The minimum RSSC needed to reach high consumer acceptance for peach and nectarine was determined by using ‘in-store’ consumer tests of low and high RTA melting flesh cultivars as a part of our ...program to develop minimum quality indexes. For ‘Ivory Princess’, a low acid, white flesh peach, ‘Honey Kist’, a low acid, yellow flesh nectarine, ‘Elegant Lady’, a high acid, yellow flesh peach, and ‘Spring Bright’, a high acid, yellow flesh nectarine, degree of liking and consumer acceptance were associated with ripe soluble solids concentration (RSSC) regardless of ripe titratable acidity (RTA). For the two high acid (0.70–0.90% RTA) cultivars tested, consumer acceptance increased rapidly as RSSC increased, reaching ∼90%. In these cultivars, consumer acceptance reached a plateau and above which, it became insensitive to any additional increase in RSSC. For ‘Elegant Lady’ and ‘Spring Bright’, the plateau was reached at 11–12%, and 10–11% RSSC with ∼90% consumer acceptance, respectively. For the low acid cultivars (0.30–0.50% RTA), ‘Ivory Princess’ and ‘Honey Kist’, consumer acceptance progressively increased as RSSC increased without reaching a plateau, and attained nearly 100% acceptance with RSSC of 16 and 15%, respectively.
For these low acid and high acid cultivars, consumer acceptance was closely related to RSSC but maximum consumer acceptance was attained at different RSCC levels depending on the cultivar. The fact that these cultivars reached high consumer acceptance with different RSSC levels indicates that a single generic RSSC quality index would not be reliable to assure consumer satisfaction across all cultivars.
The endoplasmic reticulum has a central role in biosynthesis of a variety of proteins and lipids. Mitochondria generate ATP, synthesize and process numerous metabolites, and are key regulators of ...cell death. The architectures of endoplasmic reticulum and mitochondria change continually via the process of membrane fusion, fission, elongation, degradation, and renewal. These structural changes correlate with important changes in organellar function. Both organelles are capable of moving along the cytoskeleton, thus changing their cellular distribution. Numerous studies have demonstrated coordination and communication between mitochondria and endoplasmic reticulum. A focal point for these interactions is a zone of close contact between them known as the mitochondrial-associated endoplasmic reticulum membrane (MAM), which serves as a signaling juncture that facilitates calcium and lipid transfer between organelles. Here we review the emerging data on how communication between endoplasmic reticulum and mitochondria can modulate organelle function and determine cellular fate.
Chilling injury (CI) is the collective term for various disorders that occur during prolonged cold storage and/or after subsequent ripening of stone fruit. Major symptoms of CI include mealiness, ...graininess, flesh browning, loss of flavor (off flavor), and red pigmentation (bleeding). These symptoms were evaluated over 2 years in an intra-specific progeny population derived from the cross of cultivars ‘Venus’ (freestone, melting and yellow-flesh nectarine) and ‘BigTop’ (clingstone, melting and yellow-flesh nectarine) after storage of fruit at 5
°C (CI inducing conditions) for 2 and 4 weeks. All the evaluated traits in the progeny showed continuous variation which is typical of quantitative or polygenic inheritance. Longer cold storage periods increased the incidence and severity of CI symptoms, except for bleeding and leatheriness, which were not affected by time of storage. CI symptoms showed high and significant heritability or genotype effect in the studied population, with no significant effect of harvesting year. Browning, mealiness and graininess were significantly correlated and were the main CI symptoms observed in this population. Mealiness and graininess were negatively correlated with stone adhesion which reflects the higher susceptibility to CI disorders of freestone fruit. A genetic linkage map of linkage group 4 (LG4) was constructed with SSR and candidate genes (CGs). Significant quantitative trait loci (QTLs) for mealiness, graininess, leatheriness and bleeding were found in this linkage group, validating QTLs for CI symptoms previously reported in this linkage group from an unrelated progeny population. In addition, QTLs controlling other agronomic and fruit quality traits were also localized in this linkage group.
► The effects of 20°C pre-storage on stone fruit quality after cold storage and shelf life were investigated. ► Ester profiles were influenced by pre-storage and fruit cultivar. ► Maximum ester ...emission was found after 36h of pre-storage plus 20 d at −0.5°C. ► Most compounds that contributed to flavour and sweetness were found with the pre-storage treatment.
Pre-storage at 20°C before cold storage was used to improve volatile compound emissions of ‘Big Top’ nectarine and ‘Early Rich’ peach fruit without negatively affecting quality measures and sensory attributes. Commercially harvested fruit were subjected to pre-storage at 20°C for 0, 10, 24, or 36h and then stored at −0.5°C for 10, 20, or 40 d. After cold storage, the fruit were kept at 20°C for up to three days. ‘Big Top’ nectarines given 10h pre-storage followed by 10 and 20 d cold storage were perceived as more flavourful, juicy, and sweet, had higher soluble solid contents, and contained more butyl propanoate, 2-methybutyl-2-methylpropanoate, and 2-methyl-1-butanol than control fruit. ‘Early Rich’ peaches given 36h pre-storage followed by 20 d cold storage were perceived as sweeter and had more propyl acetate, pentyl acetate, and 2-methyl-1-butanol than control fruit.
The aim of this study was to analyze the changes in cell wall pectins in normally ripening (juicy) and in chilling-injured plum fruit (
Prunus salicina cv. Fortune) showing mealiness. Total cell wall ...neutral sugars and uronic acids, solubilization and depolymerization of pectins in water-, CDTA- and Na
2CO
3-soluble fractions of the cell wall (WSF, CSF and NSF, respectively), non-cellulosic neutral sugar compositions of these fractions, and the activities of the cell wall-degrading enzymes polygalacturonase (PG), pectin methylesterase (PME), 1,4-β-
d-glucanase/glucosidase and β-galactosidase (β-gal) were determined. No differences in the total content of pectin and neutral sugars between normally ripening and chilling-injured fruit were detected. However, the mealy plums presented a higher level of tightly bound pectin (NSF) and a lower proportion of loosely bound pectin (WSF) than the juicy controls. Lower pectin depolymerization and reduced solubilization of neutral sugars in the WSF and CSF were also detected in the chilling-injured tissues, confirming an alteration in the normal ripening-associated pattern of polyuronide disassembly. While no differences were found in the activities of PG, PME and 1,4-β-
d-glucanase/glucosidase between normally ripening and mealy fruit, the latter had reduced β-gal activity. This might have led to differential solubilization of polymers with galactan side chains, but further studies are required to determine if there is a causal relationship between these events. Overall, results indicated that the development of chilling injury symptoms in ‘Fortune’ plums is associated with abnormalities in cell wall metabolism, including a reduction in pectin solubilization and depolymerization and decreased ripening-associated modification of galactose-rich pectin polymers.
Current consumer preferences, hand labor costs, and global markets are forcing changes in the breeding, production, and delivery of fresh peaches and processed/ minimally processed peach produce. ...Over the last 20 years, the peach fruit quality concept has evolved from large bright red color fruit to a flavorful, healthy, ready and easy to eat, safe peach with high consumer acceptance. Breeding efforts using new genetic pools are being carried out to develop peaches that ripen uniformly in the canopy with diverse predominant visual, shape, flavor, and texture attributes; and physiological traits at ripening that are adapted to minimal processing. The peach genotype and phenotype expression diversity, especially related to flesh softening, ethylene production, browning development, and wound responses, can be utilized for prolonging storage/shelf life and minimally processed products. For example, different melting level types (none, soft, firm, very-very firm), slow ripening (SR), and stony hard (SH) genotypes are interesting biological sources for the ready-to-eat produce concept. Because of recent advances in new nondestructive sensor technology and the long-term lack of peach flavor in the market, there is high interest for using nondestructive sensors online to segregate fruit according to their postharvest/shelf life potential and consumer acceptance. However, the use of nondestructive sensor technology to segregate cultivars prior to consumption should be focused on flavor and loss of flavor. Furthermore, consumers should be willing to pay a premium to justify the extra cost of using any new nondestructive sensor technology.
A postharvest application, by immersion, of a new 1-methylcyclopropene (1-MCP) formulation delayed ripening changes and extended the shelf life period of plum fruit (
Prunus salicina Lindell cv. ...Joanna Red) harvested at an advanced maturity stage when ripened immediately after harvest or after cold storage. Fruit were either immersed in a water solution (control) or in an aqueous solution of a formulation containing 10, 100, 1000 and 10,000
ng
kg
−1 of 1-MCP. The fruit were allowed to ripen at 23
°C after 5-m immersion or after immersion and subsequent cold storage (5
°C, RH 90%) for 10
d, prior to being evaluated for quality attributes. 1-MCP immersion treatments reduced firmness loss, skin color changes, fruit weight loss and respiration rate. Furthermore, a pronounced suppression of ethylene production in fruit treated with 1000 and 10,000
ng
kg
−1 1-MCP was detected. All fruit ripened normally and did not show any chilling injury (CI) symptoms when ripe fruit were evaluated after cold storage. Overall, 1-MCP concentration of 1000
ng
kg
−1 was the most effective in controlling fruit ripening changes and extending the shelf life of this advanced maturity (tree ripened), low CI susceptible plum. This is the first study, to the best of our knowledge, reporting the successful application of 1-MCP by immersion on the postharvest performance of fleshy fruit.
► Skin color was uncorrelated to flesh color in peaches with skin hue angles below 70°. ► Mean flesh reflectance at 675nm (chlorophyll band) was related to flesh hue only for higher hues. ► Skin ...reflectance was not needed when predicting flesh hue by interactance measurements. ► Nondestructive interactance at two visible wavebands can predict peach flesh hue (r=0.92).
A nondestructive optical method, based upon visible and near infrared interactance spectroscopy, was developed for rapid determination of flesh color in clingstone peaches. Flesh color is currently used by the Californian canning peach industry as a destructive maturity index for clingstone peaches inspected at harvest and as a predictor of sensory flavor quality. Results show that skin ground color becomes uncorrelated with flesh color for skin ground color hue angles below 70°. Cultivar-specific models using nondestructive, log-transformed, interactance measurements at two wavebands in the visible region produced good predictive performance of flesh hue (r=0.92), while a global model required information at five wavebands to achieve this same level of performance (r=0.92 and RMSECV=1.35° hue). The nondestructive method does not require a separate measurement of skin reflectance and is suitable for flesh color grading tasks at inspection stations prior to canning and shows good potential for on-line sorting tasks.
Modern genetic improvement methods require a high degree of certainty con-cerning breeding pedigrees. In large plant breeding operations, however, this degree of certainty is constantly compromised ...as a result of multiple biological, environmental and human factors. A pedigree correction method based on information from molecular markers, breeding program records and the software package FRANZ, which performs an algorithm for pedigree reconstruction, has been tested, which has allowed a corrected estimation of Breeding Value (BV) for fruit weight through either Bayesian or frequentist approaches. Prior to pedigree correction, segregation distortions were for several accessions observed, which distorted the estimation of genetic parameters. After the pedigree correction, inconsistencies could be identified in approximately 20% of the accessions tested. Several of these accessions appeared to originate from crosses other than those recorded. Subsequently, the corrected pedigree was used for BV estimation, showing that two distinct and mutually exclusive approaches used for estimation yielded similar results, although some inconsistencies arose in the rankings of the most likely parentages.
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