FRUIT QUALITY OF COLD STORED SWEET CHERRIES INFESTED WITH CODLING MOTH

The effect of codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae), infestation on the quality of sweet cherry, Prunus avium (L.) L., fruit was studied. Each cherry was infested with one first instar codling moth and held at 3.3C for 0 (control), 1, 2, 4, 7, 10, or 14 days. After cold storage, fruits were maintained at 25C and observed periodically for damage using a visual scale from 0 as no damage, to 9 as complete destruction. Two groups of ‘Bing’ cherries were examined, one from an organically grown orchard and the other from a commercial orchard with conventional chemical control. Uninfested fruits maintained quality for one month at 25C whereas infested fruits had a damage rating of 2 by the fifth day. Infested organic fruits deteriorated faster than the conventional cherries. Larvae were often not detected because of fruit deterioration and fungal contamination. Fruit quality deterioration due to codling moth infestation is an important component of the Systems Approach for quarantine security for cherries exported to Japan. Infested fruit would rapidly deteriorate as the result of decay and be culled at time of packing.     

RADIO FREQUENCY‐HOT WATER DIPS FOR POSTHARVEST CODLING MOTH CONTROL IN APPLES*

A combination radio frequency‐hot water dip method was examined as a potential quarantine treatment against fifth instars of the codling moth, Cydia pomonella L. (Lepidoptera: Tortricidae), in apples, Malus sylvestris (L.) var. domestica (Borkh.) Mansf., which were intended for export to Japan. The apples were initially exposed to 27.12‐MHz radio frequency energy at 12 kW for 2.75 min and were then submerged in a range of hot water dips (48–50C) for different durations. Efficacious tests were at 48C for >2 h, at 49C for >50 min and at 50C for >40 min. Fruit quality tests indicated that the best hot water parameters were at 50C for 40 min. Fruit quality after 2 weeks was cultivar dependent where “Fuji” apples tolerated heat treatment better than “Delicious” and “Gala” apples. None of the treated fruits were acceptable after 60 days. Regardless of cultivar, heat treatment resulted in loss of both peel and fresh colors, coupled with reduced firmness and increased external and internal damage.     

RADIO FREQUENCY PULSE APPLICATION FOR HEATING UNIFORMITY IN POSTHARVEST CODLING MOTH (LEPIDOPTERA: TORTRICIDAE) CONTROL OF FRESH APPLES (MALUS DOMESTICA BORKH.)

A radio frequency (RF) treatment, with a pulse mode to increase heating uniformity, was examined as a potential quarantine treatment against fifth instars of the codling moth, Cydia pomonella L. (Lepidoptera: Tortricidae), in apples, Malus sylvestris L. var. domestica (Borkh.) Mansf., intended for export to Japan. Apples were exposed in water baths to 27.12‐MHz RF energy at 12 kW with a pulse mode of 30 s‐on/30 s‐off for different durations. The temperature uniformity was determined by measurements at 12 sites evenly spaced at two depths in the fruit. The most promising exposure time was 29 min. The efficacy of the treatment with the pulse mode was examined against the codling moth larvae by using exposures between 27 and 30 min and up to 30 min of holding time in bath after treatment. The treatment that killed all larvae with the least amount of energy was the 29‐min exposure with 50‐min holding time. This treatment was appraised for fruit quality in “Delicious” apples. Some injury was observed when treated fruits were removed from 1C storage after 30 days. When these fruits were held at 25C for 1 week, all were too damaged to evaluate for fruit quality. Although pulse mode increased heating uniformity in the fruit, the thermal requirements to control codling moth larvae may exceed the injury threshold of the fruits.     

QUALITY CHARACTERISTICS OF 'BING' AND 'RAINIER' SWEET CHERRIES TREATED WITH GIBBERELLIC ACID, FOLLOWING FUMIGATION WITH METHYL BROMIDE

Methyl bromide (MeBr) fumigation did not significantly influence weight loss, fruit color or soluble solids of either ‘Bing’ or ‘Rainier’ sweet cherries. MeBr increased pitting and reduced objective and subjective stem color of both cultivars. There was a slight advantage in quality (bruising, pitting and stem color) for the 48g/m³ at 12°C over the 64g/m³ at 6°C MeBr treatment. As fumigation temperature increased, bruising and pitting increased and stem color decreased. Use of gibberellic acid resulted in increased firmness for ‘Bing’ cherries and superior fruit and stem color with less pitting for both ‘Bing’ and ‘Rainier’ cherries.     

IRRADIATION AS AN ALTERNATIVE TO METHYL BROMIDE FOR QUARANTINE TREATMENT OF STONE FRUITS1

Irradiation can be used with cherries, apricots, or peaches as a quarantine treatment at 300gy's or less with little quality loss. Either irradiation or methyl bromide (MeBr) can be used as a quarantine treatment for ‘Bing’‘and ‘Rainier’ sweet cherries with acceptable results and similar fruit quality. Difference in stem condition and bruising were more evident for irradiated ‘Rainier’ cherries than for MeBr treated ‘Rainier’ cherries, but these differences were small. Use of irradiation results in some firmness loss, for ‘Bing’ cherries when compared with MeBr, but irradiation treatment of cherries does not result in a loss of fruit and stem color, where the use of MeBr doses result in both fruit and stem color loss. Apricots (‘Perfection’ and ‘Rival’) and peaches (‘Regina’) are tolerant to irradiation at 300 gy with little quality loss. Loss of firmness, color changes and increased internal breakdown are evident in both apricots and peaches at irradiation dose above 600 gy. If irradiation dose above 600 gy is required to meet quarantine requirements unacceptable qualidy loss will occur in cherries, apricots and peaches.     

Main quality attributes and antioxidants in Hungarian sour cherries: identification of genotypes with enhanced functional properties

Sour cherry (Prunus cerasus L.) cultivars native to Hungary and some of them grown worldwide, display great phenotypic variability. Eleven sour cherry cultivars were analysed for their main quality attributes including fruit weight, soluble solid content, acidity, pH, specific sugars (glucose and fructose), antioxidant capacity as well as total polyphenolic (TPC), total anthocyanin (TMAC) and vitamin C contents. Results showed wide variation in both fruit quality and antioxidant parameters of Hungarian sour cherries. The anthocyanin contents varied from 11.3 to 93.5 mg/100 g. An amarelle‐type cultivar, ‘Pipacs 1’ showed the highest antioxidant capacity (21.85 mmol AA L^?1), TPC (49.04 mg GA L^?1) and vitamin C (8.98 mg/100 g) content. Key enzymes in anthocyanin biosynthesis were expressed in both yellow‐coloured flesh and red skin of ‘Pipacs 1’ fruits at all ripening stages. The detected diversity presents a choice that can satisfy different consumer preferences, and meet specific nutritional requirements.     

Hot water and curing treatments reduce chilling injury and maintain post-harvest quality of 'Valencia' oranges

‘Valencia’ oranges [Citrus sinensis (L.) Osbeck] were harvested at optimal maturity and either dipped in hot water at 53 °C for 3 or 6 min or at 48 °C for 12 min or cured at 53 °C for 1 or 6 h or at 48 °C for 12 h. The fruits were not degreened, waxed or treated with any post‐harvest fungicides. All fruit samples were stored at 4 °C for 6 months following the treatments. Both hot water dip and curing treatments reduced chilling injury and decay when compared with the untreated control. The most effective treatments were curing of fruit at 53 °C for 6 h and at 48 °C for 12 h. Weight loss and juice yield were higher in cured fruits than those from other treatments, but the heat treatments had no consistent effects on titratable acid, soluble solids, ascorbic acid and peel colour. It was concluded that a pre‐storage hot water dip and curing at high temperatures might be beneficial in preventing chilling injury and decay of ‘Valencia’ oranges for 6 months of storage at 4 °C.     

Bioactive components in forced sweet cherry fruit (Prunus avium L.), antioxidative capacity and allergenic potential as dependent on cultivation under cover

Five early maturing varieties of Prunus avium L. on dwarfing rootstock were forced at Bonn, Germany in spring under transparent plastic cover without additional heating to ripen at a time before field-grown German fruit become available, with better fruit quality than imported sweet cherries; trees grown outside without cover served as control. The cover reduced the incident radiation by up to 54% PAR, UV by up to 22% UV-A and UV-B up to 2% and increased day temperature indoors. Fruit were as firm in the early varieties grown under cover as those in the field and slightly softer than in the late harvesting cultivars. Sugar content was slightly less in four of the five varieties; no differences in acidity and sugar/acid ratio as a taste indicator were found. Fruits were up to 3 mm larger when grown under cover in cvs. ‘Burlat’ and ‘Souvenir’, but no differences were observed in cvs. ‘Earlise’ and ‘Prime Giant’. Fruit of three cultivars, ‘Burlat’, ‘Samba’ and ‘Prime Giant’ can be classified as premium quality with 28 mm–30 mm diameter, when grown under cover. Overall, all cherry fruit were of the market, i.e. consumer- preferred, dark red colouration in line with enhanced anthocyanin contents. In two cultivars, the cover induced healthier fruit. Antioxidative capacity was larger in cv. ‘Samba’, while ascorbic acid (Vitamin C) was increased in cv. ‘Souvenir’; phenols were enhanced in all cultivars and attributed to heat stress. Allergenic protein (Pru av 1) in cherry fruits of both cultivation types were below the detection level at harvest time, indicating that cultivation under cover had no adverse effects on this particular health component.Overall, forcing successfully resulted in 2 weeks earlier ripening, thereby providing the first fresh and healthy (low allergen, high phenolic compounds and high anthocyanin) German cherries of high fruit quality on the market in spring.     

Surface treatments and coatings to maintain fresh‐cut mango quality in storage

BACKGROUND: Edible coatings may extend fresh‐cut fruit storage by preventing moisture loss and decreasing gas exchange. This study evaluated the effect of an antibrowning dip (calcium ascorbate, citric acid and N‐acetyl‐L ‐cysteine), followed or not with carboxymethylcellulose (CMC) or carrageenan coatings on quality of fresh‐cut mangoes stored at 5 °C for up to 20 days. A fourth treatment, only used in one of four experiments, consisted of chitosan. Treatments were applied on ‘Tommy Atkins’, ‘Kent’ and ‘Keitt’ mangoes harvested from Homestead (FL), and on imported store‐bought mangoes. RESULTS: The antibrowning dips maintained the best visual quality during storage for all cultivars, as indicated by higher b*, hue and L*. The CMC coating maintained similar visual quality, but carrageenan or chitosan decreased L* and b*. The antibrowning dip containing calcium ascorbate reduced firmness loss on cut pieces of ‘Keitt’, ‘Kent’ and store‐bought mangoes. The antibrowning treatment maintained higher titratable acidity for ‘Kent’ and ‘Keitt’, resulting in lower sensory sweetness. CONCLUSION: This study with repeated experiments showed that calcium ascorbate with citric acid and N‐acetyl‐L ‐cysteine maintained cut mango slices attractiveness in storage by keeping light color in both varieties. The addition of a polysaccharide coating did not consistently improve quality. Published in 2010 by John Wiley & Sons, Ltd.     

Effects of variety and stage of fruit ripeness on the physicochemical and sensory characteristics of deep‐fat‐fried banana chips

The quality of banana chips prepared from two different varieties of banana, Pisang Abu and Pisang Nangka, at the ‘green’ and ‘trace of yellow’ stages of ripeness was studied. The fruits were peeled, sliced to a thickness of 2 mm and deep‐fat fried in refined, bleached and deodorised (RBD) palm olein at 180 ± 5 °C for 3 min. The quality parameters determined for fresh bananas were total soluble solids, pH, acidity, carbohydrate, sugar content, fat, protein, moisture content, ash, fibre, colour and fruit firmness. The results showed that Abu had a higher carbohydrate content than Nangka at both stages of ripeness before frying. No sucrose was detected in Nangka. The quality parameters determined after deep‐fat frying were moisture content, water activity, oil absorption, crispness and sensory evaluation. The moisture content and water activity of Abu chips were lower than those of Nangka chips. The texture of chips prepared from Abu at stage ‘green’ showed more crispness than the other three samples. Sensory evaluation showed that chips prepared from Abu at both stages of ripeness presented better colour, flavour, odour, texture and overall acceptability than those prepared from Nangka. Based on the matrix of correlation coefficients, fresh bananas with higher fruit firmness and carbohydrate content gave banana chips with higher crispness and oil absorption. © 2001 Society of Chemical Industry     

Use of modified atmospheres to prolong the postharvest life of Burlat cherries at two different degrees of ripeness

The effects of degree of ripeness and packaging atmosphere on the quality of the very early season cherry (Prunus avium) cultivar ‘Burlat’ have been studied. Cherries were classified into two groups depending on their stage of ripening, taking colour as a maturity index (red and purple). After rapid chilling, cherries were sealed in 50 µm low‐density polyethylene (LDPE) bags in four different atmosphere compositions. Packages were stored at 2 °C and cherries were analysed weekly until they were deemed to be commercially unacceptable (after 4 weeks for red cherries and 3 weeks for purple cherries). Changes in atmosphere composition, skin colour, pigment content, titratable acidity, soluble solids, firmness and sensory quality were monitored. Acceptability was higher for the less mature group of cherries. Colour shifted in both groups, initially from red to blue/red and later on back to red. Titratable acidity decreased at the end of the experimental period for all samples. Firmness increased at first, but towards the end of the experiment it was similar to the initial value. The gas composition of the four modified atmosphere conditions approached a final equilibrium consisting of 9–12% CO₂ and 1–3% O₂. For long‐distance transportation of Burlat cherries the following procedure is recommended: harvest at the red colour stage, package in air using LDPE bags and maintain the temperature at 2 °C. Under these conditions, red Burlat cherries can be kept in an excellent commercial state for 3 weeks. © 2000 Society of Chemical Industry     

EFFECT OF POSTHARVEST HOT AIR AND FUNGICIDE TREATMENTS ON THE QUALITY OF 'MARADOL' PAPAYA (CARICA PAPAYA L.)

Papaya (Carica papaya L.) fruit is very perishable with a maximum postharvest life of 4 weeks. The effect of forced moist (100% RH) or dry (50%) hot air with or without Thiabendazole (TBZ at 1.2 g active ingredient/L) on the chilling injury (CI), fungi development and quality of ‘Maradol’papaya fruit stored at 5C or 20C for up to 42 days was investigated. Moist hot air at 48.5C or 50C for 4 h caused fruit injury. Dry air at 48.5C for 4 h, alone or in combination with TBZ, decreased CI intensity and fungi development, and the best effect was achieved by combining dry heat treatment and TBZ, without causing negative effects on fruit quality and without causing heat injury. Hot air treatment, especially in combination with TBZ, decreased growth of inoculated Colletotrichum gloeosporioides. Trehalose was not detected in papaya, probably due to the presence of trehalase. Hot water treatment, with or without TBZ, did not cause any negative effect on the content of β-carotene and lycopene.     

STORAGE OF ‘SWEETHEART’ CHERRIES IN SEALED PLASTIC FILM1

‘Sweetheart’ cherries were sealed in perforated or nonperforated polyethylene bags and stored for 6 weeks in air at 0C. Samples were removed after 1, 2, 4 and 6 weeks of storage and evaluated for fruit and sensory quality. Volatile analyses were done on samples kept in storage for 2, 4, 6, 8 and 9 weeks. Atmospheres after 6 weeks of storage were approximately 4.6% O₂ and 10% CO₂ for the perforated bags (1993) and 6.6% O₂ and 3.5% CO₂ for the non-perforated bags (1994). Fruit brightness (L* value), firmness and titratable acidity declined during storage. Skin color (hue angle) decreased slightly in redness over the 6-week storage period. Sensory evaluation in 1993 showed a decline in fruit appearance and flavor with storage duration. Texture and juiciness did not change. Acceptability remained high for the first 4 weeks of storage. Twenty-seven volatiles were identified by head-space analysis (1993). Little change occurred in volatile production except for acetaldehyde which increased sharply from week 2 to 4 and ethanol which increased sharply between week 8 and week 9. Butyl acetate behaved much like acetaldehyde. Modified atmosphere packaging maintained high fruit luster and green stems. No differences in fruit quality were observed with bag type, but storage appears to be limited to 4 weeks for ‘Sweetheart’ cherries because of flavor loss.     

Maintenance of postharvest quality and bioactive compounds of fresh‐cut sweet leaf bush (Sauropus androgynus L. Merr.) through hot CaCl2 dips

The effects of hot CaCl₂ dips on postharvest quality and bioactive compounds of fresh‐cut sweet leaf bush were investigated. The vegetable was dipped in 0.5% or 1.0% (w/v) of CaCl₂ solutions at 40 °C for 30 s and the control was the untreated sample. Hot CaCl₂ dips significantly delayed the weight loss, maintained the overall quality and inhibited the wiltness (P < 0.05). Both hot CaCl₂ dips had no effect on the changes in lightness (L*) and delayed the decrease in greenness (‐a*) and total chlorophyll content and the increase in both yellowness (b*) and carotenoid content. Hot CaCl₂ dips enhanced total antioxidants, total phenolics content and both AsA‐POD and G‐POD activities from 38.6, 0.44, 15.2 and 22.4 at day 0 to 55.3, 0.55, 50.5 and 362.4 at day 8, respectively. Moreover, hot CaCl₂ dips also delayed the loss of DPPH free radical scavenging activity, total flavonoid, ascorbic acid and CAT activity when compared to other treatments during storage. This study showed that hot CaCl₂ dip maintains postharvest quality and enhanced bioactive compounds of fresh‐cut sweet leaf bush during storage.     

Effect of heat treatment and individual shrink packaging on quality and nutritional value of bell pepper stored at suboptimal temperature

The goal of this study was to develop a technology for prolonged storage of pepper fruit at low temperature, based on physical treatments and packaging materials. Physical and compositional changes of red bell pepper fruit (Capsicum annuum L. cv.’Selika’) were monitored during 21 days of cold storage (at 2 °C) plus 3 days at 20 °C (market simulation). Fruits were treated with tap and hot water and stored without packaging or sealing each fruit in individual shrink packaging (Cryovac®). This research revealed that individual shrink packaging following prestorage with hot water rinse (55 °C for 15 s) over brushes, significantly reduced weight loss, softening, decay incidence and chilling injury, while maintaining a quality. The wrapped fruit ripened normally (carotenoid content increased) during shelf‐life period, when shifted to 20 °C after unwrapping. This study showed that antioxidant levels of pepper fruit may be preserved during storage.     

Enhancing microbiological safety of fresh orange juice by fruit immersion in hot water and chemical sanitizers.

Trials were conducted with hot water and chemicals to sanitize Valencia oranges contaminated by natural microflora or inoculated with Escherichia coli. Microbial loads and sensory quality of fresh juice extracted from surface-heated fruit were also evaluated. E. coli on fruit surfaces was reduced by either hot water or chemical treatments. An estimated 5-log reduction of E. coli was attained by immersing inoculated fruit in hot water at 80 degrees C for 1 min or 70 degrees C for 2 min. Immersing inoculated fruit in various chemical solutions at about 30 degrees C for 8 min only reduced E. coli by about 1.8- to 3.1-log cycles on nonstem-scar surfaces of the fruit. In general, both hot water and chemical treatments were less effective at removing microflora from the stem-scar area. Rapid hot-water immersions at 80 degrees C for 1 min and 70 degrees C for 2 min reduced both fruit-surface and initial juice microbial loads without altering original sensory quality of fresh juice.     

Hot water bath treatments assisted by microwave energy to delay postharvest ripening and decay in strawberries (Fragaria × ananassa)

BACKGROUND: A lab‐scale approach using microwave (MW)‐assisted hot water treatments was developed and tested to assess the potential of this heating method to delay postharvest ripening and decay in strawberries. Strawberries (Fragaria × ananassa) immersed in water were exposed to microwaves at a frequency of 2450 MHz for 3 min at 514 W or 1 min 50 s at 763 W to reach an average temperature of 43.8 ± 0.6 °C at the fruit centre. Another batch was treated in hot water at 45 °C for 15 min, and a final batch was not treated (control). RESULTS: After 9 days of refrigerated storage (3 °C and 90% relative humidity), all heat‐treated strawberries showed significant retention of quality parameters such as colour and firmness and significantly lower yeast and mould populations (P < 0.05). CONCLUSION: Strawberries subjected to MW‐assisted hot water treatments showed significantly better retention of lightness compared with conventionally treated berries. A short (1 min 50 s) treatment at 763 W was the best choice to prevent strawberry decay. Copyright © 2011 Society of Chemical Industry     

Methods for quality evaluation of sweet cherry

Sweet cherry (Prunus avium L.) is a highly valued fruit, whose quality can be evaluated using several objective methodologies, such as calibre, colour, texture, soluble solids content (SSC), titratable acidity (TA), as well as maturity indexes. Functional and nutritional compounds are also frequently determined, in response to consumer demand. The aim of the present review is to clarify and establish quality evaluation parameters and methodologies for the whole cherry supply chain, in order to promote easy and faithful communication among all stakeholders. The use of near-infrared spectroscopy (NIRS) as a non-destructive and expeditious method for assessing some quality parameters is discussed. In this review, the results of a wide survey to assess the most common methodologies for cherry quality evaluation, carried out among cherry researchers and producers within the framework of the COST Action FA1104 ‘Sustainable production of high-quality cherries for the European market’, are also reported. The standardisation of quality evaluation parameters is expected to contribute to the preservation and shelf-life extension of sweet cherries, and the valorisation of the whole supply chain. For future studies on sweet cherry, we put forward a proposal regarding both sample size and the tests chosen to evaluate each parameter. © 2022 Society of Chemical Industry.     

SELECTION OF CHEMICAL AND THERMAL PRETREATMENT COMBINATION TO REDUCE THE DEHYDRATION TIME OF SOUR CHERRY (Prunus cerasus L.)

Sour cherry (Prunus cerasus L.) is a good source of anthocyanins showing antioxidant and anti‐inflammatory activities. Contemporary drying processes of fruits and vegetables should be fast and at relatively low drying temperatures to minimize the energy consumption and the thermal degradation of their nutritional composition. Therefore, sour cherries placed into sample bags were dipped in one of eight different pretreatment combinations consisting of chemical solutions (2% ethyl oleate, 2% K₂CO₃, 1% citric acid or water) and dipping temperature (23 or 60C) for 1 min to accelerate the skin moisture diffusivity by breaking down the waxy cuticular surface of sour cherry. Pretreated sour cherry samples were dehydrated by three different methods (artificial drying, solar drying and open sun drying). Sour cherries treated with 2% ethyl oleate solution at room temperature (23C) were the fastest to reach the final weight loss percentage (75%). They dried in 24 h in the laboratory tray dryer providing 45.2C drying air. The untreated samples reached the same weight loss percentage of 75% at a drying time of 92 h. A high dipping temperature (60C) eliminated the positive effect of ethyl oleate. Solar drying and open sun drying of sour cherries treated with 2% ethyl oleate at room temperature finished approximately in 149 h and 372 h, respectively. The color of dried sour cherries was used as a quality indicator. The increase of dehydration time decreased redness values as seen in solar drying and open sun drying. The recommended pretreatment and drying processes for sour cherries are dipping them into 2% ethyl oleate solution at room temperature for 1 min and then drying them artificially at 45.2C air temperature to effectively retain their original color.     

EFFECTS OF PEEL ADDITION AND STORAGE ON QUALITY OF GOLDEN APPLE (SPONDIAS CYTHEREA SONN) HOT SAUCES

Fresh, frozen or brined golden apple puree (Spondias cytherea) was utilized in hot sauces. The effects of puree, fruit peel addition, and storage on quality of sauces was investigated. Base formulation, (%) consisted of golden apple puree (50), water (25), vinegar (10), peppers (6), sucrose (4) aromatic spices (2), citric acid (1.1) sodium chloride (1.0), xanthan gum (0.8) and sodium benzoate (0.1). Processing of hot sauces was at85–90C for15–20 min followed by hot‐filling into glass bottles. Fruits were acceptable in 20% brine up to 6 weeks at28–31C. Physico‐chemical quality of sauces varied due ( >P <0.05) to fruit puree. Sensory quality did not vary (< P >0.05) in sauces with 0% or 5% peel, however, sauces of 100% peel were more yellow ( P <0.05), had lower total soluble solids ( P <0.05) and were less acceptable ( P <0.05). The shelf‐life of sauces was at least 90 days at28–31C or 5C.