Modelling the effect of temperature on respiration rate of fresh cut papaya (Carica papaya L.) fruits

Leaf edge browning is the main factor affecting fresh-cut lettuce marketability. Dipping in organic acids as well as the low O2 modified atmosphere packaging (MAP), can be used as anti-browning technologies. In the present research paper, the proper oxalic acid (OA) concentration, able to reduce respiration rate of fresh-cut iceberg lettuce, and the suitable packaging materials aimed to maintaining a low O2 during storage, were selected. Moreover, the combined effect of dipping (in OA or in citric acid) and packaging in low O2 was investigated during the storage of fresh-cut iceberg lettuce for 14 days. Results showed a significant effect of 5 mM OA on respiration rate delay. In addition, polypropylene/polyamide (PP/PA) was select as the most suitable packaging material to be used in low O2 MAP. Combining OA dipping with low O2 MAP using PP/PA as material, resulted able to reduce leaf edge browning, respiration rate, weight loss and electrolyte leakage, preserving the visual quality of fresh-cut lettuce until 8 days at 8 °C.

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Temperature-mediated changes in microbial carbon use efficiency and <sup>13</sup>C discrimination

Biogeosciences ◽

10.5194/bg-13-3319-2016 ◽

2016 ◽

Vol 13 (11) ◽

pp. 3319-3329 ◽

Cited By ~ 8

Author(s):

Christoph A. Lehmeier ◽

Ford Ballantyne IV ◽

Kyungjin Min ◽

Sharon A. Billings

Keyword(s):

Respiration Rate ◽

Multiple Scales ◽

Microbial Transformation ◽

Co2 Flux ◽

Effect Of Temperature ◽

Organic Substrates ◽

Ecosystem Level ◽

Microbial Carbon ◽

Use Efficiency ◽

Carbon Dioxide Co2

Abstract. Understanding how carbon dioxide (CO2) flux from ecosystems feeds back to climate warming depends in part on our ability to quantify the efficiency with which microorganisms convert organic carbon (C) into either biomass or CO2. Quantifying ecosystem-level respiratory CO2 losses often also requires assumptions about stable C isotope fractionations associated with the microbial transformation of organic substrates. However, the diversity of organic substrates' δ13C and the challenges of measuring microbial C use efficiency (CUE) in their natural environment fundamentally limit our ability to project ecosystem C budgets in a warming climate. Here, we quantify the effect of temperature on C fluxes during metabolic transformations of cellobiose, a common microbial substrate, by a cosmopolitan microorganism growing at a constant rate. Biomass C specific respiration rate increased by 250 % between 13 and 26.5 °C, decreasing CUE from 77 to 56 %. Biomass C specific respiration rate was positively correlated with an increase in respiratory 13C discrimination from 4.4 to 6.7 ‰ across the same temperature range. This first demonstration of a direct link between temperature, microbial CUE, and associated isotope fluxes provides a critical step towards understanding δ13C of respired CO2 at multiple scales, and towards a framework for predicting future ecosystem C fluxes.

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Activities of several membrane and cell-wall hydrolases, ethylene biosynthetic enzymes, and cell wall polyuronide degradation during low-temperature storage of intact and fresh-cut papaya (Carica papaya) fruit

Postharvest Biology and Technology ◽

10.1016/s0925-5214(02)00177-1 ◽

2003 ◽

Vol 28 (2) ◽

pp. 219-229 ◽

Cited By ~ 65

Author(s):

Yasar Karakurt ◽

Donald J. Huber

Keyword(s):

Cell Wall ◽

Low Temperature ◽

Carica Papaya ◽

Biosynthetic Enzymes ◽

Low Temperature Storage ◽

Fresh Cut ◽

Cell Wall Hydrolases ◽

Temperature Storage

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Microbiological and Physiological Attributes of Fresh-Cut Cucumbers in Controlled Atmosphere Storage

Journal of Food Protection ◽

10.4315/jfp-19-618 ◽

2020 ◽

Vol 83 (10) ◽

pp. 1718-1725

Author(s):

YABO WEI ◽

YANYAN ZHENG ◽

YUE MA ◽

JUNMAO TONG ◽

JIAN ZHANG ◽

...

Keyword(s):

Respiration Rate ◽

Electrolyte Leakage ◽

Chlorophyll Concentration ◽

Control Group ◽

Controlled Atmosphere ◽

Cucumis Sativus L ◽

Controlled Atmosphere Storage ◽

Fresh Cut ◽

Atmosphere Storage

ABSTRACT Fresh-cut cucumbers are popular worldwide, but they are prone to spoilage due to tissue damage caused by processing. The effects of controlled atmosphere storage (CAS) at 3% O2 and 7% CO2 or 8% O2 and 2% CO2 on microorganisms and the quality of fresh-cut cucumbers (Cucumis sativus L. cv. Chinese Long) at 4°C and 90% relative humidity were investigated in this study. The results showed that compared with the control group, both controlled atmosphere treatments maintained chlorophyll concentration, appearance, and color of fresh-cut cucumbers effectively; inhibited respiration rate and polyphenoloxidase (PPO) and peroxidase (POD) activity; delayed the decrease in firmness and the increase in relative electrolyte leakage; and inhibited the growth of microorganisms on cucumbers during storage. On day 10, the chlorophyll concentration and firmness of cucumbers stored at 3% O2 and 7% CO2 was 1.15 and 1.04 times that of cucumbers stored at 8% O2 and 2% CO2, respectively. Respiration rate, relative electrolyte leakage, polyphenoloxidase activity, peroxidase activity, and levels of total bacteria, coliforms, and Pseudomonas spp. at 3% O2 and 7% CO2 were 19.79, 6.01, 5.45, 88.50, 18.07, 16.14, and 19.76% lower than at 8% O2 and 2% CO2, respectively. In conclusion, storage at 3% O2 and 7% CO2 was effective in inhibiting microorganisms and maintaining the quality of stored fresh-cut cucumbers. HIGHLIGHTS

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