Changes in selected quality characteristics of minimally processed carambola (Averrhoa carambola L.) when treated with ascorbic acid

‘B 10’ carambola of ripening stage (RS) 3 and 4 were minimally processed (MP) and then dipped in 0, 15 and 30 mg L^?1 ascorbic acid (AA). The 1‐cm‐thick slices were then dried, packed into cling‐wrapped‐foam tray and stored at 7 °C for 0, 3 and 5 days. Skin colour (L*, C* and h°), flesh firmness, soluble solids concentration, vitamin C content, titratable acidity, pH, degree of browning, polyphenoloxidase (PPO) activity and sensory attributes of MP carambola treated with AA were determined. AA treatment had significant effect in decreasing cut surface browning degree but no significant effect on all the selected quality characteristics of the MP carambola. In the sensory evaluation, flesh colour, sweetness, flavour and overall taste were significantly affected by AA treatment especially at 15 mg L^?1. The RS of fruit significantly affected skin colour (C* and h°), pH and sensory attributes of colour and flavour of the MP carambola. As storage day (SD) progressed, skin colour (C* and h°), flesh firmness and vitamin C content, cut surface browning, PPO activity and all the sensory attributes of MP carambola decreased significantly. Flesh firmness of the MP carambola was affected by the interaction between AA × SD. Sensory attributes of MP carambola were affected significantly by AA × RS. All the sensory attributes of MP carambola positively correlated to each other but negatively correlated with browning degree. PPO activity positively correlated with browning degree. Copyright © 2007 Society of Chemical Industry     

The effect of the pre-treatments and the long and short-term frozen storage on the quality of raspberry (cv. Heritage)

Results are presented of the effect of pre-treatments before freezing followed by long and short-term frozen storage (12 months at –18 °C and 24 days suffering temperature fluctuations between –18 °C and –12 °C) on quality parameters of raspberry. Pre-treatments were carried out with calcium, low methoxyl pectin, a combined solution, and results compared with untreated control fruits. Kramer shear, back extrusion, compression, and multiple penetration tests were used to measure rheological behavior. One-hundred mM CaCl₂ reduced the long and short-term frozen storage induced loss of firmness. For long-term storage at –18 °C, a softening of the tissue became evident between 3 and 12 months and at each date test the stored fruits were firmer than those without storage. For short-term storage with fluctuations, the loss of firmness was evident between 0 and 24 days, and at all the testing dates the stored fruits were softer than those without storage. Results evidenced a higher cell damage in the short-term frozen storage. Coefficients of softening per day suffering fluctuation were determined, the highest values being given by Kramer shear energy and back extrusion maximum force (>1%). Short-term frozen storage affected physical and physico-chemical characteristics, increasing the saturation (r) and the anthocyanins and decreasing the ascorbic acid of the raspberries. In both storage conditions, pre-treatments reduced the drip loss, which correlated best with the Kramer shear energy. Panelists detected mainly time effect on the sensory firmness. For long-term, sensory firmness and juiciness gave the highest correlations with back extrusion maximum force, while for the short-term, sensory firmness and drip loss gave the highest correlations with the Kramer shear energy. SEM revealed different degrees of mechanical damage to structure, which accounted for rheological behavior of the fruits.     

Effect of nitrogen fertilisation levels on melon fruit quality at the harvest time and during storage

BACKGROUND: The quality of melon fruit depends upon many factors that can be affected by growing conditions and post-harvest management. The aim of this work was to investigate the effect of nitrogen fertilisation levels on the fruit quality at harvest time and during storage. Experiments were performed in an open field using melon plants (Cucumis melo L. Var. Reticulatus cv. Prodigio). The nitrogen (N) was applied through fertigation using four fertilisation levels: 0, 55, 110 and 165 kg ha⁻¹. After harvest the fruits were stored at 10 °C for 8 days. At harvest time the yield, flesh firmness, skin and pulp colours, content of carotenoids, total phenols, ascorbic acid (AsA) and ethylene production were measured on fruits differently fertilised. RESULTS: The total marketable fruit yield and fruit nitrogen content linearly increased with N levels. Antioxidant compounds decreased after storage but were not affected by N fertilisation levels. However, total carotenoids, total phenols, and AsA declined during storage. CONCLUSION: All the quality parameters did not appear to be affected by N level at either harvest time or after storage. Therefore it is advisable to reduce nitrogen input for cultivation without compromising quality and yields. Copyright © 2007 Society of Chemical Industry     

Quality Changes in Tomatoes and Resistance to Alternaria Infection as Influenced by Varying Storage Temperature

Tomato fruits were stored at 27°C continuously or at temperatures of 35°, 18°, and 27°C for 3, 2, and 4 days, respectively, before inoculation with Alternaria solani. Following inoculation, fruits were ripened at 27°C for 6 days and evaluated for quality changes and response to infection. Decreased resistance occurred in fruits stored at varying temperature, resulting in significantly larger lesions. Surface color was not significantly affected by storage and inoculation. Firmness was only significantly affected in noninoculated fruits. The pH and titratable acidity improved significantly in control fruits. Total soluble solids was only different in noninoculated fruits. Reducing sugars were lower in inoculated fruits.     

Internal quality and antioxidants content of cold-stored red sweet peppers as affected by polyethylene bag packaging and hot water treatment

Physical (weight, firmness) and compositional (sugars, organic acids, ascorbic acid, phenolic compounds and carotenoids) changes of red sweet peppers (Capsicum annuum L.) were monitored during 21 days of cold storage (at 7.5 °C); fruits were stored without packaging, packaged in low density polyethylene bags, or after hot water dipping (53 °C for 4 min) and packaging. Packaging prevented water loss, and preserved the firmness of the fresh product. Sugars (fructose and glucose) content was practically constant throughout the whole storage time, for all treatments. A moderate accumulation of citric acid was observed during storage, but no marked effects of packaging and hot water dipping on citric and malic acid content. Ascorbic acid content slightly increased in unpackaged and packaged fruits, but not in treated+packaged peppers. Hydroxycinnamics total content seemed not to be affected by cold storage, packaging or hot water treatment, whereas glycosylated flavonoids showed somewhat lowered levels during storage, particularly in the case of unpackaged and packaged+treated fruits. Regarding carotenoids content, the effect of the considered storage conditions seemed to be much smaller than that due to ripening stage. Provitamin A content showed an increasing trend in unpackaged and packaged fruits; packaged+treated peppers were characterised by a lower retention of provitamin A and a higher level of capsanthin and cucurbitaxanthin A with respect to not treated fruits. On the whole, packaging and hot water treatment did not produce noticeable adverse effects on the majority of the examined compositional quality parameters.     

EXTENDED STORAGE LIFE OF LITCHI FRUIT USING CONTROLLED ATMOSPHERE AND LOW TEMPERATURE

The postharvest quality of litchi (Litchi chinensis Sonn.) cv. Bombay stored under controlled atmosphere (CA) at 3.5% O₂and 3.5% CO₂, 2C temperature and 92–95% relative humidity was studied. Fruits were also held in regular atmosphere (RA) maintained at 2C temperature and 92–95% relative humidity. Fruits kept at normal ambient conditions were used as controls. Various quality attributes measured revealed that fruits stored in CA exhibited Hunter “a” values of 11.2 after 56 days of storage, indicating the beneficial effect of CA on retaining the red color of litchi fruits. Fruits held in RA exhibited Hunter “a” values (7.9) lower than that of CA‐stored litchi, showing that browning of litchi was noticeable in RA. Loss of weight was lowest (4.9%) for the fruits stored in CA compared to those stored in RA (11.0%) and control (33.1%). Loss of acidity and ascorbic acid content of fruits stored in CA were less than that of RA. The smallest increase of litchi firmness and pericarp puncture strength of 2.2 and 3.9 times of initial level, respectively, were observed even after 56 days of storage in CA. Total soluble solid of litchi increased from 19.3° Brix at harvest to 23.0° Brix until 48 days of storage in CA after which it declined to 22.8 °Brix. The sensory evaluation of aril color and taste showed that the fruits held in CA were rated good throughout 56 days of storage.     

Gelatine–starch films: Physicochemical properties and their application in extending the post‐harvest shelf life of avocado (Persea americana)

BACKGROUND: Several storage techniques have been developed to extend the post‐harvest shelf life of horticultural products. One method involves the use of edible or biodegradable coatings. Such coatings are made of biological materials that are used to coat fresh products, providing a semi‐permeable barrier to water vapour and gases, e.g. O₂ and CO₂. The influence of starch concentration, glycerol content and pH on the carbon dioxide permeability (CO₂P) and mechanical properties of gelatine–starch edible films were evaluated. RESULTS: Results showed that increments in the starch concentration and pH resulted in higher CO₂P values. Film puncture strength increased when the starch concentration decreased and the maximum resistance value (32.6 N) was obtained at pH 6. Deformation was mainly affected by glycerol and starch content. Some films were chosen in order to evaluate their effect, as coatings, in the post‐harvest shelf life of avocados (Persea americana Mill c.v. Hass). Fruits were immersed in the coating solutions, air dried and stored at two temperatures. Changes in colour, weight loss and pulp firmness were determined in fruits stored at 6 °C. In addition, respiration rate was measured in avocados kept at 20 °C. CONCLUSION: The application of gelatine–starch coatings delayed the ripening process of avocados, as indicated by a better pulp firmness and retention of skin colour, and lower weight loss of coated fruits in comparison with control avocados. The coatings also resulted in a delayed respiratory climacteric pattern, by 3 days, for coated fruits. Copyright © 2007 Society of Chemical Industry     

Controlled Atmosphere and Ethylene Effects on Quality of California Canning Apricots and Clingstone Peaches

Storage at 2% O₂ plus 5% CO₂ at 1.1°C maintained higher flesh firmness and lower pH and retarded decay more effectively than air storage of immature (M1) and over-mature (M3) Patterson and Tilton apricot fruits. CA storage of fruits picked at the optimum maturity stage (M2) produced little benefit over air storage, however. -Treatment with 100 ppm ethylene for 48 hours accelerated softening and color change at 20°C compared to ripening in air and may potentially be used to prepare immature apricot fruits for canning in the shortest possible time. Large differences in storageability and canned quality following storage were found among the five clingstone peach cultivars tested. Loadel and Carolyn: peaches, if in sound condition at harvest, can be stored for up to 4 wk under 2% O₂+ 5% CO₂ at 1.1°C. Andross, Klamt and Halford peaches should be stored for shorter storage periods only. Fruits ripened at 20°C with ethylene (100 ppm for 48 hr) were similar to those ripened without it in appearance, texture, and flavor.     

Development of shelf-life kinetic model for modified atmosphere packaging of fresh sliced mushrooms

Mushrooms are highly perishable and their shelf-life depends on processing, package properties and environmental conditions during storage and distribution. The aims of this work were to evaluate the effect of temperature and number of film perforations on quality and develop shelf-life kinetic model for a modified atmosphere packaging (MAP) for sliced button mushrooms. Sliced mushrooms were packed in a tray, covered with cellophane film, and stored for 7 days at four levels of temperature (0, 5, 10, and 15 °C) and three levels of perforations at each temperature ranging the number of perforations from 1 (58 perforations per m²) to 6 (349 perforations per m²). Headspace gas composition and quality parameters (weight loss, pH, firmness and colour) were measured throughout the storage period. Increasing the storage temperature required an increase of the number of perforations in order to obtain the optimum MAP conditions. Temperature had a significant effect (p < 0.05) on quality of sliced mushrooms. Firmness was identified as a critical quality parameter; therefore, a kinetic model was developed to describe the influence of temperature on firmness and predict shelf-life of sliced mushrooms. Fresh sliced mushrooms had a shelf-life of 1, 2, 4, and 7.5 days at 15, 10, 5, and 0 °C, respectively, under optimum MAP conditions.     

Chitosan-limonene coating in combination with modified atmosphere packaging preserve postharvest quality of cucumber during storage

Since cucumbers suffer from a short postharvest life, applying different technologies is increasingly used as effective ways to increase their shelf life and quality. In this study a combination of chitosan-limonene coating and MAP storage has been used as a postharvest treatment to maintain cucumber quality. Samples were stored in three different packages: A (21% O₂, macro-perforated package to be in equilibrium with air); package B (active MAP, starting concentrations 10% O₂?+?5% CO₂); package C (passive MAP starting concentrations 21% O₂?+?0.1% CO₂); they were stored at three temperatures (20, 10, and 4 °C). Quality parameters of cucumber such as weight loss, firmness, color, pH, fungal growth, T_g, organoleptic properties were determined. Interactive effects of coating, package, temperature, and storage time showed that coating and MAP in general had positive effects on several quality aspects. Coating combined with active MAP had the most positive effect on most postharvest attributes. However, using active MAP at higher temperature led to quality problems and is only useful if storage time is short. The combined usage of active MAP and chitosan-based coating on cucumber represents an innovative and interesting method for commercial application.     

Effects of Modified Atmosphere Packaging on the Physicochemical Characteristics of Ciku ( Achras sapotaL) at Various Storage Temperatures

The physicochemical changes in ciku during storage at various temperatures and the effect of various techniques of modified atmosphere packaging (MAP) at 5, 10, 15°C and ambient were examined by monitoring fruit texture, weight loss, soluble solids content, pH, sucrose, fructose, glucose, pectin, tannin, ascorbic acid and microbial infection. Under MAP, ciku could be stored for 4 weeks at 10°C and 3 weeks at 15°C, while without MAP the storage life was shorter by 1 week. Packaging in low-density polyethylene film (LDPE) was highly effective in maintaining the texture and weight of cold-stored fruits. Fruits stored at 5°C experienced chilling injury, observed as their inability to ripen properly, even after 3 days at room temperature in the presence of 50 g kg⁻¹ calcium carbide. The ascorbic acid content was highest in vacuum-packed fruits followed by the other LDPE packagings. LDPE packaged fruits also received the highest sensory scores for taste, colour, texture and overall acceptability in cold-stored ciku. The unsealed nature and heating involved in shrink wrapping did not favourably affect the storage life of ciku. MAP alleviated the chilling injury which occurred in ciku stored at 10°C but not at 5°C.     

Influence of vacuum or high-oxygen modified atmosphere packaging on quality of beef M. longissimus dorsi steaks after different ageing times

The objective of the study was to determine if beef quality parameters differ between steaks in modified atmosphere packaging (MAP; 80% O₂ and 20% CO₂) and in vacuum packaging. Both M. longissimus dorsi (LD) from ten young bulls were cut in steaks day 3 postmortem and frozen either directly or after storage for 5 or 15 days in MAP and/or vacuum. The parameters studied were Warner Bratzler shear force, colour stability, α-tocopherol content, protein oxidation, water holding capacity and sensory attributes. Steaks stored in MAP had higher shear force than steaks stored in only vacuum at all ageing times. Tenderness and juiciness were negatively affected by storage in MAP. Ageing in MAP induced higher levels of metmyoglobin compared with vacuum ageing. In conclusion, high-oxygen MAP negatively influenced shear force, thawing loss, α-tocopherol content and colour stability, as well as the sensory attributes tenderness, juiciness and to some extent meat flavour.     

RIPENING AND QUALITY CHANGES IN MANGO FRUIT AS AFFECTED BY COATING WITH AN EDIBLE FILM

Mango fruit has a relatively short storage life of about 2 to 3 weeks at 13C. In order to prolong the storage life of ‘Haden’ mangoes, fruit were coated with 3 concentrations (8,16 and 24 g.L^?1) of the edible coating film “Semperfresh” and then stored at 13C and 85% RH. Fruit were then evaluated every 4 days for up to 32 days for total soluble solids (TSS), titratable acidity (TA), pH, firmness, weight loss, color of the skin, and ascorbic acid content. All 3 concentrations applied to the fruit affected fruit ripening. TA, firmness, and green color were higher in coated fruit, and weight loss, SST, and pH were lower compared with the noncoated fruit. “Semperfresh” had no effect on decay development. Ascorbic acid decreased in all stored fruit, but this decrease was slower in coated fruit, and there were no significant differences between the different “Semperfresh” concentrations.     

Starch-based coatings: effect on refrigerated strawberry (Fragaria ananassa) quality

Edible coatings can provide an alternative for extending post-harvest life of refrigerated fruit and vegetables. The influence of different starch-based coating formulations on quality attributes of strawberries stored at 0°C and a relative humidity of 84·8% was studied. Starch sources were classified according to the amylose content in starch, with medium amylose content (potato and corn) and high amylose content (amylomaize and amylose-rich product). Quality of fruits was evaluated by weight loss, firmness retention, microbial decay, surface colour development, titratable acidity and sugar content. The effects of starch amylose content and glycerol (plasticiser) concentration on coating properties were also analysed. The coatings reduced the number of infected fruits and extended storage life of strawberries by retarding senescence. The addition of glycerol improved coating performance, with 20 g litre⁻¹ the most effective concentration. The starch source had a significant effect on surface colour development, weight loss and firmness retention. Coated strawberries produced the lowest ratios of chromaticity parameters (a/b, red/yellow) with regard to the control fruits, thus retarding senescence. High amylose content starches reduced weight loss, maintained firmness and reduced decay better than medium amylose content starches. © 1998 SCI.     

PEACH FIRMNESS DURING STORAGE AS AFFECTED BY TREE IRRIGATION SCHEDULES1

The effect on peach [Prunus persica (L) Batsch.] firmness during storage was investigated for the following tree irrigation schedules: no irrigation, irrigation beginning at budbreak until October, and irrigation beginning at stage III of fruit growth until October. Peaches (cv ‘Cresthaven’) from the three tree irrigation schedules were harvested at two ripeness stages and were stored at 2C, 90% RH. After 3, 6, 9, 13, and 16 days of storage, peach firmness was tested by a modified Effegi flesh probe test and drop impact test. From the flesh probe test, the bioyield force, maximum force, and elastic modulus were measured and from the drop impact test, the contact time, peak force/time-to-peak force, and percentage of energy absorbed were measured. None of these parameters were significantly affected by the tree irrigation schedules. Riper peaches were softer during the whole storage period. Less ripe peaches had more variation in firmness parameters during storage. The average firmness of peaches changed only slightly during the first nine days of storage, then softened quickly thereafter.     

Changes in the quality of jaboticaba fruit (Myriciaria jaboticaba (Vell) Berg. cv. Sabará) stored under different oxygen concentrations

BACKGROUND: Jaboticaba (Myriciaria jaboticaba (Vell) Berg.) is a highly perishable Brazilian berry with a shelf life of only 2 days under ambient conditions. Low temperatures and controlled atmosphere (CA) have been used to extend the shelf life of perishable fruit. Thus the aim of this study was to determine the effect of CA with varying concentrations of oxygen (1, 5, 10, 15 and 21kPa) during cold storage (12.5 °C) of ‘Sabará’ jaboticaba fruit. RESULTS: Atmospheres with lower oxygen concentrations (1 and 5 kPa O₂) significantly reduced jaboticaba respiration rate. Fruit stored under these conditions had higher L* values, and titratable acidity (TA), and lower ratios of soluble solids content (SSC)/TA. However, at the lowest concentration of oxygen (1 kPa O₂), firmness decreased markedly compared to fruits stored at higher O₂ levels (P < 0.05). After only 2 days of storage at ambient temperature jaboticaba received a score of 1.6 (dislike strongly ? 1) compared to fruit stored under CA, which scored 7.4 (like moderately ? 7). After 9 days of storage, fruit from all treatments remained above the limit of acceptability (score 5) and were rated as 6.2. With respect to appearance, statistical differences between treatments were not observed. The total anthocyanin content was not affected by oxygen concentration but decreased 40.4% during CA storage. CONCLUSION: 'Sabará' jaboticaba fruit can be satisfactorily stored under atmospheres containing 5‐21 kPa O₂ at 12.5 °C for up to 6 days. Copyright © 2011 Society of Chemical Industry     

EFFECT OF INTERMITTENT WARMING AND MODIFIED ATMOSPHERE PACKAGING ON COLOR DEVELOPMENT OF PEACHES

Peaches (Prunus persica L. Batsch cv. ‘Paraguayo’) at firm-breaker stage of maturity were stored at 0.5 C for 3 weeks. Intermittent warming (IW) for 1 day at 20C every 6 days of cold storage at 0.5C, modified atmosphere packaging (MAP) generated by 42 μm oriented polypropylene bags, and a combination of MAP and IW were applied. Changes in skin and flesh color (measured by CIELAB parameters and Chroma and Hue angle color indices) during normal postharvest ripening at 20C, during cold storage and after 3 days of post-storage ripening were studied. For commercial purposes, IW led to the same color level being reached as was found in normal postharvest ripened fruits. In contrast, the high carbon dioxide and low oxygen generated by MAP alone or combined with IW delayed color development even during post-storage ripening. Ground color measured by hue angle was the best index for monitoring color evolution during ripening and storage.     

Influence of Injection, Packaging, and Storage Conditions on the Quality of Beef and Bison Steaks

The combined effects of injection, packaging (modified atmosphere packaging [MAP] with 70% O₂/ 30% CO₂ and vacuum packaging [VP]), storage temperature (‐1 °C and +4 °C), and storage time on the color, microbial and oxidative stability of beef and bison longissimus lumborum (LL) steaks were investigated. Beef LL steaks in MAP retained their bright red color longer than bison steaks. Bison steaks developed higher 2‐Thiobarbituric acid reactive substances (TBARS) during storage, and this might have influenced the resulting rapid loss of redness from the bloomed meat. Storage at ‐1 °C in MAP provided greater color stability and a longer storage life for both meat species studied. Injection of salt/phosphate had a beneficial effect on the color stability of steaks during retail display; however, this positive effect was more pronounced for bison steaks compared with those of beef. Steaks stored overnight under MAP before retail display maintained the highest a* values for up to 5 d compared with those stored under vacuum. MAP‐OV steaks generally maintained the highest OMB content for up to 5 d during retail display compared with those stored under vacuum. Nevertheless, OMB levels were significantly (P < 0.05) lower in bison steaks compared with those of beef irrespective of packaging treatments. Injected steaks and those stored at ‐1 °C had significantly (P < 0.05) higher OMB levels compared with non‐injected counterparts and those stored at +4 °C, respectively. MAP is an excellent option for short‐term storage due to its positive effects on meat color, but for longer storage, VP may be necessary. Storing meat under vacuum and then placing it under MAP just before retail display might be another option to increase shelf life.     

Low oxygen treatment prior to cold storage decreases the incidence of bitter pit in ‘Golden Reinders’ apples

BACKGROUND: The effect of subjecting ‘Golden Reinders’ apples to a low O₂ pre‐treatment (LOT; 1–2% O₂) was evaluated as a strategy to decrease the rate of bitter pit (BP) incidence after standard cold storage (ST). Immediately after harvest, apples were stored for 10 days at 20 °C under low O₂. Thereafter, apples were cold‐stored (0–4 °C) for 4 months and changes were monitored in terms of BP incidence, fruit quality traits and mineral element concentrations. RESULTS: After 4 months cold storage, LOT apples presented a 2.6‐fold decrease in the rate of BP incidence (14%) versus the values obtained for standard cold‐stored fruits (37% BP incidence). LOT increased flesh firmness, total soluble solids and titratable acidity as compared to the quality traits determined for cold‐stored fruits. Lower cortex Ca and Mg concentrations as compared to ST apples were determined in association with LOT, 2 months after cold storage. CONCLUSION: Application of a LOT prior to cold storage may be a promising strategy to reduce the incidence of BP and preserve fruit quality, which should be further investigated. Copyright © 2009 Society of Chemical Industry     

Collagen changes in refrigerated sea bass muscle treated with pyrophosphate and stored in modified- atmosphere packaging

Changes in collagen of sea bass muscle treated with and without pyrophosphate (PP) were monitored during storage in modified-atmosphere packaging (MAP) (80% CO₂, 10% O₂ and 10% N₂) at 4 °C. No changes in acid-soluble collagen (ASC) and pepsin-soluble collagen (PSC) of sea bass muscle with and without PP treatment were observed during storage in MAP up to 21 days. However, a slight decrease in insoluble collagen (ISC) of a sample kept in MAP was found. For sea bass muscle stored under an air atmosphere ASC increased, whereas PSC and ISC decreased with a concomitant loss in the firmness