Postharvest quality and shelf life of radish microgreens as impacted by storage temperature,packaging film,and chlorine wash treatment

Microgreens are new and emerging products, which are young seedlings of vegetables and herbs. A recent study showed that microgreens contain higher nutrients compared to their mature counterparts. However, they typically have a short shelf life (1–2 days) at ambient temperature. The objective of this study was to optimize postharvest handling conditions to reduce the quality loss and extend the shelf life of daikon radish (Raphanus sativus L. var. longipinnatus) microgreens. Storage temperature, packaging film, and wash treatment were investigated. Changes in headspace composition, quality index, chlorophyll concentration, tissue electrolyte leakage, and aerobic mesophilic bacteria (AMB) and yeast & mold (Y&M) counts were monitored periodically during storage. Results indicated that (1) storage temperature significantly (P < 0.05) affected package atmosphere, product quality and shelf life. One degree Celsius was the optimal temperature for storage of radish microgreens with no chilling injury observed; (2) film oxygen transmission rate (OTR) significantly (P < 0.05) affected O₂ and CO₂ composition, but OTR did not significantly affect quality attributes during 28 days of storage at 1 °C; (3) Chlorine wash treatment (100 mg/L) significantly reduced initial microbial populations by 0.5 log cfu g⁻¹, including AMB and Y& M. However, microbial populations rebounded after day 7.     

The influence of temperature and gas mixtures on the growth of the intrinsic micro-organisms on cut endive: predictive versus actual growth

Effects of temperature and carbon dioxide concentration on the growth of mesophilic aerobic count (MAC), psychrotrophic, Gram-negative bacteria, pseudomonads and lactic acid bacteria were investigated in a case-study of minimally processed endive. When plotting population density against time, a distinct lag time was not observed. In a temperature range from 4.3–16.1°C, both combined Arrhenius–Ratkowsky-restricted growth models were used to model growth of these groups of micro-organisms. Temperature dependence of the growth rate constant for pseudomonads and psychrotrophic, Gram-negative bacteria were similar, whereas the growth rate constant of the MAC was much more temperature dependent. A combined exponential (CO₂)–Arrhenius (temperature)-restricted growth model was selected to model the number of pseudomonads and an exponential (CO₂)–Ratkowsky (temperature)-restricted growth model was selected to model the growth of MAC on cut endive. The restricted growth model was differentiated with respect to time to obtain a dynamic restricted growth model. Temperature shift-up and shift-down experiments were performed. Use of the Arrhenius equation for the temperature dependence of the growth rate constant and parameter estimates obtained under constant CO₂and temperature conditions only partially allowed us to predict the microbial evolution of minimally processed endive under dynamic conditions. Especially under temperature shift-down conditions, a systematic underestimation of growth was observed.     

Predictive modelling and selection of Time Temperature Integrators for monitoring the shelf life of modified atmosphere packed gilthead seabream fillets

The objective of the present study was to validate a kinetic model for growth of spoilage bacteria in modified atmosphere packed (MAP) gilthead seabream fillets and to select a Time Temperature Integrator (TTI). The temperature and CO₂ dependence of the growth of lactic acid bacteria in MAP gilthead seabream fillets was expressed by an Arrhenius-type model for the range of 0-15 °C and 20-80% CO₂, which was validated at isothermal, variable and chill chain conditions. A new UV activatable photochemical TTI, was kinetically studied and the influence of the level of activation on the response of the TTI was modelled. Applying the developed models, the required charging levels were estimated so that the TTI response was tailored to monitor the shelf life of fish fillets at selected MAP conditions, during the chill chain storage. A simulation experiment of the product distribution and storage in various chill chain conditions showed the applicability of the TTIs as shelf life monitors.     

Evolution of grain microbiota during hermetic storage of corn (Zea mays L.)

Respiration of biotic components of the grain ecosystem generates self-modified atmospheres (oxygen reduced and carbon dioxide enriched) during hermetic storage. The effect of temperature, moisture content and modified atmospheres on the evolution of maize microbiota is not entirely known. In this study, corn grain samples were conditioned to different moisture contents (14.3, 16.5 and 18.4%) and hermetically stored in glass jars at 15, 25 and 35 °C. Grain samples were collected at different stages of modified atmosphere evolution of each experiment: T0 (O₂: 21% initial concentration); T1 (O₂: 10%); T2 (O₂: 0%); T3 (CO₂ maximum concentration stabilized). Microbiota was quantified with Petri dish counts using selective growth media for different microbial groups. Additionally, ethanol, acetic acid and lactic acid were measured for monitoring anaerobic activity. Results indicated that there was a high correlation between water activity (a_w) and the time to reach anaerobiosis (R² of 0.85), the maximum CO₂ concentration (R² of 0.86), and the reduction of filamentous fungi and bacterial counts during hermetic storage (R² of 0.72 and 0.48, respectively). A differential behavior of the hermetic storage was observed according to a_w of the grain, and a general conceptual model is offered for its understanding. It was concluded that modified atmospheres reduced or inhibited microbial growth in stored corn, and that a_w was the most influential factor in the time to reach anaerobiosis, maximum CO₂ concentration, and the filamentous fungi and bacterial counts reduction during hermetic storage.     

Modeling of Respiration Rate of Litchi Fruit under Aerobic Conditions

Respiration of the produce and permeation of gas through the packaging films are the processes involved in creating a modified atmosphere inside a package that will extend shelf life of agricultural perishables. Thus modeling respiration rate of the selected produce is crucial to the design of a successful modified atmosphere packaging system. Two different models based on regression analysis and enzyme kinetics were developed with the help of respiration data generated at temperatures 0, 5, 10, 15, 20, 25, and 30 °C for litchi fruit using the closed system method. Temperature was found to influence the model parameters. In the model, based on enzyme kinetics, the dependence of respiration rate on O₂ and CO₂ was found to follow the uncompetitive inhibition. The enzyme kinetic model parameters, calculated from the respiration rate at different O₂ and CO₂ concentration were used to fit the Arrhenius equation against different storage temperature. The regression coefficients values were used for the prediction of respiration rate using regression model. The activation energy and respiration pre-exponential factor were used to predict the model parameters of enzyme kinetics at any storage temperature. The developed models were tested for its validity at 2 °C. The models showed good agreement with the experimentally estimated respiration rate.     

Gas exchange dynamics in modified atmosphere packaging of soft cheese

Modified Atmosphere Packaging (MAP) is a shelf-life extension technique that has been widely applied to horticultural, meat and dairy products. It relies on the interaction between product, packaging material and environment, which determines the gas composition inside the package at steady state. Therefore, MAP design needs to take into consideration O₂ consumption and CO₂ production rates of the product and the mass transfer coefficients for the gas exchange through the packaging material and how they are affected by environmental factors such as storage temperature. In this work, a mathematical model was developed for designing MAP systems for a soft cheese (camembert-type). The model was used to evaluate the effect of perforations on O₂ and CO₂ concentrations of package containing cheese, at constant and varying storage temperatures. The predicted gas composition was compared with those obtained experimentally at 293 and 285 K with packages having different numbers of perforations (1), (2) and (3). Experimental values of gas composition observed at steady state with one perforation were 0.050 and 0.148 (v/v) at 285 K for O₂ and CO₂ respectively, and 0.003 and 0.207 (v/v) at 293 K. Gas composition was found to take values between 0.009–0.058 for O₂ and 0.154–0.200 for CO₂, when the packages with a single perforation were exposed to storage temperature varying between 285 and 293 K during 14 days of storage. The model developed was able to accurately predict the gas exchange dynamics of the package throughout the storage period whether the temperature of storage was constant or not.     

Antioxidant properties and shelf‐life extension of fresh‐cut tomatoes stored at different temperatures

BACKGROUND: The feasibility of using modified atmosphere packaging (5 kPa O₂ + 5 kPa CO₂) to maintain the antioxidant properties of fresh‐cut tomatoes during shelf‐life was assessed through storage at different temperatures (5, 10, 15 and 20 °C). Health‐related compounds, antioxidant capacity, microbiological counts, physicochemical parameters and in‐package atmosphere of tomato slices were determined. RESULTS: Initial lycopene, vitamin C and phenolic contents and physicochemical parameters of tomato slices were well maintained for 14 days at 5 °C. Lycopene and total phenolic contents were enhanced over time in tomato slices stored at 15 and 20 °C. However, this increase in antioxidant compounds of fresh‐cut tomatoes during storage may be associated with excessive amounts of CO₂ (R² = 0.5679–0.7328) in the packages due to microbial growth. Although keeping tomato slices at temperatures above 10 °C increased their antioxidant content, the shelf‐life of the product was reduced by up 4 days. CONCLUSIONS: A storage temperature of 5 °C is appropriate for maintaining the microbiological shelf‐life of fresh‐cut tomatoes for up to 14 days and also allows the antioxidant properties of tomato slices to be retained over this period, thus reducing wounding stress and deteriorative changes. Copyright © 2008 Society of Chemical Industry     

Effect of muscle,ageing time and modified atmosphere packaging conditions on the colour,oxidative and microbiological stability of packed beef

The objective of this study was to evaluate the influence of two different vacuum ageing times (7 and 14 days) and the impact of the modified atmosphere packaging (MAP) configuration (gas/product ratios: 0.5 and 1 and gas composition: 70% O₂ + 30% CO₂ and 40% O₂ + 30% CO₂ + 30% N₂) on the quality of fresh beef during subsequent storage at 4 °C. For this purpose, three separate experiments were performed. For each experiment, two different muscles (Longissimus dorsi and Biceps femoris) were sampled from four double‐muscled Belgian Blue beef carcasses. Next to colour, also the evolution in microbial load, pH, O₂ and CO₂ in the headspace and lipid oxidation at the meat surface were evaluated. A vacuum ageing for 14 days compared with 7 days resulted in a higher initial microbial load on the day of MAP packaging, which resulted finally in a significantly shorter shelf life. This ageing effect was less pronounced on the colour stability and lipid oxidation of the meat samples. No significant influence of the packaging configuration on any of the analysed parameters (colour, microbial load, pH and lipid oxidation at the meat surface) was observed.     

Modeling Microbial Spoilage and Quality of Gilthead Seabream Fillets: Combined Effect of Osmotic Pretreatment,Modified Atmosphere Packaging,and Nisin on Shelf Life

ABSTRACT: The objective of the study was the kinetic modeling of the effect of storage temperature on the quality and shelf life of chilled fish, modified atmosphere-packed (MAP), and osmotically pretreated with the addition of nisin as antimicrobial agent. Fresh gilthead seabream (Sparus aurata) fillets were osmotically treated with 50% high dextrose equivalent maltodextrin (DE 47) plus 5% NaCl. Water loss, solid gain, salt content, and water activity were monitored throughout treatment and treatment conditions were selected for the shelf life study. Untreated and osmotically pretreated slices with and without nisin (2 × 10⁴ IU/100 g osmotic solution), packed in air or modified atmosphere (50% CO₂–50% air), and stored at controlled isothermal conditions (0, 5, 10, and 15 °C) were studied. Quality assessment and modeling were based on growth of several microbial indices, total volatile nitrogen, trimethylamine nitrogen, lipid oxidation (TBARS), and sensory scoring. Temperature dependence of quality loss rates was modeled by the Arrhenius equation, validated under dynamic conditions. Pretreated samples showed improved quality stability during subsequent refrigerated storage, in terms of microbial growth, chemical changes, and organoleptic degradation. Osmotic pretreatment with the addition of nisin in combination with MAP was the most effective treatment resulting in significant shelf life extension of gilthead seabream fillets (48 days compared to 10 days for the control at 0 °C).     

Effect of combined application of high pressure treatment and modified atmospheres on the shelf life of fresh Atlantic salmon

High pressure (HP) processing at low temperatures combined with modified atmosphere packaging (MA) was used for the preservation of salmon. A shelf life extension of 2 days was obtained after a HP treatment of 150 MPa for 10 min at 5°C compared to unpressurised, vacuum-packed salmon. MA storage (50% O₂+50% CO₂) alone extended the shelf life of salmon for 4 days at 5°C. When salmon had been subjected to HP treatment in the presence of 50% O₂+50% CO_2, the threshold value for microbial spoilage of salmon (7.0–7.2 log CFU/g) was not reached for at least 18 days at 5°C. Spoilage microorganisms (lactic acid bacteria, Shewanella putrefaciens) as well as pathogens (Listeria monocytogenes Scott A, Salmonella typhimurium) spiked on salmon prior to the treatment, were more susceptible to HP in the presence of 50% O₂+50% CO₂. The mode of action of compressed gases is probably related to intracellular formation of reactive oxygen species as well as to phase transition phenomena. Although microbial growth on salmon was retarded, the combined HP and MA treatments, at the settings used in this study, promoted a detrimental effect on colour and changes in the balance of oxidative rancidity.     

Optimum controlled atmospheres minimise respiration rate and quality losses while increase phenolic compounds of baby carrots

Baby carrot is a very perishable product mainly due to the abrasion of the cylindrical carrot root segments. The influence of four different controlled atmospheres (CA) (air, 2 kPa O₂ + 15 kPa CO₂, 5 kPa O₂ + 5 kPa CO₂ and 10 kPa O₂ + 10 kPa CO₂) was studied to maintain quality and prolong the shelf life of baby carrots. Respiration rate (RR), the content of vitamin C, carotenoids and phenolics by HPLC as well as the sensory quality of baby carrots during storage at 4 °C were evaluated. The lowest RR was observed in baby carrots stored under CA containing the lowest O₂ concentrations. Baby carrots under low O₂ atmospheres preserved the highest vitamin C content, as well as the individual carotenoids. The wound-induced phenolic compounds, mainly trans chlorogenic acid, increased two fold in baby carrots stored under 5 kPa O₂ + 5 kPa CO₂. In general, CA maintained the overall visual quality of baby carrots up to 8 days. Controlled atmosphere of 5 kPa O₂ + 5 kPa CO₂ can be recommended as an optimum atmosphere to maintain quality of baby carrots, increasing bioactive compounds such as chlorogenic acid and avoiding anaerobic fermentation in case of temperature abuse.     

Impact of the O2 Concentrations on Bacterial Communities and Quality of Modified Atmosphere Packaged Pacific White Shrimp (Litopenaeus Vannamei)

The importance of spoilage‐related bacteria in fresh Pacific white shrimp (Litopenaeus vannamei) under different modified atmospheres (MAs) at 4 °C and the effect of O₂ were demonstrated in the current study. The changes of bacterial communities in MA‐packed shrimp during cold storage were studied by a combined method of plate counts with isolation and identification. Three gas mixtures were applied: 80% CO₂/5% O₂/15% N₂, 80% CO₂/10% O₂/10% N₂ and 80% CO₂/20% O₂, and unsealed packages of shrimp were used as the control. In addition, the TVB‐N, pH, whiteness index, and sensory scores were also determined to evaluate the quality changes of shrimp. MA packaging effectively inhibited the increase of total psychrotrophic bacteria counts and H₂S‐producing bacteria counts by about 1.7 and 2.1 log cycles, respectively. The growth of Gram‐negative spoilage bacteria in shrimp, including Shewanella spp., Aeromonas spp., and Pseudomonas spp., was inhibited by MA packaging, but the growth rate of Gram‐positive bacteria such as lactic acid bacteria (LAB) and Brochothrix spp. were less affected by MA as effectively as Gram‐negative bacteria. In comparison with the MA‐packaged samples, the counts of H₂S producers in shrimp under a CO₂‐enriched atmosphere with 20% O₂ were slightly lower than the count in samples under an atmosphere with 5% O₂. However, MA with 20% O₂ led to higher concentrations of TVB‐N, and lower whiteness values and sensory scores. The shelf life of shrimp under 80% CO₂/10% O₂/10% N₂ has been prolonged by > 6 d in comparison with the control according to the sensory scores.     

Shelf‐Life Extension of Chill‐Stored Beef Longissimus Steaks Packaged under Modified Atmospheres with 50% O2 and 40% CO2

This study was conducted to compare the shelf‐life of beef steaks stored in different packaging conditions: overwrapped (OW) packaging and 2 modified atmosphere packaging systems (MAP): 80% O₂ MAP (80% O₂/20% CO₂) and 50% O₂ MAP (50% O₂/40% CO₂/10% N₂). Steaks were stored at 2 °C for 20 d. Headspace gas composition, microbial counts, color stability, pH, purge loss, and lipid oxidation were monitored. Among the packaging types, 50% O₂ MAP was superior to OW packaging and 80% O₂ MAP in delaying bacterial growth and extending shelf‐life to 20 d. 50% O₂ MAP also gave steaks an acceptable color during storage. No significant differences were observed in color stability of steaks packaged in both 50% O₂ MAP and 80% O₂ MAP. This study reveals 50% O₂ MAP is a realistic alternative to preserve beef steaks efficiently.     

Use of response surface methodology in shelf life extension studies of a bakery product

Effects of water activity, pH, storage temperature, concentration of potassium sorbate, CO₂ concentration in the package headspace and inoculum level on growth of Aspergillus niger, the major spoilage isolate of English style crumpets, was studied on an agar model system using an experimental design termed Response Surface Methodology. The initial screening design indicated that a_w, pH, levels of potassium sorbate, CO₂ and storage temperature were significant variables. When a central composite rotatable design was subsequently applied to four variables with pH held constant at pH 6.5 only a_w, storage temperature and CO₂ level were found to have a significant effect on mold growth. Using multiple regression analysis, a second order polynomial model was derived and used to predict the number of days to visible mold growth under various combinations of the remaining three variables. Generation of contour plots enabled selection of levels for each variable to give a product with a desired mold free shelf life. Typically, crumpets with an a_w of 0.96, packaged in 62% CO₂ had a mold free shelf life of 20 d when stored at 20°C. The observed shelf life results agreed well with predicted values on Potato Dextrose Agar and demonstrated RSM as a powerful and elegant research tool when several variables are to be evaluated simultaneously.     

Ethylene production,respiration and gas exchange modelling in modified atmosphere packaging for banana fruits

A mathematical model was developed from experimental measurements to describe the evolution of the O₂, CO₂ and ethylene in a modified atmosphere packaging system for Cavendish bananas. The respiration and ethylene production in the fruits were experimentally obtained from a closed system method and then represented by Michaelis–Menten equations of enzyme kinetics. The gas transfer through the packaging was described by a Fick's diffusion equation, and the temperature dependence was represented based on the Arrhenius law. The model was validated by packaging the fruit in perforated bags of polypropylene and low density polyethylene at 12 °C for a period of 8 days. With the developed model it was possible to satisfactorily describe the experimental evolution of the gas content in the headspace of the packages, obtaining coefficients of determination (R²) of 0.93 for the O₂ levels, 0.90–0.91 for the CO₂ levels, and 0.89–0.93 for the ethylene levels.     

Modified atmosphere packaging of filleted rainbow trout

Shelf‐lives of filleted rainbow trout (Oncorhynchus mykiss) packaged in over‐wrap, vacuum and gas mixture conditions and stored at 1 ± 1 °C were compared by measurement of pH, total volatile bases (TVB), hypoxanthine content, lipid oxidation (TBARS value), superficial counts of aerobic psychrotrophic flora and sensory analysis (colour, odour and flavour). The gas mixtures evaluated were 10% O₂ + 50% CO₂ + 40% N₂, 10% O₂ + 50% CO₂ + 40% Ar, 20% O₂ + 50% CO₂ + 30% N₂, 20% O₂ + 50% CO₂ + 30% Ar, 30% O₂ + 50% CO₂ + 20% N₂ and 30% O₂ + 50% CO₂ + 20% Ar. Sensory quality deterioration was delayed and bacterial growth as well as increases in pH, TVB and hypoxanthine levels were reduced by modified atmosphere packaging (MAP). Lipid oxidation was higher in gas packages with 20 and 30% O₂ than in those with 10% O₂. Vacuum‐packed fillets presented the lowest TBARS values. In summary, MAP gave rise to a significant extension of shelf‐life when compared with vacuum and over‐wrap packaging. No significant differences were found between the packages containing either N₂ or Ar. The best evaluated atmosphere consisted of 10% O₂ + 50%CO₂ + 40% N₂/Ar. © 2002 Society of Chemical Industry     

Evaluation of different varieties of cauliflower for minimal processing

The impact of minimal processing technology on the sensory quality and the growth of micro‐organisms in eight varieties of cauliflower packaged in four different films (one PVC and three P‐Plus) was measured and quantified during more than 25 days of storage at 4 °C. Other important parameters such as weight loss and gas concentration in the packages were also determined. The composition of the atmosphere in the packages of minimally processed cauliflower depended on both the permeability of the film used for the packaging and the variety of cauliflower. When establishing shelf‐life, loss of sensory quality was the deciding factor rather than loss of microbiological quality. The initial microbial load proved more important than the composition of the atmosphere inside the packages. In sensory evaluation the most important aspect was colour. In instrumental evaluation, coordinate b* was the main means of estimating shelf‐life. The combination of P‐Plus 120 film and varieties of cauliflower of large size and great vigour allowed the atmosphere inside the packages to have an O₂ level below 10% and a CO₂ level above 10%. That atmosphere composition proved essential for maintaining the sensory quality of minimally processed cauliflower. In these conditions, samples attained a shelf‐life of more than 25 days. However, the different behaviours of the cauliflower varieties make it necessary to establish particular packaging conditions. The use of less permeable films than those used in this study, or the use of actively modified atmospheres, could be an alternative for those varieties that require special packaging conditions when processed using this technology. Copyright © 2006 Society of Chemical Industry     

Effect of packaging chickpeas with CO2 modified atmospheres on mortality of Callosobruchus chinensis (Coleoptera: Chrysomelidae)

High CO₂ modified atmosphere packaging (MAP) is a sustainable alternative for pest control in stored products. The effectiveness of this method varies depending on the CO₂ concentration used, insect exposure time, temperature, humidity, the tested insect species, and the insect's stage of development. One factor that substantially influences the concentration of CO₂ available inside the packages, and therefore the effectiveness of the treatment, is the sorption of gas in the commodity. This study evaluated the impacts of packaging chickpeas in modified atmospheres of 50% and 90% CO₂ with filling ratios (proportion of grain relative to the volume of the package) of 1% and 96% grain on the mortality of C. chinensis eggs and pupae and on the fecundity of the females emerging from the surviving individuals. In packages with a 96% filling ratio, CO₂ concentration in the headspace of packages reduced to 60% and 30% from initial concentrations of 90% and 50% (respectively) in the first 24 h of exposure. Despite this reduction in CO₂ concentrations, no differences in the mortality of C. chinensis eggs and pupae were observed between these packages and those with a 1% filling ratio. The estimated exposure time to achieve 95% mortality (LT₉₅) of the eggs ranged from 38 to 68 h; for pupae, it ranged from 142 to 248 h. The fecundity of females that emerged from the surviving pupae decreased after 48 h of exposure to CO₂, but the fecundity of females that emerged from surviving eggs was not affected by exposure time, MAPs, or filling ratio. Therefore, effective pest control can be accomplished with the use of sufficient treatment times to eradicate the most tolerant developmental stages, regardless of whether the packages are full or not.     

The sensory and microbiological quality of fresh sliced mushroom (Agaricus bisporus L.) packaged in modified atmospheres

The effect of modified atmospheres, generated by using different packaging films, on the quality of sliced mushrooms was evaluated. The carbon dioxide and oxygen content inside the packages as well as the colour, texture, weight loss, sensory attributes, mesophiles, psychrotrophs, Pseudomonas fluorescens, faecal coliforms, Escherichia coli and anaerobic spores were determined. Modified atmospheres containing 2.5% CO₂ and 10–20% O₂ reduced the microbial counts and improved the mushrooms’ appearance when compared with an air atmosphere. Modified atmospheres containing 15% CO₂ and <0.1% O₂ inhibited mushroom development and toughening and reduced microbial growth. Although these atmospheres had no effect on colour, they did allow the development of off odours and anaerobic spores were detected. No differences in microbial growth or mushroom spoilage were observed under the different moisture contents generated in the packages at 4 °C. Aerobic bacteria counts were considered very high even at the beginning.     

QUALITY CHANGES IN FRESH‐CUT SPINACH (SPINACIA OLERACEA) UNDER MODIFIED ATMOSPHERES WITH PERFORATIONS

ABSTRACT

Fresh‐cut spinach leaves were stored for 4 days at 15C and 75% relative humidity under modified atmosphere packaging to assess the impact of differential in‐pack gas atmospheres generated through different packaging films and variable in‐pack weight on the quality of stored produce. After 4 days of storage, retention of chlorophyll, β‐carotene and ascorbic acid was better in low‐density polyethylene (LDPE) packages than in polypropylene (PP) packages. LDPE film‐packaged samples had higher phenolic content than PP film‐packaged samples. Low in‐pack O₂ (1–2 kPa) along with the buildup of CO₂ (8–10 kPa) seems to have enhanced the retention of antioxidant components, i.e., β‐carotene and ascorbic acid, in LDPE packages. This helped in chlorophyll retention and also prevented formation of oxidation compounds of phenols that otherwise caused browning of cut surfaces. Thus, O₂ and CO₂ permeability of packaging film or in‐pack weight of produce might be such that equilibrated O₂ partial pressures remain near to 1–2 kPa so as to affect a beneficial increase in the phenolic content along with concomitant retention of chlorophyll.

PRACTICAL APPLICATIONS

Fresh‐cut spinach leaves have received an enormous demand due to their utility in various traditional Indian preparations. Shelf life and quality of fresh‐cut produce may be greatly reduced due to high rates of respiration. Traditional packaging and handling techniques reduce the shelf life and sensory quality of fresh‐cut spinach. Temperature control and atmospheric modifications help to maintain produce quality by reducing respiration rate and enhance shelf life by minimizing the adverse effects of cutting. This research focused on evaluation of respiratory behavior of fresh‐cut spinach leaves at a temperature commonly encountered during transportation and retail distribution, i.e., 15C, and the effect of different polymeric films and in‐pack weights on produce quality. The results of the study suggest that packaging of fresh‐cut spinach in polymeric film packages could maintain the sensory quality and reduce degradation of various physicochemical constituents. Utilization of the results for proper design of modified atmosphere packages for this highly perishable produce can prove to be extremely beneficial for safe storage and transportation to urban retail markets.