Clingstone Peach Research Articles

Isolation of Polyphenols from Two Waste Streams of Clingstone Peach Canneries Utilizing the Cloud Point Extraction Method

This study aimed to assess the feasibility of employing cloud point extraction (CPE) as an efficient way of extracting polyphenols from peach waste (PW). Four distinct food-grade surfactants (Genapol X-080, PEG 8000, Tween 80, and lecithin) were evaluated at concentrations ranging from 2–10% w/v to determine the efficiency of the technique in two separate PW streams [i.e., lye peeling waste stream (LPWS) and total wastewater stream (TWS)]. Low amounts (2% w/v) of surfactants in a single-step CPE were found to result in less than ~61% polyphenol recovery in LPWS and less than ~69% polyphenol recovery in the TWS, necessitating additional extraction steps. In both PW streams, the single-step polyphenol recovery was improved by 25–67% utilizing a higher amount of surfactants (5–10% w/w), leading to a statistically significant figure (p < 0.05). The CPE procedure was conducted under optimal conditions, including a temperature of 65 °C, a sodium chloride concentration of 3% w/v, a pH level of 3.5, and a surfactant concentration of 5% w/v. The polyphenol recovery was efficient when the CPE procedure was conducted twice. Tween 80 proved to be the most efficient surfactant among the four tested surfactants, achieving recoveries above 98% in both PW streams. Under optimum extraction conditions, the total polyphenol content and antiradical activity of PW extracts were evaluated. The results showed statistically significant differences (p < 0.05) between the two PW streams, with the LPWS having approximately 12 times higher polyphenol content and being more potent, achieving ~64% antiradical activity. Using the LPWS instead of the TWS is a more cost-effective and feasible option for the industry. In addition, the considerable volume of the TWS makes it challenging to handle and demands a correspondingly major amount of surfactant. Considering that Tween 80 is a low-toxicity surfactant and that the CPE method is simple, fast, cost-effective, highly accurate, and selective, the extracted polyphenols from two PW streams could be exploited as natural antioxidants to be used directly in the food industry. These findings could have major implications for the manufacturing of sustainable and naturally-derived food additives.

Nutrient inputs and outputs in commercial clingstone peach orchards in Greece based on conventional or sustainable fertilization practices

Nutrient inputs and outputs in commercial clingstone peach orchards in Greece based on conventional or sustainable fertilization practices

Development of an innovative smart-farming and decision-support service to improve clingstone peach cultivation

Development of an innovative smart-farming and decision-support service to improve clingstone peach cultivation

Profiling carotenoid and phenolic compounds in fresh and canned fruit of peach cultivars: Impact of genotype and canning on their concentration

Peach (Prunus persica (L.) Batsch) is widely consumed both fresh and processed. Scarce information exists regarding the fate of phytochemicals after the peach canning process. The aim of the current study was to evaluate the compositional variability and impact of processing on the bioactive compounds profile of eight non-melting peach cultivars, both in fresh and canned forms, thermally processed with either light syrup (LS) or grape juice (GJ) as the packing medium. LC–MS analysis demonstrated that the phytochemical profile is primarily genotype dependent. Prediction profile statistics revealed that cv. ‘Andross’, a predominant clingstone peach cultivar, possessed the highest desirability score among all the examined cultivars. Free zeaxanthin and lutein remained relatively unaffected by the canning process compared to free β-carotene, whereas soluble phenolic compounds, such as neochlorogenic acid, chlorogenic acid, procyanidin B1 and catechin, showed a large decrease following canning. Using GJ, an additional source of polyphenols, as packing medium led to a reduction of losses for the bioactive compounds. Overall, the experimental findings demonstrated that, besides the thermal degradation of some sensitive to heating compounds, there is a bidirectional flow of the bioactive compounds between the fruit tissue and the liquid matrix, as balanced out by diffusion processes.

The effect of genotype and storage on compositional, sensorial and textural attributes of canned fruit from commercially important non-melting peach cultivars

Peach (Prunus persica) fruit is widely consumed, both as fresh or as processed (mostly by canning) product. Despite its economic importance, a limited number of studies have dealt with quality assessment of clingstone peach cultivars after thermal processing. Thus, the aim of the current study was to evaluate the effect of canning process on compositional, sensorial and textural attributes of fruit from seven non-melting peach cultivars which exhibit on-tree ripening in succession, spanning from July till mid-September in the northern hemisphere. Descriptive quantitative analysis indicated discrete varietal differences, providing useful insights for the industry regarding the quality and marketing potential for canned products of each cultivar. Fruit packed in diluted-clarified grape juice concentrate, aiming towards a less caloric content product, demonstrated an inferior consumer perception regarding bitterness, astringency and off-taste. Storage of the canned fruit (6 versus 24 months) led to texture depletion modifications on a cultivar-dependent manner. ‘Ferlate®’ registered desirable textural properties, while ‘Mirel®’, besides the appealing orange-coloured fruit pieces, aligned with satisfactory sensorial properties, provide further marketing options for the peach canning industry. Both early (‘Romea’) and late-season ripening (‘VLG’) cultivars were proven amenable to canning with acceptable quality attributes, offering a sustainable solution towards extension of the non-melting peach harvesting season.

Population-scale peach genome analyses unravel selection patterns and biochemical basis underlying fruit flavor

A narrow genetic basis in modern cultivars and strong linkage disequilibrium in peach (Prunus persica) has restricted resolution power for association studies in this model fruit species, thereby limiting our understanding of economically important quality traits including fruit flavor. Here, we present a high-quality genome assembly for a Chinese landrace, Longhua Shui Mi (LHSM), a representative of the Chinese Cling peaches that have been central in global peach genetic improvement. We also map the resequencing data for 564 peach accessions to this LHSM assembly at an average depth of 26.34× per accession. Population genomic analyses reveal a fascinating history of convergent selection for sweetness yet divergent selection for acidity in eastern vs. western modern cultivars. Molecular-genetics and biochemical analyses establish that PpALMT1 (aluminum-activated malate transporter 1) contributes to their difference of malate content and that increases fructose content accounts for the increased sweetness of modern peach fruits, as regulated by PpERDL16 (early response to dehydration 6-like 16). Our study illustrates the strong utility of the genomics resources for both basic and applied efforts to understand and exploit the genetic basis of fruit quality in peach.

‘Vilmos’ Peach: A New and Improved “Stay-ripe” Processing Clingstone Peach Ripening in the ‘Andross’ Maturity Season

‘Vilmos’ Peach: A New and Improved “Stay-ripe” Processing Clingstone Peach Ripening in the ‘Andross’ Maturity Season

‘Kader’ Peach: A Processing Clingstone Peach with Improved Harvest Quality and Disease Resistance, Ripening in the ‘Dixon’ Maturity Season

‘Kader’ Peach: A Processing Clingstone Peach with Improved Harvest Quality and Disease Resistance, Ripening in the ‘Dixon’ Maturity Season

The use of rapid FT-NIR methods to predict soluble solids, pH, titratable acidity and phenols of clingstone peaches (‘Baby Gold 9’)

The use of rapid FT-NIR methods to predict soluble solids, pH, titratable acidity and phenols of clingstone peaches (‘Baby Gold 9’)

Influence of plum rootstocks on agronomic performance, leaf mineral nutrition and fruit quality of ‘Catherina’ peach cultivar in heavy-calcareous soil conditions

The agronomic performance and leaf mineral nutrition of the non-melting clingstone peach cv. ‘Catherina’ was evaluated on seven hexaploid plum rootstocks, as well as one Prunus persica seedling. They were assessed over a period of 15 years in a field trial at the Experimental Station of Aula Dei-CSIC (Zaragoza, Spain), located in the Ebro Valley (NE Spain). Growing conditions generated varying levels of tree mortality, the highest with Constantí 1, Monpol and Montizo, whereas all Adesoto, GF 655/2 and PM 105 AD trees survived well. GF 655/2 and P. Soto 67 AD proved to be the most dwarfing rootstocks, while Constantí 1 and Monpol were the most invigorating and generated greater cumulative yields. However, the highest yield efficiency was recorded on GF 655/2 and Montizo, although they did not differ significantly from Adesoto and P. Soto 67 AD. The highest average values for fruit weight were observed on PM 105 AD and the lowest on GF 655/2, but they did not differ significantly from the rest of the rootstocks. The highest average values for the soluble solids content was observed on the Pollizo rootstocks Adesoto and PM 105 AD, followed by P. Soto 67 AD. All rootstocks induced N deficiency, with the exception of Constantí 1, GF 655/2 and Montizo, and iron deficiency, except PM 105 AD. The invigorating rootstock Constantí 1 seems to induce higher SPAD values. According to the ΣDOP index, Montizo presented the most suitable balanced nutritional index, but it did not differ significantly from the rest of the rootstocks except GF 655/2 and P. Soto 67 AD.

The effect of high pressure processing on clingstone and freestone peach cell integrity and enzymatic browning reactions

Abstract HPP-treated fruits and vegetables may undergo undesirable enzymatic browning reactions due to loss of membrane permeability and sub-cellular compartmentalization. Clingstone and freestone peaches were treated from 100 to 500 MPa for 10 min and evaluated for polyphenol oxidase (PPO) activity, color, total phenols, and for cell integrity using light microscopy and 1 H NMR. Significant changes in membrane integrity following HPP above 200 MPa were determined by T 2 shifts in the vacuolar compartment from initial levels of 0.79 (clingstone) or 0.88 (freestone) to approximately 0.60–0.68. Clingstone peaches treated at 300, 400 and 500 MPa showed significant decreases (5, 12 and 7%) in % water of the vacuolar compartment and simultaneous increases in the cytoplasmic compartment (4, 8 and 5%). Additionally, there was a reduction in the number of viable cells from an initial 57–58% to 0 and 14% in clingstone and freestone peaches, respectively. These results correlated with the development of increased browning. Industrial relevance Clingstone peaches are firm-textured and therefore are preserved primarily through canning, which desirably softens the texture. In this study we evaluated the use of high pressure processing – at a range of MPa levels – for preservation, and found that enzymatic browning took place after 2 weeks in refrigerated storage if processing occurred above 200 MPa. Analytical tools were developed to follow the onset of the browning, and in future work preventative measures will be studied to minimize this reaction.

KAOLIN EFFECT ON FRESH AND CANNED CLINGSTONE PEACH FRUIT QUALITY AND INORGANIC ELEMENT COMPOSITION

Recently, kaolin sprayable materials are studied and used with many crops to control insects and diseases, alleviate heat stress and reduce sunburn damage. Furthermore, kaolin has been found to positively affect fruit external and internal quality with various fruit species. We investigated the effect of kaolin particle film application on fresh and canned clingstone peach fruit quality and inorganic element composition. Kaolin was applied periodically from early July to early August 2010 on ‘Andross’ peach trees. Fresh peach fruit treated with kaolin and harvested at commercial maturity (middle of August) had increased flesh firmness (FF), soluble solids content (SSC) and acidity and lower water content (WC) compared to control fruit. Kaolin presence on fresh peach fruit skin did not affect L*, but decreased a* compared to control fruit even after kaolin removal with water. In addition, kaolin-treated fresh peach fruit had similar P, K, Ca, Mg, Fe, Mn, Zn, Cu, Na, Cd, and Ni and slightly lower Pb contents compared to control peach fruit, while Co and Cr were not detected. Canned peach fruit had modified quality compared to fresh fruit, but most of the differences in quality attributes between kaolin-treated and control fruit remained after canning. Peach fruit color was similar in the two treatments after peeling and canning. Finally, the processed peach fruit treated with kaolin had decreased P, K, Mg, Fe, Mn, Zn, Cu, Ni and similar Ca, Na, Cd, Pb contents compared to processed control fruit, while Co and Cr were not detected. It seemed that certain nutrients leaked from the kaolin-treated processed peach fruit to the syrup resulting in decreased SSC and inorganic element content in the processed peach halves compared to the fresh kaolin-treated fruit.

Development of Ty1-copia retrotransposon-based SSAP molecular markers for the study of genetic diversity in peach

Sequence-specific amplified polymorphism (SSAP) technology is a novel, anchored PCR approach derived from AFLP, which amplifies the region between a transposon insertion and an adjacent restriction site and have higher levels of polymorphism. In the current study, we developed 16 SSAP markers based on the long terminal repeat (LTR) sequences of Ty1-copia retrotransposons in the peach and used them for DNA profiling of 52 individual peaches: 44 peach cultivars and 8 ornamental peaches. These primer combinations produced a total of 1,553 fragments and 1,517 polymorphic bands with a polymorphism percentage of 97.7%. Furthermore, the Shannon's information index of each primer combination ranged from 0.1593 to 0.4456. Neighbor-joining analyses revealed two main genetic clusters, corresponding to the fruit flesh types: (A-1) MF (melting flesh) with clingstone and ornamental peaches; (A-2) MF with freestone and NMF (non-melting flesh) with clingstone. Finally, cluster analyses revealed that all ornamental peaches are closely related to the MF with clingstone peach cultivars. The application of these primer combinations identified using SSAP will facilitate future cultivar identification and germplasm management in peaches.

Thermal inactivation of polyphenoloxidase and peroxidase in Jubileu clingstone peach and yeast isolated from its spoiled puree

The thermal inactivation of yeast isolated from spoiled Jubileu peach puree and that of polyphenoloxidase (PPO) and peroxidase (POD) in cv. Jubileu, which is widely cultivated in southern Rio Grande do Sul state, Brazil, were studied. PPO and POD were extracted using the protein powder method and submitted to partial purification by precipitation followed by dialysis. The enzymatic activity was determined measuring the increase in absorbance at 420 nm for PPO and 470 nm for POD. The yeast used in this investigation was isolated from spoiled Jubileu peach puree at 22 °Brix, with total initial microbial count of 22 × 10² UFCmL- 1. Stock cultures were maintained on potato dextrose agar (PDA) slants at 4 °C and pH 5 for later use for microbial growth. In all cases, kinetic analysis of the results suggests that the thermal inactivation was well described by a first-order kinetic model, and the temperature dependence was significantly represented by the Arrhenius law. Both enzymes were affected by heat denaturation, and PPO was more thermostable. PPO was also more thermosTable than the yeast isolated from peach puree. The D60-values were 1.53 and 1.87 min for PPO and yeast isolated from spoiled Jubileu peach puree, respectively.

Characterization and Multivariate Analysis of Physical Properties of Processing Peaches

Characterization of physical properties of fruits represents the first vital step to ensure optimal performance of fruit processing operations and is also a prerequisite in the development of new processing equipment. In this study, physical properties of engineering significance to processing of three popular cultivars of clingstone peaches were evaluated, including dimensional parameters, mass, dimensional ratios, aspect ratio, elongation index, sphericity, bulk density, texture, color, and flavor. Based on these physical properties, multivariate analysis of variance (MANOVA), canonical variate analysis (CVA), principal component analysis (PCA), and partial least squares and linear discriminate analysis (PLS-LDA) were applied to qualitatively and quantitatively discriminate the cultivar difference. Results showed that the studied peach cultivars had significantly different (p < 0.05) geometric characteristics. The peaches can be classified based on the cheek diameter (Dc) into three different size categories, including small- (Dc less than 60 mm), medium- (Dc between 60 mm and 70 mm), and large- (Dc higher than 70 mm) sized peaches. The peach flesh firmness significantly (p < 0.05) decreased with the increase of peach size, while the pit dimensions were independent of peach size. There were no apparent distinctions in color characteristics, bulk density, and sugar content among the three cultivars. The measurements and quantitative discrimination of peach properties in this study would benefit equipment design and process innovation to enhance the processing efficiency and quality of processed peaches.

Effects of infrared radiation heating on peeling performance and quality attributes of clingstone peaches

Salinity and wastewater disposal problems associated with the conventional wet-lye method for peeling clingstone peaches result in considerable negative environment impacts. The efficacy of using infrared (IR) heating as an alternative method for peach peel removal was investigated to eliminate the use of water and chemicals. Peaches sorted into three size categories were double-sided heated under IR with three emitter gaps for a range of heating times from 90 s to 180 s. Wet-lye peeling was used as a control. Results showed that 180 s IR heating for medium sized peaches under an emitter gap of 90 mm yielded 84 mm2/100 mm2 peelability and 90 g/100 g peeling yield, produced peeled products with comparable firmness and color to wet-lye peeled peaches. Surface temperature increased rapidly (> 00 °C) during IR heating whereas the flesh temperature at 16 mm beneath skin remained relatively low (<45 °C). Thermal expansion of cell walls and collapse of cellular layers adjacent to skins were found in IR heated peaches and differed from the micro-structural changes observed in lye heated samples, indicating their mechanistic difference. Promoting uniform and rapid surface heating is essential to further develop IR heating as a non-chemical method for peach peeling.

Nondestructive determination of flesh color in clingstone peaches

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.

Nutritional content of fresh and canned peaches

The objective of this study was to assess whether canned peaches could deliver nutrient levels comparable to fresh peaches. Fresh freestone peaches, fresh cling peaches and canned cling peaches were analyzed for vitamins A, C and E, folate, antioxidants, total phenolics and total carotenoids to assess how these nutrients were affected by the canning process and whether storage further changed these components. The vitamins and phytochemicals measured in this study were found to be present in canned cling peaches versus fresh freestone at statistically significantly higher levels (vitamin C, antioxidants and folate); higher but not statistically different levels (vitamin A); or lower, but not statistically different levels (vitamin E, total phenolics and total carotenoids). There were no statistically significant changes in nutrient content during storage for 3 months. The nutritional content of canned peaches has been shown in this study to be comparable to that of fresh peaches. There were no statistically significant decreases in those nutritional parameters measured in this study between fresh freestone peaches and canned cling peaches. Vitamins A and E along with total carotenoids decrease immediately upon processing, but appear to stabilize after the processing step, showing minimal additional changes upon storage for 3 months. This study shows that canned peaches can provide comparable nutrient levels to the consumer as fresh peaches, meaning that consumers can enjoy peaches year round without worrying about loss of nutrients in their diet.

Phytochemical composition and antioxidant activity of peach as affected by pasteurization and storage duration

Fruit are very perishable and are often preserved as heat-processed foods. Clingstone peach [Prunus persica (L.) Batsch ‘Catherine’] fruit were heat-treated at 90 °C for 5 min and stored under aseptic conditions at room temperature (ca. 22 °C) for 90 days. Significant reductions in total carotenoids were observed immediately after pasteurization but total antioxidant activity and the concentration of total phenolics were unaffected. Pasteurization induced significant reductions in the concentration of protocatechuic acid (from 10.2 to 5.8 μg/g fw), zexanthin and β-cryptoxanthin. Significant reduction in antioxidant activity, expressed as ascorbic acid equivalents, from 0.52 to 0.25 mg/g fw, was observed during storage of pasteurized peach for 90 days. Total phenolics, expressed as gallic acid equivalents, decreased during storage from 0.57 to 0.28 mg/g fw and total carotenoids decreased from 4.0 to 1.3 μg/g fw. Procyanidin B1 increased from 15.8 to 26.8 μg/g fw and chlorogenic acid and neochlorogenic acid increased 35 and 43%, respectively. (−)-Epicatechin decreased during storage from 13.1 to 4.0 μg/g fw and quercetin-3-glucoside from 7.3 to 4.4 μg/g fw. All carotenoids decrease significantly with the exception of zeaxanthin, which increased during storage. Storage duration strongly affected the concentration of phenolics and carotenoids in pasteurized peach.

‘White Diamond’ and ‘White Cloud’ Peaches

‘White Diamond’ and ‘White Cloud’ are the fourth and fifth white-fleshed peach releases from the University of Arkansas peach [Prunus persica (L.) Batsch] breeding program. Prior releases include ‘White River’ (2002) (Clark and Moore, 2003) and ‘White Rock’ and ‘White County’ (2004) (Clark et al., 2005). The program began in the 1960s (Clark et al., 1999) and included an objective to develop adapted white-fleshed peach cultivars for on-farm, local, and shipping sales. This group of cultivars provides for 6 to 7 weeks of adapted white peaches for Arkansas growers and other producers in similar climates. ‘White Diamond’ is a late-season maturity freestone with very firm flesh that softens when fully ripe and is low acid in flavor. ‘White Cloud’ is an early, midseason clingstone with non-melting flesh like that found in processing cling peaches. It has a standard acid flavor. These cultivars have good to very good resistance to bacterial spot [caused by Xanthomonas campestris pv. pruni (Smith) Dye] and should provide high-quality options for growers in areas where bacterial spot disease is a concern. These cultivars also expand options for growers in the midto the upper southern United States and other areas of the world with similar climatic conditions.