			Home About us Contact

Stem End (stem + end)

Distribution by Scientific Domains

Chemistry	50%

Selected Abstracts

Distribution of degradative enzymatic activities in the mesocarp of two melon groups

INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 5 2010
Marco Chisari
Summary The differences in polyphenol oxidase, peroxidase, pectin methylesterase and polygalacturonase activities as well as the main physical and chemical attributes of nine different slice portions (from the inner to the outer end and from the blossom to the stem end) of two groups of melon (Cucumis melo var. cantalupensis,Galia' cv. and inodorus,Piel de sapo' cv.) at commercial maturity were studied. Moving from the inner to the outer end of the pulp, physico-chemical properties, such as pH, total soluble solids and phenolics increased whereas titratable acidity, firmness and Chroma decreased in both types, reflecting different degrees of maturity within the same fruit. As for physico-chemical attributes, the enzymatic activities responsible for browning and softening phenomena showed an increasing trend moving from the inner to the outer end of mesocarp in both cv., except for polygalacturonase in cantalupensis type. [source]

EFFECTS OF ENZYME-AIDED PEELING ON THE QUALITY OF LOCAL MANDARIN (CITRUS RETICULATA B.) SEGMENTS

JOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 5 2004
FANNY LIU
ABSTRACT Pectinases are observed to selectively alter the albedo structure of citrus fruits and, hence, aid the removal of the peel and adhering albedo layer. This study was carried out to determine the optimum conditions needed to peel local mandarins using pectinases (Peelzym II, Novo Nordisk, Denmark). The experiment variables were enzyme concentration, vacuum pressure and vacuum infusion time. The mandarins were first scored from the stem end to the blossom end, followed by immersion in 1000 mL of enzyme solution at a set vacuum pressure and ambient temperature (27 ± 1C). Only one parameter was varied in any one experiment. Peelzym II at 0.4% v/w, 650 mm Hg vacuum and 16 min of vacuum time were optimal. The enzyme-peeled fruit segments were judged by the panelists using three different sensory tests to ascertain their appeal to consumers. A significant (P < 0.05) difference between enzyme-peeled and hand-peeled segments was found, with the panelists preferring the enzyme-peeled segments. [source]

Acetic Acid, Ethanol and Steam Effects on the Growth of Botrytis cinerea in vitro and Combination of Steam and Modified Atmosphere Packaging to Control Decay in Kiwifruit

JOURNAL OF PHYTOPATHOLOGY, Issue 2 2009
Anastasia L. Lagopodi
Abstract The effects of acetic acid fumigation, ethanol fumigation, and steam heat treatment on growth of Botrytis cinerea in vitro were investigated. The effect of steam heat treatments in combination with modified atmosphere packaging (MAP) on Botrytis decay development on ,Hayward' kiwifruit was also studied. The fungus was grown in Petri dishes on potato dextrose agar. Ethanol fumigation with 100 ,l/l for 3 or 6 min, or 200 ,l/l for 6 min enhanced the growth of B. cinerea. The effect of acetic acid on growth of B. cinerea was time and dosage-dependent. Fumigation with 1 ,l/l for 6 min, 2 ,l/l for 3 min, and 4 ,l/l for 3 min promoted radial growth of the fungus when compared to the growth of the untreated control. Fumigation with 2 ,l/l for 6 min delayed the growth of the fungus for the first 6 days, while fumigation with 6 ,l/l for 3 min delayed the growth of the fungus after the sixth day. Fumigation with 4 or 6 ,l/l acetic acid for 6 min, and 8 ,l/l acetic acid for 3 or 6 min resulted in complete inhibition of fungal growth. Steam heat treatment at 45°C for 6 min, and at 48, 51, and 54°C for 3 or 6 min completely inhibited fungal growth in vitro. Furthermore, steam treatments at 47, 50, and 53°C for 3 or 6 min completely inhibited decay at the stem end of kiwifruit kept at 10°C in MAP for 12 days. However, none of the steam treatments inhibited decay in wounds on the surface of the fruit kept in MAP. [source]

Combined effects of hot water treatment (HWT) and modified atmosphere packaging (MAP) on quality of tomatoes

PACKAGING TECHNOLOGY AND SCIENCE, Issue 4 2003
Suparlan
Abstract Effects of hot water treatment (HWT) and modified atmosphere packaging (MAP) on quality of tomatoes were studied. Prior to packaging with low-density polyethylene (LDPE) film (0.02,mm in thickness), tomatoes were immersed in hot water (42.5°C) for 30,min. Control tomatoes were not treated and were stored for 2 weeks at 10°C and then for 3 days at 20°C without packaging. Steady states of O2 and CO2 concentrations inside the package were about 5 and 8%, respectively, and were reached after 6 and 4 days of storage, respectively. MAP reduced weight loss of tomatoes to about 41% of that of unpackaged fruit during a 2-week storage period. The use of a combination of HWT and MAP reduced weight loss and decay, inhibited color development and maintained firmness of tomatoes but had no effect on soluble solids content or titratable acidity. HWT slightly reduced mold growth of tomatoes stored in MAP. Packaging of control fruit in MAP resulted in stimulation of mold growth around the stem end of the fruit after about 1 week of storage and also resulted in cracking and decay. HWT could be used as disinfectant for tomatoes prior to storage in MAP in order to reduce microbial growth, cracking and decay that may be caused by excessive water vapor inside the package. Copyright © 2003 John Wiley & Sons, Ltd. [source]