Packaged fresh-cut grapes are emerging as a ready-to-eat convenient food snack. Tissue injuries incurred during the grape preparation process in which the stems are manually pulled off of the grapes result in fresh-cut grapes having a shelf life
Liping Kou, Yaguang Luo, Wu Ding, Xinghua Liu, and William Conway
En-chao Liu, Li-fang Niu, Yang Yi, Li-mei Wang, You-wei Ai, Yun Zhao, Hong-xun Wang, and Ting Min
transcriptional regulatory roles in fruit and vegetable development, ripening, and senescence ( Karlova et al., 2011 ; Francesco et al., 2013 ). ERF was studied previously under low-temperature storage and vacuum packaging in fresh-cut lotus root. MAP is
Panchanadham C. Talasila, Arthur C. Cameron, and Dennis W. Joles
In one set of modified-atmosphere (MA) packages of cut broccoli (Brassica oleracea L., Italica Group), O2 partial pressures ranged from 1.2 to 3.6 kPa at 0C [88 packages, 0.00268-cm-thick low-density polyethylene (LDPE) film, 600-cm2 film area, 40±0.5 g cut broccoli], and in another set (94 packages, same film and area as before, 25±0.5 g cut broccoli) they ranged from 5.0 to 9.2 kPa. For characterizing O2 uptake as a function of O2 partial pressure and determining anaerobic fermentation induction point at 0C, a range of steady-state package O2 partial pressures was generated by placing different amounts of cut broccoli (10 to 160 g) in LDPE packages. Oxygen uptake was modeled using a Michaelis-Menten-type equation. The maximum rate of product O2 uptake when O2 partial pressure was nonlimiting and the package O2 partial pressure corresponding to half-maximum O2 uptake were estimated as 147±3 nmol·kg-1·s-1 and 0.26±0.025 kPa, respectively. Respiratory quotient and head space ethanol increased sharply below package O2 partial pressures of 0.15 kPa, indicating stimulation of fermentation within the packages. The frequency distributions of CO2 production rates were measured for 80 samples of 100 g each of cut broccoli at two O2 partial pressures (21.0 kPa and 1.3 kPa) using a flow-through method. The average coefficient of variation of the CO2 production rate was ≈5%. Frequency distributions of O2 partial pressures were modeled as a function of product-to-product variation in O2 uptake and package-to-package variation in film permeability using the estimated O2 uptake characteristics and coefficient of variation. The model was used to predict the target O2 partial pressures for the design of cut broccoli MA packages. It was predicted that the packages for cut broccoli at 0C should be designed for a target O2 partial pressure of 2.54 kPa to have actual package O2 partial pressures ≥1.0 kPa at 0.0001% probability level. Film specifications for MA packaging of cut broccoli at 0C were calculated based on the predicted target O2 partial pressures.
Randolph M. Beaudry, Arthur C. Cameron, Ahmad Shirazi, and Diana L. Dostal-Lange
Abbreviations: CA, controlled atmosphere; LDPE, low-density polyethylene; MAP, modified-atmosphere packaging; RQ, respiratory quotient. 1 Present address: Dept. of Food Science and Human Nutrition, Michigan State Univ., East Lansing, MI 48824
Victor Rodov, Batia Horev, Yakov Vinokur, Azica Copel, Yair Aharoni, and Nehemia Aharoni
Vegetable Board of Israel. We are grateful to Mr. Shimshon Omer (Ministry of Agriculture of the State of Israel, the Extension Service) and Mr. Shlomo Basher for supplying the fruit, and to StePac L.A., Ltd. for providing the packaging material. Mention of a
Sannai Gong and Kenneth A. Corey
Procedures for predicting optimum packaging conditions of modified atmosphere packages (MAP) of tomato (`Heinz 1370') were developed. The relationship between O2 consumption rate and O2 concn (RRo2) was determined using O2 depletion data collected by enclosing tomatoes in jars and sampling head space O2 concn over time. The fitted function was then used in conjunction with other input variables: (1) film permeability to O2 (PO2), (2) film surface area (A), and (3) fruit weight in packages (Wp) to develop the final predictive equation based on Fick's law of gas diffusion. Predictive power of the equation was tested by comparing the steady state O2 concn achieved experimentally with those predicted for a wide range of packaging conditions. Packaging conditions included film surface area, weight of fruit in packages, and O2 permeability of the film (0.0426 and 0.0620 ml/kg hr). Prediction curves showing steady state O2 concn vs. packaging ratio (A/Wp) closely resembled the best fit curves of data. The effect of temperature on steady state O2 concn in MA bags was also examined. Increasing temperature from 20°C to 28±2°C had little effect but decreasing temperature to 10°C led to higher in-package O2 concn. Results indicate that predictive equations can be used to select appropriate films and optimize packaging ratios to achieve desired steady state O2 concn for MAP of tomatoes.
Charles R. Hall, Benjamin L. Campbell, Bridget K. Behe, Chengyan Yue, Roberto G. Lopez, and Jennifer H. Dennis
The commercial greenhouse and nursery industries often produce crops in plastic containers of varying sizes and shapes depending on the crop and target market ( Evans and Hensley, 2004 ). Plastic containers serve the role of consumer packaging
Marisa M. Wall, Kate A. Nishijima, Lisa M. Keith, and Mike A. Nagao
control diseases, but SO 2 use is prohibited in the United States ( Jiang et al., 2002 ). Longan fruit quality may be retained through modified atmosphere packaging (MAP) in which high humidity, high CO 2 , and low O 2 levels are created inside
Elhadi M. Yahia
Grapes (Vitis vinifera L. cv. Thompson Seedless) were packed in low density (LDPE) and high density (HDPE) polyethylene bags (Bag size: 25×25 cm containing 300 g of fruit). LDPE and HDPE films had a thickness of 38.7 and 28.2 μm, water permeability of 960 and 720 g/m2.hr.atm., and O2 permeability of 7030 and 3700 cc/m2.day.atm., respectively. Carbon dioxide gas (400 cc) was introduced to the bag immediately after sealing, after 2 weeks. and/or after 4 weeks. Fruits were evaluated after 3 months at 0°C. CO2 was about 30% immediately after introducing the gas but its concentration was reduced to less than 1% within 3 to 4 days. O2 was maintained very high (higher than 10%) in all packages. Water loss and shriveling were very low. However, decay incidence was high in all packages. In-package atmospheric conditions were not appropriate in all treatments to suppress decay activities. Further studies will be carried out with films less permeable to atmospheric gases, and fruits will be evaluated after shorter storage periods.
Xuetong Fan, Kimberly J. Sokorai, Brendan A. Niemira, Robert S. Mills, and Mark Yueqian Zhen
are allowed to be treated with radiation. There have been studies on quality of irradiated fresh-cut lettuce ( Fan and Sokorai, 2002 , 2008 , 2011 ; Fan et al., 2012 ; Hagenmaier and Baker, 1997 ) showing that cut lettuce in MA packaging can