Effect of atmospheric modification, 1-MCP and chemicals on quality of fresh-cut banana

Fresh-cut banana slices have a short shelf-life due to fast browning and softening after processing. The effects of atmospheric modification, exposure to 1-MCP, and chemical dips on the quality of fresh-cut bananas were determined. Low levels of O₂ (2 and 4 kPa) and high levels of CO₂ (5 and 10 kPa), alone or in combination, did not prevent browning and softening of fresh-cut banana slices. Softening and respiration rates were decreased in response to 1-MCP treatment (1 μL L⁻¹ for 6 h at 14 °C) of fresh-cut banana slices (after processing), but their ethylene production and browning rates were not influenced. A 2-min dip in a mixture of 1% (w/v) CaCl₂ + 1% (w/v) ascorbic acid + 0.5% (w/v) cysteine effectively prevented browning and softening of the slices for 6 days at 5 °C. Dips in less than 0.5% cysteine promoted pinking of fresh-cut banana slices, while concentrations between 0.5 and 1.0% cysteine delayed browning and softening and extended the post-cutting life to 7 days at 5 °C.     

Optimal temperature and modified atmosphere for keeping quality of fresh-cut pineapples

The influences of storage temperature and modified O₂ and CO₂ concentrations in the atmosphere on the post-cutting life and quality of fresh-cut pineapple (Ananas comosus) were studied. Temperature was the main factor affecting post-cutting life, which ranged from 4 days at 10 °C to over 14 days at 2.2 and 0 °C. The end of post-cutting life was signaled by a sharp increase in CO₂ production followed by an increase in ethylene production. The main effect of reduced (8 kPa or lower) O₂ levels was better retention of the yellow color of the pulp pieces, as reflected in higher final chroma values, whereas elevated (10 kPa) CO₂ levels led to a reduction in browning (higher L values). Modified atmosphere packaging allowed conservation of pulp pieces for over 2 weeks at 5 °C or lower without undesirable changes in quality parameters.     

Hot water and ethanol treatments can effectively inhibit the discoloration of fresh-cut sunchoke (Helianthus tuberosus L.) tubers

The main problem affecting the quality of fresh-cut sunchoke tubers is cut surface discoloration. Pre- and post-cutting hot water and ethanol treatments were evaluated for their potential to inhibit discoloration, color changes, and associated phenolic metabolism in tuber slices stored in air at 5 °C. Some of the treatments tested inhibited discoloration and changes in a* and hue color values. Slices that were post-cut treated with hot water at 50 °C for 6–8 min or 55 °C for 3–4 min and pre-cut treated with water at 50 °C for 20–25 min maintained good color for 8–12 days at 5 °C. Post-cut ethanol fumigation (150–750 μL/L for 5 h at 5 °C) can prevent discoloration for 30 d at 5 °C. Post-cut dips with ethanol solutions (3, 5, 8 or 10% for 5 min) increased shelf-life twofold or longer compared to untreated slices. Ethanol fumigation retarded the onset of wound-induced respiration rates as well as reducing maximum rates. A post-cut 10% ethanol dip also reduced respiration rates and reduced PAL activity and total phenolics. Ethanol dips had no effect and hot water treatments had no persistent effect on microbial loads over 12 d.     

Influence of pre-cutting operations on quality of fresh-cut artichokes (Cynara scolymus L.): Effect of storage time and temperature before cutting

The effect of pre-processing storage time and temperature on post-cutting quality of two artichoke cultivars (‘Catanese’ and ‘Violetto Foggiano’) was studied. Artichoke heads were harvested in January 2010 for ‘Catanese’ and in March 2011 for ‘Violetto Foggiano’ from commercial plantations. Freshly harvested artichoke heads were stored at 0, 5, and 12 °C in a humidified flow of air. Initially, and after 3 and 7 days of storage, respiration rate, weight loss, and electrolytic leakage were monitored. Moreover, at each sampling, artichokes were cut in quarters and stored for additional 3 days at 5 °C. On cut artichokes, soon after cutting and after post-cutting storage, visual appearance, color attributes (on outer bract surface, on cut bracts, and on cut receptacle surface) and phenol content were determined. Time and temperature of storage influenced quality attributes of cut artichokes, but to a different extent depending on the cultivar, whereas temperature did not affect the phenol content. ‘Violetto Foggiano’ artichokes benefited from pre-cutting low storage temperature (0 °C), whereas ‘Catanese’ showed physiological injuries on outer bract surfaces, where brown spots occurred. In both cases low temperatures during pre-cutting storage (5 and 0 °C) reduced the browning rate of the cut surface which maintained a higher L* value, compared to artichokes stored at 12 °C. Moreover, pre-cutting storage at 12 °C resulted in a reduction of quality of artichokes due to growth of floral primordia in the form of reddish tissues at the base of the receptacle for both cultivars. Management of storage conditions before cutting is therefore critical in fresh-cut processing operations of artichokes.     

Storage temperature and type of cut affect the biochemical and physiological characteristics of fresh-cut purple onions

Minimal processing of onion (Allium cepa L.) results in convenience and freshness in a single product. However, inappropriate storage of fresh-cut onion results in losses of nutritional and sensory characteristics. To further understand this phenomenon, we evaluated the effect of the storage temperature and type of cut on the quality of fresh-cut purple onions. Purple onions (cv. Crioula Roxa) were minimally processed using two types of cut (10 mm cubes and 3–5 mm thick slices) and stored at different temperatures (0, 5, 10 and 15 °C) with 85–90% relative humidity (RH) for 15 days. The following analyses were performed to evaluate the shelf life of the purple onion: pungency, total phenolic content, anthocyanin content, quercetin content, respiratory rate, color, soluble solids content, titratable acidity, pH, dryness and deterioration index (DDI), and decay index (DI). Fresh-cut onions stored at 0 °C showed less pungency, lower respiratory rate levels and less variation of total phenolic, anthocyanin and quercetin contents. In addition, the physicochemical aspects and appearance changed less with fresh-cut onions stored at 0 °C. Moreover, slicing enabled a higher stability of the physicochemical and biochemical aspects in comparison to dicing. Storage of slices at 0 °C allowed preservation for up to 15 days.     

Inhibition of browning on the surface of apple slices by short term exposure to nitric oxide (NO) gas

Freshly cut slices of apple (Malus x domestica Borkh cv. Granny Smith) were fumigated with nitric oxide (NO) gas at concentrations between 1 and 500 μl l⁻¹ in air at 20 °C for up to 6 h followed by storage at 0, 5, 10 and 20 °C in air. Exposure to nitric oxide delayed the onset of browning on the apple surface with the most effective treatment being fumigation with 10 μl l⁻¹ NO for 1 h. While nitric oxide inhibited browning in slices held at all temperatures, it was relatively more effective as the storage temperature was reduced with the extension in postharvest life over the respective untreated slices increasing from about 40% at 20 °C to about 70% at 0 °C. In a smaller study on ‘Royal Gala’, ‘Golden Delicious’, ‘Sundowner’, ‘Fuji’ and ‘Red Delicious’ slices stored at 10 °C, 10 μl l⁻¹ NO for 1 h was found to be effective in inhibiting surface browning in all cultivars.     

Effect of harvest maturity on quality of fresh-cut pear salad

Texture of an unripe pear is firm and crisp, similar to an apple. However, at the crisp stage, the flavor of pears is flat. This study evaluated the effect of harvest maturity on the quality of fresh-cut pear salad. Fruit were harvested at commercial maturity and 1-month delayed. After 2 and 5 months (1 and 4 months for delayed-harvest fruit) storage at ?1 °C, fruit were sliced into 8–12 wedges per fruit, dipped in an antibrowning solution, packaged in Ziploc bags and stored at 1 °C for up to 21 d. Delayed-harvest fruit were larger in size (≈20% increase in weight), had lower flesh firmness (≈17% decrease), lower titratable acidity content (≈20% decrease), and lower phenolic content (≈45% and 13% decreases in pulp and peel, respectively). There was no significant difference in soluble solids content. After 2 months storage, ethylene production and respiration rate were initially lower in the slices from delayed-harvest fruit, but tended to become similar after 7 d in storage at 1 °C. Delayed-harvest fruit had lower hydroxycinnamic acids and flavanols, and higher ester, alcohol, and aldehyde volatile compounds after 2–5 months storage. The results indicated that fruit salad produced with delayed-harvest pears had less browning potential and better flavor. Sensory evaluation results showed that about 80% of the panel liked slices from delayed-harvest fruit over commercial harvested, especially in terms of visual quality (65–85%), sweetness (75–95%), taste (70–80%), and overall quality (75–80%) during 21 d storage at 1 °C. The cut surface of slices appeared dry in delayed-harvest fruit when processed after 5 months in storage. However, sensory evaluation showed that panels still preferred the delayed-harvest fruit.     

Effect of hot water treatment on leaf extension growth,fresh weight loss and color of stored minimally processed leeks

Freshly harvested leeks (Allium porrum L.) were heated by immersion in water at 50, 52.5, 55 or 57.5 °C for 0–60, 0–35, 0–20 and 0–15 min, respectively. After hot water treatment, leeks were cooled in water at ambient temperature for 10 min and then cut at 22 cm from the compressed stem of the root base, weighed, had color measured and stored at 4 °C for 9 days. Untreated stalks (without immersion in a hot water bath) were used as controls. Hot water treatments at 50 °C for 40–60 min, 52.5 °C for 25–35 min, 55 °C for 17.5–20 min and 57.5 °C for 10–15 min efficiently controlled postharvest leaf extension growth in stalks stored for 9 days. However, treatments that controlled leaf extension growth showed fresh weight loss significantly higher than the control. There was only a slight effect of heat treatment on color attributes of stored minimally processed leek.     

Flesh quality and lycopene stability of fresh-cut watermelon

Red fleshed watermelons are an excellent source of the phytochemical lycopene. However, little is known about the stability of lycopene in cut watermelon. In this study, lycopene stability and other quality factors were evaluated in fresh-cut watermelon. Twenty melons each of a seeded (Summer Flavor 800) and a seedless (Sugar Shack) variety were cut into 5 cm cubes and placed in unvented polystyrene containers, sealed, and stored at 2 °C for 2, 7, or 10 days. At each storage interval, melons were evaluated for juice leakage, changes in carotenoid composition, color, soluble solids content (SSC), and titratable acidity. Headspace carbon dioxide and ethylene were monitored during storage intervals. Juice leakage after 10 days of storage averaged 13 and 11% for the seeded and seedless melons, respectively. Lycopene content decreased 6 and 11% after 7 days of storage for Summer Flavor 800 and Sugar Shack melons, respectively. β-Carotene and cis lycopene contents were 2 and 6 mg kg⁻¹ for Summer Flavor 800 and Sugar Shack, respectively, and did not change with storage. After 10 days of storage, CIE L¹ values increased while chroma values decreased, indicating a lightening in color and loss of color saturation in melon pieces. Symptoms of chilling injury, such as greatly increased juice leakage, or lesions on cubes, were not seen on the fresh-cut cut watermelon after 10 days storage at 2 °C. Puree pH increased and SSC decreased slightly after storage. Carbon dioxide levels increased and oxygen levels decreased linearly during storage, creating a modified atmosphere of 10 kPa each of CO₂ and O₂ after 10 days. Fresh-cut cut watermelon held for 7 or more days at 2 °C had a slight loss of SSC, color saturation, and lycopene, most likely caused by senescence.     

Vitamin C in broccoli (Brassica oleracea L. var. italica) flower buds as affected by postharvest light,UV-B irradiation and temperature

In this study, the changes in vitamin C, l-ascorbic acid (AA) and l-dehydroascorbic acid (DHA) levels in broccoli flower buds were examined during pre-storage and storage periods, simulating refrigerated transport with wholesale distribution and retail, respectively. Broccoli heads were pre-stored for 4 or 7 days at 0 °C or 4 °C in the dark and then stored for 3 days at 10 °C or 18 °C. During storage the broccoli heads were exposed for 12 h per day to three different levels of visible light (13, 19 or 25 μmol m⁻² s⁻¹) or a combination of visible light (19 μmol m⁻² s⁻¹) and UV-B irradiation (20 kJ m⁻² d⁻¹), or they were stored in the dark. The vitamin C content in broccoli flower buds during storage was significantly affected by pre-storage period and temperature. Higher vitamin C levels in flower buds after storage were observed for broccoli heads pre-stored for 4 days or at 0 °C as compared to those pre-stored for 7 days or at 4 °C. Storage temperature also affected vitamin C in broccoli flower buds, with higher levels observed for broccoli stored at 10 °C than at 18 °C. Hence, vitamin C in broccoli flower buds was demonstrated to decrease together with increasing pre-storage period, pre-storage temperature and storage temperature. AA in broccoli flower buds was influenced mainly by storage temperature and to a minor extent by pre-storage temperature. The DHA level and DHA/AA ratio were stable in flower buds of broccoli pre-stored for 7 days, whereas increasing tendencies for both DHA level and ratio were observed after pre-storage for 4 days. These results indicate a shift in the ascorbate metabolism in broccoli flower buds during storage at low temperatures, with its higher rate observed for broccoli pre-stored for shorter time. There were no effects of the light and UV-B irradiation treatments on vitamin C, AA and DHA levels in broccoli flower buds.     

Effect of 1-methylcyclopropene (1-MCP) on storage life of durian fruit

Fruit of cv. Monthong durian (Durio zibethinus) were treated with 0 (control) or 500 nL L⁻¹ 1-MCP for 12 h at 25 °C. Fruit were then stored at 15 °C. To determine storage life, every 3 days a batch of fruit was transferred to 25 °C. The time to ripeness (adequate eating quality) at 25 °C in controls (no 1-MCP) decreased from 5 days in freshly harvested fruit to 3 days after 18 days of storage at 15 °C. Storage life was considered adequate if the time to ripeness was ≥3 days. The storage life at 15 °C of control fruit (no 1-MCP) was therefore 18 days. After the 1-MCP treatment the time to ripeness at 25 °C was 7 days in fresh fruit, while in fruit stored at 15 °C for 30 days it was about 3 days. The storage life at 15 °C of 1-MCP-treated fruit was therefore 30 days. Pulp firmness and pulp total soluble solids (TSS) were determined after 3 day storage intervals at 15 °C and when the fruit was ripe at 25 °C. These parameters were only slightly affected by the 1-MCP treatment. Furthermore, 1-MCP had no effect on pulp color, but delayed yellowing of the fruit exterior. It is concluded that treatment with 1-MCP before storage at 15 °C extended storage life from 18 to 30 days.     

Postharvest conditioning of Satsuma mandarins for reduction of acidity and skin puffiness

Postharvest temperature and relative humidity (RH) treatments were tested for their capacity to increase the soluble solids content:titratable acidity ratio (SSC:TA ratio) and/or reduce skin puffiness of New Zealand grown ‘Miho’ Satsuma mandarin. Fruit of low SSC:TA (approximately 6.8:1) harvested in 2001 and 2002 were held at 18 or 30 °C at low (approximately 65%) or high (>95%) RH for 3 or 5 days, followed by 2 days at 10 °C (88–92% RH). In 2002, an additional treatment of high and low RH at 10 °C was examined. Treatments at 30 °C, irrespective of RH, resulted in increased SSC:TA ratios in the fruit as a result of a decrease in titratable acidity, largely a decrease in citric acid. There was little effect of temperature on SSC and the levels of individual sugars. There was no significant effect of RH on either TA or SSC. The altered metabolism was also seen in an elevated respiratory CO₂ output at 30 °C, but a decreased CO₂ output once these fruit were transferred to 10 °C, in comparison with fruit treated at lower temperatures.At 30 °C, weight loss was up to 8.5% after 5 days under low RH, but <4% under high RH. Fruit with >4% weight loss tended to have an unacceptable level of dehydration of the skin. After 5 days at 30 °C and low RH, skin puffiness, quantified from magnetic resonance images taken before and after treatment, was reduced, although fruit tended to have soft skin that could be more prone to damage.It is concluded that short high temperature treatments such as 3–5 days at 30 °C can significantly raise the SSC:TA ratio in Satsuma mandarin through a reduction in TA, and conducting these treatments under a RH >90% minimises the risk of excessive weight loss and softening of the skin.     

Postharvest nitric oxide fumigation delays fruit ripening and alleviates chilling injury during cold storage of Japanese plums (Prunus salicina Lindell)

We investigated the effects of nitric oxide (NO) fumigation on fruit ripening, chilling injury, and quality of Japanese plums cv. ‘Amber Jewel’. Commercially mature fruit were fumigated with 0, 5, 10, and 20 μL L⁻¹ NO gas at 20 °C for 2 h. Post-fumigation, fruit were either allowed to ripen at 21 ± 1 °C or were stored at 0 °C for 5, 6, and 7 weeks followed by ripening for 5 d at 21 ± 1 °C. NO-fumigation, irrespective of concentration applied, significantly (P ≤ 0.5) suppressed respiration and ethylene production rates during ripening at 21 ± 1 °C. At 21 ± 1 °C, the delay in ripening caused by NO-fumigation was evident from the restricted skin colour changes and retarded softening in fumigated fruit. NO treatments (10 and 20 μL L⁻¹) delayed the decrease in titratable acidity (TA) without a significant (P ≤ 0.5) effect on soluble solids concentration (SSC) during ripening. During 5, 6, and 7 weeks of storage at 0 °C, NO-fumigation was effective towards restricting changes in the ripening related parameters, skin colour, firmness, and TA. The individual sugar (fructose, glucose, sucrose, and sorbitol) profiles of NO-fumigated fruit were significantly different from those of non-fumigated fruit after cold storage and ripening at 21 ± 1 °C. CI symptoms, manifest in the form of flesh browning and translucency, were significantly lower in NO-fumigated fruit than in non-fumigated fruit after 5, 6, and 7 weeks storage followed by ripening for 5 d at 21 ± 1 °C. NO-fumigation was effective in reducing decay incidence in plums during ripening without storage and after cold storage at 0 °C for 5, 6, and 7 weeks. In conclusion, the postharvest exposure of ‘Amber Jewel’ plums to NO gas (10 μL L⁻¹) delayed ripening by 3–4 d at 21 ± 1 °C, and also alleviated chilling injury symptoms during cold storage at 0 °C for 6 weeks.     

Effect of cyclic exposure to ozone gas on physicochemical,sensorial and microbial quality of whole and sliced tomatoes

The effect of a humidified flow of ozone-enriched air applied cyclically (4 ± 0.5 μL L⁻¹ of O₃ for 30 min every 3 h) on metabolic behaviour and sensorial and microbial quality of whole and fresh-cut ‘Thomas’ tomatoes stored up to 15 days at 5 °C was examined. The application of O₃ initially stimulated the respiration rate in a way similar to a stress, although after 2 days, the metabolic activity decreased to a rate lower than that of control (air flow). In O₃-treated whole and sliced tomatoes a higher sugar (fructose and glucose) and organic acid (ascorbic and fumaric) content was found. The kind of cut (whole or slices) did not affect the sensitivity of tomato to O₃. In whole tomatoes, O₃ maintained the tissue firmer than in control fruit while no influence was found on slices. The O₃ treated fruit retained a good appearance and overall quality in slices but experienced a reduced aroma. Also, O₃ substantially reduced microbial counts, being more noticeable on bacteria (1.1–1.2 log₁₀ units) than on fungi (0.5 log₁₀ units). This effect was higher when the storage time was longer and when a higher O₃ level (7 μL L⁻¹) was used. O₃ did not cause any damage or off-flavour in slices or whole tomatoes. In conclusion, the assayed O₃ treatment can be useful for maintaining quality and reducing microbial populations in whole and sliced tomato.     

Temperature and relative humidity effects on quality,total ascorbic acid,phenolics and flavonoid concentrations,and antioxidant activity of strawberry

The physical qualities and antioxidant components of ‘Jewel’ strawberry fruit stored in 75, 85 or 95% relative humidity (RH) at 0.5, 10 and 20 °C for 4 days were studied. Overall fruit quality declined more rapidly at 20 °C, especially at 95% RH. Weight loss of fruit was negligible for 2 days at all temperatures but it increased at 10 °C in the lowest RH and increased rapidly from day 3 at 20 °C especially with lower RH. Firmness was maintained, or even increased, at 0.5 or 10 °C, while soluble solids concentrations (SSC) decreased at higher storage temperatures. Red color, assessed using chroma, hue and lightness, and anthocyanin concentrations were relatively unchanged at 0.5 or 10 °C but increased rapidly at 20 °C as fruit ripened. Firmness, SSC and color were not affected by RH. Total phenolic compounds were slightly higher at 20 °C than at other temperatures at all RHs. Total ascorbic acid concentrations of the fruit remained similar for the first 2 days of storage, then declined in fruit stored at 0.5 and 20 °C, but remained unchanged at 10 °C at all RHs. Total flavonoid content of fruit did not change over time at all temperatures. The total antioxidant activity of fruit was higher at 10 °C than at 0.5 and 20 °C on day 3, and no effect of RH was detected. In conclusion, while the best temperature for long-term storage is 0.5 °C, quality could be maintained at 10 °C for acceptable periods of time for marketing and may be associated with better nutritional quality.     

Respiration rate,ethylene production and biochemical variations of ackee fruit arils (Blighia sapida Köenig) stored under three temperature regimes

The storage of fruit is characterized by many physiological and biochemical changes, and this study aimed to study respiration rate, ethylene production, and other biochemical variations of ackee fruit arils (Blighia sapida), cheese variety, stored at 5, 10 and 20 °C during eight days. During storage, respiration rate decreased but ethylene production increased. Glucose, fructose, sucrose, and short chain fructooligosaccharides – 1-kestose, nystose and DP-5 – and total phenolic compounds also decreased, however, the decrease was much higher at 20 °C. The L*, a*, b, C* and H* values showed that lower temperatures preserved much better colour and visual quality, and arils stored at 5 °C were rated excellent compared to those stored at 10 and 20 °C. The quality of arils stored at 10 °C also was more than satisfactory, while arils stored at 20 °C were completely spoiled after 8 days and showed high weight losses compared to arils stored at 5 and 10 °C, which did not show any spoilage and very low weight losses. In conclusion, the results demonstrated that ackee fruit arils can be stored in very good conditions for a minimum of eight days under low temperature regimes, although at 5 °C arils showed the best shelf-life.     

Ethanol vapor prior to processing extends fresh-cut mango storage by decreasing spoilage,but does not always delay ripening

This study was undertaken to optimize ethanol vapor application as a ripening inhibitor on whole mangoes to extend fresh-cut mango shelf life. Freshly harvested mangoes were first subjected to hot water (+HW) at 46 °C for 60 or 90 min to simulate quarantine heat treatments, or remained untreated (−HW). Fruit of each batch (+ or −HW) were then held at 20–25 °C for 4 or 7 d (D4 and D7) after the hot water treatment before being exposed to ethanol vapors [0 h (E0), 10 h (E10), or 20 h (E20)]. Fruit were then peeled and cut into slices, packed in plastic clamshells, and stored at 7 °C for 15 d. Only slices from +HW-D4-E20-treated fruit maintained higher firmness, hue angle, and titratable acidity (TA) in storage. The +HW-D7-E10- or E20-treated fruit had higher hue angle than E0, but firmness, total soluble solids, TA, pH, and respiration rate did not differ. Internal ethanol and acetaldehyde were very high in slices from +HW, D4 and D7, E20 and −HW-D7-E20-treated fruit. A sensory panel could perceive higher firmness and acidity in slices from fruit treated with ethanol. However, E20 induced off-flavor, and these fruit were least preferred.Ethanol exposure on fruit was repeated with purchased mangoes that had been subjected to a commercial quarantine heat treatment. A second heat treatment of 18 h at 38 °C and 98% relative humidity was added to one batch of fruit in this experiment. Ethanol vapors did not result in delayed ripening in those mangoes. However, this treatment inhibited microbial growth. The second heat treatment did not improve fresh-cut mango shelf life, and further, microbial growth increased compared to other treatments. It is concluded that, due to inconsistent results, ethanol vapor applied for 20 h to whole mangoes prior to processing for fresh-cut is not a practical approach to delay ripening; however, at lower doses (10 h), it could be used as a safe microbial control in a fresh-cut production sanitation system.     

Improved quality retention of packaged ‘Anjou’ pear slices using a 1-methylcyclopropene (1-MCP) co-release technology

After three months storage at 0.5 °C one quarter of a lot of ‘Anjou’ pears (Pyrus communis L.) were treated with 1 μL L^?1 of 1-methylcyclopropane (1-MCP) for 8 h at 20 °C and three quarters of the fruit were left untreated at 20 °C for the same time. Treated and untreated pears were then sliced, dipped in a commercial anti-browning solution and packaged in modified atmospheric bags. Packages, containing slices from 1-MCP treated fruit, were labelled as MCP1. Slices from two thirds of the untreated fruit had one of two secondary treatments applied: (1) multi-functional co-release sachets added to the package at the time of sealing (NT), or (2) an injection of 1-MCP to sealed packages to achieve a final concentration of 1 μL L^?1 (MCP2). The last third of the slices from the untreated lot of pears were sealed into packages with no further treatment (CK). The packages were kept at 5 °C. In-package ethylene concentrations were significantly lower for the NT treated slices. NT also significantly delayed and reduced net oxygen consumption in the package headspace compared with other treatments. The NT treatment also reduced incidence of browning induced by enzymes of microbial origin, termed secondary browning (SB), and better maintained the measured juiciness of slices. In contrast, the CK, MCP1 and MCP2 treatments showed a more rapid appearance and severity of SB. Slices in packages treated with NT retained higher tissue levels of butyl, hexyl and pentyl acetate, 6-methyl-5-hepten-2-one, butanol and hexanol during storage than any of the other three treatments.     

Effect of sustained deficit irrigation on physicochemical properties,bioactive compounds and postharvest life of pomegranate fruit (cv. ‘Mollar de Elche’)

In this study, the influence of sustained deficit irrigation (SDI; 32% of reference evapotranspiration (ET₀)) on physicochemical and sensory quality and bioactive compounds of pomegranates stored for 30, 60 and 90 days in air at 5 °C + 4 days at 15 °C, at each storage period, was studied and compared to a control (100% ET₀). Fruit from SDI had higher peel redness and greater firmness, soluble solids contents, vitamin C (27%), phloretin (98%) and protocatechuic acid (10%) levels, and total antioxidant capacity (TAC) (46%) than the control. Cold storage and shelf-life did not induce significant changes in soluble solids, pH, titratable acidity, and chroma and Hue. SDI fruit had retarded development of chilling injury (CI) symptoms, which appeared after 60 days of storage in comparison to 30 days in the controls. Anthocyanins, catechin, phloretin and protocatechuic, caffeic, p-coumaric and caffeic acids contents had greater increases in SDI fruit than in controls throughout the postharvest life. TAC was significantly (P < 0.05) correlated to anthocyanins, gallic acid and total vitamin C contents. Generally, after long term storage, the fruit grown under SDI showed higher sensory and nutritional quality, more health attributes and a longer shelf-life (up to 90 days at 5 °C + 4 at 15 °C) than fruit irrigated at 100% ET₀.