance (scoparone biosynthesis) were monitored and the variation in natural resistance was correlated to the decay development. HT influenced positively the constitutive factors of resistance by reducing or delayi...
Research Interests:
The ultimate goal of this study was developing antimicrobial food-contact materials based on natural phenolic compounds using nanotechnological approaches. Among the methyl-β-cyclodextrin-encapsulated phenolics tested, curcumin showed by... more
The ultimate goal of this study was developing antimicrobial food-contact materials based on natural phenolic compounds using nanotechnological approaches. Among the methyl-β-cyclodextrin-encapsulated phenolics tested, curcumin showed by far the highest activity toward Escherichia coli with a minimum inhibitory concentration of 0.4 mM. Curcumin was enclosed in liposome-type polydiacetylene/phosholipid nanovesicles supplemented with N-hydroxysuccinimide and glucose. The fluorescence spectrum of the nanovesicles suggested that curcumin was located in their bilayer region. Free-suspended nanovesicles tended to bind to the bacterial surface and demonstrated bactericidal activity toward Gram-negative (E. coli) and vegetative cells of Gram-positive (Bacillus cereus) bacteria reducing their counts from 5 log CFU mL(-1) to an undetectable level within 8 h. The nanovesicles were covalently bound to silanized glass. Incubation of E. coli and B. cereus with nanovesicle-coated glass resulted in a 2.5 log reduction in their counts. After optimization this approach can be used for controlling microbial growth, cross-contamination, and biofilm formation on food-contacting surfaces.
Research Interests:
Page 137. Transpiration and Water Stress SHIMSHON BEN-YEHOSHUA and VICTOR RODOV Agricultural Research OrganizationThe Volcani Center, Bet Dagan, Israel I. INTRODUCTION During the years that have passed ...
Research Interests:
ABSTRACT
Research Interests:
Combinations of various heat treatments with individual fruit sealing, packaging in polyethylene liners or waxing were tested as means to control pathological and physiological spoilage of ‘Oroblanco’ fruit (Citrus grandis L.×C. paradisi... more
Combinations of various heat treatments with individual fruit sealing, packaging in polyethylene liners or waxing were tested as means to control pathological and physiological spoilage of ‘Oroblanco’ fruit (Citrus grandis L.×C. paradisi Macf.). The following heat treatments were used: curing at 36°C for 72 h, hot water dip at 52°C for 2 min or ‘hot drench brushing’ at 52, 56
Research Interests:
Research Interests:
Research Interests:
Research Interests:
ABSTRACT Most of the onions (Allium cepa cv. Orlando) grown in southern Israel are treated with maleic hydrazide before storage, and are cold-stored for up to 8 months with minimal losses to rots or sprouting. Nevertheless, in most cases... more
ABSTRACT Most of the onions (Allium cepa cv. Orlando) grown in southern Israel are treated with maleic hydrazide before storage, and are cold-stored for up to 8 months with minimal losses to rots or sprouting. Nevertheless, in most cases the complete dry outer skin (tunic) cracks and loosens, and tends to fall off during storage. To improve onion postharvest quality, bulbs were harvested at 80–100% green leaf drop (top-down), leaving about 10 cm of neck above the bulb. The early harvest reduced skin cracks in 93% of the bulbs, resulting in a sturdy tunic beneath the muddy outer skin. We applied fast curing (FC) at 30 °C and 98% RH for up to 9 days postharvest: the onion neck became 52% narrower after 6 days, similar to the effect of 5 months of cold storage. FC also changed the color of the treated onion bulbs’ outer skin to a darker reddish brown. FC of onions harvested with a long neck and stored for 290 days reduced weight loss and rot by 30% and 80%, respectively, as compared to non-FC onions. The better onion quality induced by FC was accompanied by an increased number of onion skin layers (from an average of 1.8 to 4) and a higher force needed to tear the tunic (average 4.8 N as compared to 3.5 N in the control). FC compressed the effects of 5 months of cold storage into a few days, since most of the bulb neck and tunic changes measured during FC occurred only after long cold storage without FC. Although emission of the lachrymatory factor was not affected by FC, it markedly increased after 5 months of storage. Histological observation showed that FC keeps the onion tunic and inner fleshy scales intact and ensures postharvest quality, even after 8 months of cold storage. The high temperature used for FC can be reached in hot-climate storage areas with minimal energy investment.
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
The young mature-green lemon fruit manifests a significantly lower level of postharvest decay as compared to the older yellow fruit. Inoculation with Penicillium digitatum Sacc. demonstrated that the resistance of young fruit to decay is... more
The young mature-green lemon fruit manifests a significantly lower level of postharvest decay as compared to the older yellow fruit. Inoculation with Penicillium digitatum Sacc. demonstrated that the resistance of young fruit to decay is related to a factor localized in the oil glands of ...
Research Interests:
... Scoparone was induced in lemon and kumquat peel also after UV illumination (Ben-Yehoshua et al., 1991; Kim et al., 1991). Accumulation of scoparone in UV-illuminated kumquat fruit was associated with the re-duction of its decay... more
... Scoparone was induced in lemon and kumquat peel also after UV illumination (Ben-Yehoshua et al., 1991; Kim et al., 1991). Accumulation of scoparone in UV-illuminated kumquat fruit was associated with the re-duction of its decay susceptibility (Rodov et al., 1992). ...
Research Interests:
Research Interests:
The effects of wounding oil glands of lemon [Citrus limon (L.) Burm.] fruit were investigated. Young mature-green lemons demonstrated significantly lower decay incidence than older yellow fruit when their oil glands were punctured in the... more
The effects of wounding oil glands of lemon [Citrus limon (L.) Burm.] fruit were investigated. Young mature-green lemons demonstrated significantly lower decay incidence than older yellow fruit when their oil glands were punctured in the presence of postharvest wound pathogen Penicillium digitatum Sacc. Contact with the released gland content on the green lemon surface reduced the viability of P. digitatum spores approximately twice. Wounding caused rapid production of limonene hydroperoxides that persisted for only a few minutes. The magnitude depended on the physiological maturity of the fruit; mature-green fruit produced much higher levels than did yellow lemons. Furthermore, wounding of the oil glands or injection of limonene hydroperoxides into the lemon peel elicited the production of the citrus fruit phytoalexins, scoparone and scopoletin, to levels known to be effective in reducing decay caused by P. digitatum. The mature-green fruit produced about twice as much of these phytoalexins as the older yellow fruit. This induced defensive elicitation of phytoalexin production, as well as the direct effects of these antifungal compounds, markedly inhibited the pathogen in mature-green fruits but was ineffective in older yellow ones.