scholarly journals Respiration rate and ethylene production of fresh cut lettuce as affected by cutting grade

2008 ◽  
Vol 14 (4) ◽  
pp. 354 ◽  
Author(s):  
J. MARTÍNEZ ◽  
A. CHIESTA ◽  
F. TOVAR

For designing optimal polymeric films for modified atmosphere packaging of whole heads as well as for minimally fresh processed (fresh-cut) Iceberg lettuce ‘Coolguard’, the effect of several cutting grades on respiration rate (RR) and ethylene production at 5ºC was studied. According to common industrial practices cutting grades less than 0.5 cm, between 0.5 and 1 cm, and 2 cm length were selected. Results from four experiments were compared to those obtained for whole heads in which a homogenous range of 6 to 8 ml CO2 kg-1 h-1 in RR was found. Compared to whole heads, in fresh-cut lettuce the RR was 2-fold higher. The lowest cutting grade showed the highest respiration rate, and no significant differences in RR among lettuce pieces of intermediate and the highest grades were found. No ethylene production was detected in whole heads, while in minimally processed lettuce pieces only traces were found. For avoiding risks of anaerobic respiration and excessive CO2 levels within packages containing fresh-cut lettuce pieces lower than 0.5 cm length, films with relatively high O2 permeability like standard polypropylene or low-density polyethylene must be selected.;

Foods ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 988
Author(s):  
Bernardo Pace ◽  
Imperatrice Capotorto ◽  
Michela Palumbo ◽  
Sergio Pelosi ◽  
Maria Cefola

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.


Author(s):  
Md. Azizul Haque ◽  
Md. Asaduzzaman ◽  
Md. Sultan Mahomud ◽  
Md. Rizvi Alam ◽  
Alin Khaliduzzaman ◽  
...  

AbstractFresh-cut lettuce is a very well-known salad for today's routines because it obliges minimal preparation to minimize the loss of health beneficial vitamins, minerals, antioxidants and other phytochemicals. It is a prodigious challenge to serve its consumers fresh. Quality of freshly processed lettuce under high CO2 modified atmosphere packaging (MAP) has been investigated as a realistic alternative technique for its preservation. Storage under high CO2 atmospheric treatments exhibited a significant impact in microbial development, electrolyte leakage, volatile metabolites and sensory quality of fresh-cut iceberg lettuce. This storage condition (MAP 1: 5 kPa O2 and 20 kPa CO2 balanced by N2 at 7 °C for 6 days) inhibited the growth of mesophilic bacteria and yeasts; delayed the enzymatic browning (cut-edges and intact surface) of fresh-cut iceberg lettuce and overall visual quality was also in acceptance limit. The development of off-odors was perceived in high CO2 MAP as a consequence of volatiles (ethanol and acetaldehyde) accumulation which was persisted at an inexcusable level during 6 days of storage periods.


2012 ◽  
Vol 18 (3) ◽  
pp. 197-205 ◽  
Author(s):  
WL Li ◽  
XH Li ◽  
X Fan ◽  
Y Tang ◽  
J Yun

Effects of active modified atmosphere packaging (initial O2/CO2: 5/5; 30/5; and 80/0) and passive packaging [initial O2/CO2: 20.8/0 (air)] on the antioxidant capacity and sensory quality of fresh-cut ‘Yaoshan’ pear stored at 4 °C for 12 days were investigated. Samples stored in high O2 (30% and 80%) packages had higher phenolics and anthocyanin contents compared with those in passive and low O2 packages. After 12 days of storage, phenolics and anthocyanin contents of 80% O2 samples were 2.5 and 12 times, respectively, higher than those in the passive package and 3 and 2 times higher than those in low O2 package. High O2 modified atmosphere packaging was effective in keeping free radical scavenging capacity as measured by the DPPH assay. The sensory evaluation indicated that surface color of cut fruits were stable for at least 12 days in the high O2 modified atmosphere packaging. The results suggested that high O2 modified atmosphere packaging could be used to inhibit browning and prolong the shelf life of fresh-cut ‘Yaoshan’ pears in spite of more than 50% loss in vitamin C content.


HortScience ◽  
2012 ◽  
Vol 47 (8) ◽  
pp. 1113-1116 ◽  
Author(s):  
M. Helena Gomes ◽  
Randolph M. Beaudry ◽  
Domingos P.F. Almeida

The respiratory behavior of fresh-cut melon under modified atmosphere packaging at various temperatures was characterized to assess the potential for shelf life extension through low-oxygen and to generate information for the development of appropriate packaging conditions. Cantaloupe melon (Cucumis melo var. cantalupensis ‘Olympic Gold’) cubes were packaged and stored at 0, 5, 10, and 15 °C. Packages attained gas equilibrium after 5 days at 10 °C, 6 days at 5 °C, and 10 days at 0 °C. In cubes stored at 15 °C, decay started before steady-state gas levels were reached. Respiration rates were measured and respiratory quotient calculated once steady-state O2 and CO2 partial pressures were achieved inside the packages. O2 uptake increased with temperature and O2 partial pressure (pO2 pkg), according to a Michaelis-Menten kinetics described by = [( × pO2 pkg)/( + pO2 pkg)]. Respiratory parameters were modeled as an exponential function of temperature: = {[1.34 × 10−17 × e(0.131 × T) × pO2 pkg]/[1.15 × 10−24 × e(0.193 × T) + pO2 pkg]} (R2 = 0.95), Q10 = 3.7, and Ea = 84 kJ·mol−1. A good fit to the experimental data was also obtained considering as constant: RO2 = {[4.36 × 10−14 × e(0.102 × T) × pO2 pkg]/[0.358 + pO2 pkg]} (R2 = 0.93), Q10 = 2.8, and Ea = 66 kJ·mol−1. These results provide fundamental information to predict package permeability and steady-state pO2 pkg required to prevent anaerobic conditions and maximize shelf life of fresh-cut cantaloupe. The kinetics of respiration as a function of pO2 suggests that no significant reductions in respiration rate of fresh-cut cantaloupe can be achieved by lowering O2 levels.


10.5219/1530 ◽  
2021 ◽  
Vol 15 ◽  
pp. 83-94
Author(s):  
Özlem Kizilirmak Esmer ◽  
Erinç Koçak ◽  
Aslı Şahiner ◽  
Can Türksever ◽  
Pinar Akin ◽  
...  

Fresh mushrooms have a very short shelf life, of 1 – 3 days because of their high respiration rate and lack of cuticles that protect the plant from external factors. In the case of fresh-sliced mushrooms, they will be more susceptible to spoilage reactions due to the increase in respiration rate as a result of a broader surface area. Conventional packaging materials can not meet the requirements for modified atmosphere packaging of fresh-sliced mushrooms. One of the techniques to extend the fresh-cut produce shelf life is the passive modification of modified atmosphere packaging technology. For highly respiring fresh-cut produce such as fresh-sliced mushrooms, the permeability properties of the polymeric materials might not be enough to provide an equilibrium gas concentration in the passive modification of modified atmosphere technology. In this case, the microperforated packaging materials can be used for passive modification of fresh-cut produce. But the microperforation process needs a design for the application of the appropriate number and diameter of microholes to meet the requirements of passive modified atmosphere packaging. For this reason in this research, the design of the microperforation process to be used in passive modified atmosphere packaging was based on the diameter and the number of microholes, and the shelf life of fresh-sliced mushrooms was determined. The samples were stored at 15 °C/80% RH, and pH, color, weight loss, textural, sensorial, and microbial analysis were performed periodically during storage. It was determined that the empirical equation used in this research can be applied to microperforated packaging design for fresh-sliced mushrooms. The shelf life of the fresh-sliced mushrooms packaged with microperforated packaging material was 8 days, while it was less than 7 days (4, 5, or 6 days) when packaged with non-microperforated packaging material. This result shows that the use of microperforated packaging material is effective in extending the shelf life of fresh-sliced mushrooms.


HortScience ◽  
2011 ◽  
Vol 46 (2) ◽  
pp. 273-277 ◽  
Author(s):  
Xuetong Fan ◽  
Kimberly J.B. Sokorai

This study was conducted to investigate the effect of modified atmosphere packaging (MAP) and delay of irradiation application on the quality of cut Iceberg lettuce. Overall visual quality and tissue browning of cut lettuce were evaluated using a scale of 9 to 1, whereas texture was analyzed instrumentally during 14 days of storage at 4 °C. Results showed that irradiation (0.5 and 1.0 kGy) of cut lettuce induced tissue browning when stored in air; however, when cut lettuce was stored in MAP, irradiated lettuce had better appearance than the non-irradiated ones as a result of lower O2 levels in the packages of irradiated samples compared with the levels in control packages. In general, irradiation at doses of 0.5 and 1.0 kGy did not affect firmness of the lettuce. After 14 days of MAP storage, overall visual quality of non-irradiated samples had a score of ≈4, a score below the limit of sales appeal, whereas the two irradiated samples had scores of 6.5 to 7.9, indicating the irradiated samples had a fair to good quality. Delaying irradiation by 1 day after preparation of cut lettuce did not significantly (P > 0.05) affect cut edge browning, surface browning, or overall visual quality compared with lettuce irradiated immediately after preparation. Our results suggest that MAP is essential to minimize quality deterioration caused by irradiation.


Coatings ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 569 ◽  
Author(s):  
Stefania Volpe ◽  
Silvana Cavella ◽  
Elena Torrieri

The effect of caseinate/chitosan blend on the shelf life of minimally processed apples was studied. In the first phase of the work, the effect of the biopolymer coating on the respiration rate of the minimally processed apples was studied as function of gas composition (5%, 10%, 21% of O2 with N2 as balance at 5 °C) and temperature (5 °C, 10 °C at 5% of O2 with N2 as balance). In the second phase, the shelf life of the packed product was studied during storage at 5 °C. The gas composition (O2%-CO2%) in the package headspace, relative humidity, pH, hardness, color and antioxidant capacity of the product were monitored after 0, 1, 4, 7, 11, and 14 days. The coating effectively reduced respiration rate of the product when oxygen was over 10%. In the presence of the coating, the reduction of oxygen did not affect the respiration rate. At 5% of O2, the respiration rate decreased by 50% by changing the temperature from 10 °C to 5 °C. Shelf life study showed that the chitosan—caseinate coating was able to preserve the mechanical properties and the antioxidant capacity of the product during storage by increasing the shelf life by 7 days to 11 days at 5 °C.


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