Vanee Chonhenchob

Preharvest bagging with wavelength‐selective materials enhances development and quality of mango (Mangifera indica L.) cv. Nam Dok Mai #4

BACKGROUND Preharvest bagging has been shown to improve development and quality of fruits. Different light transmittance bags showed different effects on fruit quality. This study presents the benefits of using newly developed plastic bagging materials with different wavelength-selective characteristics for mangoes (cv. Nam Dok Mai #4). Mangoes were bagged at 45 days after full bloom (DAFB) and randomly harvested at 65, 75, 85, 95, and 105 DAFB. The bags were removed on the harvest days. The wavelength-selective bags (no pigment, yellow, red, blue/violet, blue) were compared with the Kraft paper bag with black paper liner, which is currently used commercially for several fruits, and with non-bagging as a control. RESULTS Bagging significantly (p⩽0.05) reduced diseases and blemishes. Mango weight at 95 DAFB was increased approximately 15% by VM and V plastic bagging, as compared to paper bagging and control. Plastic bagging accelerated mango ripening as well as growth. Plastic-bagged mangoes reached maturity stage at 95 DAFB, while non-bagged mangoes reached maturity stage at 105 DAFB. Paper bagging resulted in a pale-yellow peel beginning at 65 DAFB, while plastic bagging improved peel glossiness. CONCLUSION Preharvest bagging with different wavelength-selective materials affected mango development and quality. Bagging mangoes with VM and V materials could reduce peel defects and diseases, increase weight, size, and sphericity, improve peel appearance, and shorten the development periods of mangoes. The results suggest a favorable practice using the newly developed VM and V plastic bags in the production of mangoes, and possibly other fruits as well.

Testing and Evaluation of Quality Changes of Treated Fresh-Cut Tropical Fruits Packaged in Thermoformed Plastic Containers

Fresh-cut fruit accounted for nearly

Preliminary quantification of the permeability, solubility and diffusion coefficients of major aroma compounds present in herbs through various plastic packaging materials

300 at retail in the U.S. in 2004, with projected sales ranging between

Development of Alginate Based Edible Antifungal Film Containing Turmeric Essential Oil and Its Various Characterization

1 and

Antifungal activity of plant-derived compounds and their synergism against major postharvest pathogens of longan fruit in vitro

2 billion by 2008. The choice of packaging materials and the atmospheric conditions both inside and outside the package contribute significantly to the shelf-life of these products. This study evaluated quality changes such as firmness, color, total soluble solids (TSS), titratable acidity (TA), sensory quality, and microbial safety of fresh-cut mangoes, pineapples, melons, and mixes of these fruits. Chemical treatments to reduce browning, firmness loss, and decay for these fruits were also investigated. The most effective treatments for fresh-cut mangoes, pineapples, and melons were 0.1 M ascorbic acid, 0.2 M ascorbic acid, and 0.2 M ascorbic acid plus 0.2 M calcium chloride, respectively. These fresh-cut tropical fruits were packaged in three semi-rigid containers made of polyethylene terephthalate (PET), oriented polystyrene (OPS), and oriented poly(lactide) (OPLA). Gas composition in the package headspace and the time to reach steady-state conditions were observed to vary among fresh-cut packaging systems and affected their quality and shelf-life. The effects of package permeability, with regards to O2 and CO2, on quality and shelf-life of the fresh-cut products are discussed in this paper. Extended shelf-life was observed in fresh-cut mangoes, pineapples, and mixes packaged in PET due to reduced O2 and elevated CO2 atmosphere. Modified atmosphere of 6% O2 and 14% CO2 achieved in PET extended the shelf-life of fresh-cut pineapples from 6 to 13 days. The results suggest that shelf-life of fresh-cut fruit could be extended using appropriate semi-rigid containers.

Antimicrobial Activity of Cinnamaldehyde and Eugenol and Their Activity after Incorporation into Cellulose-based Packaging Films

BACKGROUND Aroma permeation through packaging material is an important factor when designing a package for food products. The masses of aroma compounds permeating through films over time were measured at 25 °C using a quasi-isostatic system. A model was proposed for estimating the permeability coefficients (P) of key aroma compounds present in fresh herbs (i.e. eucalyptol, estragole, linalool and citral) through major plastic films used by the food industry [i.e. low-density polyethylene (LDPE), polypropylene (PP), nylon (Nylon), polyethylene terephthalate (PET), metalised-polyethylene terephthalate (MPET) and poly(lactic acid) (PLA)]. Solubility coefficients (S) were estimated from the amount of aroma compound sorbed in the films. Diffusion coefficients (D) were estimated following from the relation P = D*S. RESULTS P and D for all four aroma compounds were highest in LDPE, except for eucalyptol, which P was slightly higher in PLA. The solubility coefficients and contact angles were highest in PLA suggesting the highest affinity of PLA to these aroma compounds. The theoretical solubility parameters were correlated with the solubility coefficients for estragole and citral, but not for eucalyptol and linalool. CONCLUSION The preliminary P, D and S of eucalyptol, estragole, linalool and citral through LDPE, PP, Nylon, PET, MPET and PLA can be useful in selecting the proper packaging material for preserving these specific aroma compounds in food products and can potentially be used for estimating the shelf life of food products based on aroma loss.

Quality changes of treated fresh-cut tropical fruits in rigid modified atmosphere packaging containers

An antifungal alginate films incorporated with turmeric oil was developed. Turmeric oil at different concentrations (0.1, 0.3 and 0.5%) was added to the matrix of 1.5% of sodium alginate, 0.243g of glycerol per gram of alginate, 0.03g of calcium carbonate and 5.4g of glucono-delta lactone per gram of calcium carbonate. Film with no turmeric oil was used as control. The physical (thickness and color), mechanical properties (tensile strength and elongation at break), barrier properties (oxygen and water vapor permeability), chemical property (Fourier transform infrared spectroscopy, FTIR) and antifungal activity of the film were evaluated. The effects of these films were studied against various important fungi i.e. Fusarium sp., Penicillium sp. and Aspergillus sp. isolated from banana. Vapor assay method was used to measure the mycelium growth. Incorporation of essential oil had an effect on various parameters of the film. With the increasing turmeric oil concentrations, thickness of the film significantly (p 0.05) increased, while total color change decreased. No significant (p > 0.05) differences were observed in tensile strength, modulus and elongation. Turmeric oil significantly (p 0.05) increased the oxygen permeability and water vapor permeability of the film as compared to the control. New peak of C-C bond on the FTIR analysis in each level of turmeric oil suggested the presence of antifungal agent. The inhibition of mycelium growth of Fusarium sp., Penicillium sp. and Aspergillus sp. were 26.36, 51.81 and 73.63%, 0.0, 9.25 and 28.70% and 0.32, 0.3 and 32.68% at 0.1, 0.3 and 0.5% of turmeric oil, respectively. In conclusion, incorporation of natural extract of the turmeric oil into alginate edible film has a great potential to inhibit the microbial growth and may be used for postharvest control of fruits.

Life cycle inventory and analysis of re-usable plastic containers and display-ready corrugated containers used for packaging fresh fruits and vegetables

The aim of this study was to find alternatives to conventional synthetic fungicides to control postharvest decay of longan fruit. The antifungal potential of thymol, carvacrol and trans-cinnamaldehyde was evaluated against four major longan pathogens, Lasiodiplodia spp., Phomopsis spp., Pestalotiopsis spp. and Geotrichum candidum, using vapor phase and direct contact methods. The vapor phase of all active compounds was more effective on fungal growth than direct contact. A volatile vapor of thymol and carvacrol had strong antifungal activity against the tested fungi, exhibiting minimum inhibitory concentration (MIC) in the range of 40 to 80 mg/L air; trans-cinnamaldehyde showed the least efficiency, with MIC ranging from 80 to 160 mg/L air for G. candidum and Phomopsis spp., while it could not inhibit Lasiodiplodia spp. and Pestalotiopsis spp. at 160 mg/L air. The minimum fungicidal concentration (MFC) of thymol and carvacrol varied from 40 to 80 mg/L air, while trans-cinnamaldehyde completely inhibited the mycelial growth of the tested fungi at higher concentrations. Mycelial growth of all tested fungi decreased with increasing active compound concentration, except for trans-cinnamaldehyde. Thymol proved to be the most effective compound against the four tested fungi, with effective concentration 50 (EC50) of 5.68 ± 0.59, 6.86 ± 0.52, 8.27 ± 0.22 and 9.99 ± 1.28 mg/L air for Lasiodiplodia spp., Phomopsis spp., Pestalotiopsis spp. and G. candidum, respectively. Fungal growth curves were adequately fitted (0.958 < R2 < 0.996) by a modified Gompertz model. For all tested fungi, the lag phase (λ) of fungal mycelia exposed to thymol and carvacrol increased, while the maximum colony diameter (A) and maximum growth rate (vm) decreased. A combination of thymol and carvacrol exhibited an antagonistic effect against G. candidum but an indifferent effect against Lasiodiplodia spp., Phomopsis spp. and Pestalotiopsis spp.