CAPILLARY GAS CHROMATOGRAPHY ANALYSIS OF LIPID COMPOSITION AND EVALUATION OF PHENOLIC COMPOUNDS BY MICELLAR ELECTROKINETIC CHROMATOGRAPHY IN ITALIAN WALNUT (JUGLANS REGIA L.): IRRIGATION AND FERTILIZATION INFLUENCE

ABSTRACT

Rapid analytical techniques were used to analyze the lipid fraction and to characterize phenolic compounds in Italian walnuts (Chandler cv.) grown in the same experimental orchard under different agronomical conditions. Lipid components such as fatty acids, sterols and tocopherols were determined by capillary gas chromatography using a flame ionization detector. Linoleic and linolenic acids were the most representative ω‐6 and ω‐3 essential dietary fatty acids present. A total lipid chromatogram was used to simultaneously determine free sterols and tocopherols. Walnuts contained substantial amounts of γ‐ and δ‐tocopherol, which explains their antioxidant properties. Sitosterol, Δ⁵‐avenasterol and campesterol were the major free sterols found. Micellar electrokinetic chromatography was used to analyze simple and complex phenols (tannin profile), while the total phenol amount and the antioxidant activity of phenolic extracts were assessed by spectrophotometric assays with Folin‐Ciocalteu and ABTS^•+ reagents, respectively. The total phenol content was higher than most foodstuffs. Moreover, more than 96% of the phenolic fraction belonged to the tannin class. Statistical analysis of the data showed that higher levels of nitrogen fertilization led to a significant increase in linoleic acid. This effect can induce a faster oxidation of lipid fraction of walnuts. Nevertheless, major nitrogen fertilization and irrigation were able to enrich walnuts in phenolic compounds.

PRACTICAL APPLICATIONS

Walnuts (Juglans regia L.) are a good source of essential fatty acids, tocopherols and phenolic compounds that contribute to reducing the risk of coronary heart disease, and also inhibit the oxidation of human plasma and low density lipoproteins. In this work, the applicability of fast analytical determinations was utilized to discriminate different walnut samples. Total lipid chromatogram was used for the simultaneous determination of the profile of sterols and tocopherols; micellar electrokinetic chromatography was used for the phenolic separation, which takes less than 10 min. The proposed methods are ideal for routine analysis of the lipidic and phenolic fractions in order to control the quality of walnuts.

     

Phenolic Compounds,Antioxidant Activity,and Medium Chain Fatty Acids Profiles of Coconut Water and Meat at Different Maturity Stages

Coconut is grown in tropical and subtropical areas worldwide. The endosperm (water and meat) is consumed and processed in different forms. This study investigated the antioxidant activities and identified the phenolic compounds existing in the water and meat of coconut fruits at three different maturity stages, i.e., 180, 190, and 225 days after pollination from two planting areas in Thailand. Total phenolic content and antioxidant activity indices increased as the coconut matured from 180 to 190 days after pollination and then decreased or remained unchanged at 225 days after pollination. Catechin and salicylic acid were the major phenolic compounds found in the water, while gallic, caffeic, salicylic, and p-coumaric acids were found in the meat. The fat content of the meat increased significantly with maturity stage. Medium chain fatty acids profiles were also analyzed. The results are important for producers, processors, and consumers to realize an optimal quality and functionality of coconut water and meat when used for specific purposes.     

Nutrient composition of kopyor coconuts (Cocos nucifera L.)

Kopyor coconuts (matured coconuts with broken meat particles in the watery endosperm due to abnormal formation of the kernel during the development of the fruits) were analysed for their proximate composition, minerals, vitamins, dietary fibres, sugars, organic acids, fatty acid composition and amino acid profile. The chief constituent of kopyor water was sucrose (about 92% of the total sugar); in contrast, the young or normal-mature nut water contained glucose and fructose as the main sugars. α-Tocopherol was detectable in the kopyor water. Total amino acid content of kopyor water was higher than that of the young or normal-mature water. Like the young or normal-mature nut water, kopyor water seemed to be a good source of dietary minerals, with potassium as the predominant one.The relatively high contents of sucrose, glucose, fructose, citric and malic acids might contribute to the deliciousness of kopyor meat. The lipid content of kopyor meat was lower than that of the normal-mature meat, but fatty acid profiles were similar.     

温185、新新2号核桃及后代坚果脂肪酸含量比较

为了选育新疆核桃坚果综合品质优良的核桃品种,研究温185和新新2号核桃及后代坚果饱和脂肪酸、不饱和脂肪酸含量,为核桃优良品种栽培及推广提供理论基础。采用索氏抽提法、气相色谱法,测定温185和新新2号核桃及后代坚果中10种脂肪酸组成成分及含量,分析新疆阿克苏核桃实生后代坚果脂肪酸相关指标的变异情况。温185坚果脂肪质量分数为68. 11%,它的实生后代的均值为64.62%,其中温185坚果仁的多不饱和脂肪酸占69. 70%,其实生后代的占72. 39%。新新2号坚果脂肪质量分数为66. 55%,它的实生后代的均值为66.48%,其中新新2号坚果仁的多不饱和脂肪酸占71.01%,其实生后代的占70.95%。新疆温185、新新2号两个核桃品种实生后代脂肪酸含量相对丰富,这为品种改良尤其是高含量的多不饱和脂肪酸的选择性育种提供了良好的种质资源。     

NONTHERMAL STERILIZATION OF GREEN COCONUT WATER FOR PACKAGING

ABSTRACT

A laboratory scale technique for nonthermal sterilization of green coconut water was developed. The process consisted of two‐stage filtrations under constant pressure using different filter media; namely, low ash filter paper (Whatman 42) in the first stage and cellulose nitrate membrane (0.2‐µm pore opening) in the second stage. The quality of the filtered water was evaluated with respect to microbial population, organoleptic characteristics, nutrient contents and physical properties. The water after the second stage of filtration was sterile with no visible growth of microbes on culture plates. The taste of the processed water did not change significantly; however, the flavor and overall acceptability decreased about 9 and 11%, respectively. The water also remained sterile after 1 month in aseptically packed condition, but overall acceptability further decreased by 6%. The filtration reduced different nutrients of the fresh water like fat, ash, total sugar, reducing sugar and protein by 40.0, 43.9, 23.4, 29.2 and 13.3%, respectively; the removal of K, Mg, Ca, Fe and Cu was 10.15, 16.14, 19.04, 20.85 and 22.21%, respectively. The removal of these nutrients increased surface tension and decreased viscosity of the coconut water.

PRACTICAL APPLICATIONS

Packaging of sterile green coconut water as soft drink has a good global market as it ensures its widespread availability, quantity and reasonable price. Non‐thermal sterilization by membrane filtration has been found to be an alternative to thermal sterilization as the later adversely deteriorates many essential qualities of this delicate coconut water. The present non‐thermal sterilization technique maintained the sterility, nutritional quality and desirable organoleptic profile of the processed water. Thus, this process could be applied for production of green coconut water as packaged soft drink.

     

CHANGES IN APPARENT VISCOSITY AND VITAMIN C RETENTION DURING THERMAL TREATMENT OF BUTTERNUT SQUASH (CUCURBITA MOSCHATA DUCH) PULP: EFFECT OF RIPENING STAGE

ABSTRACT

The effects that ripening stage have on the apparent viscosity and ascorbic acid retention in squash pulp exposed at cooking process were analyzed. Total soluble solids contents were taken as indicative of ripening degree. In the raw material, water contents ranged from 79 to 96%, but no significant differences were observed among samples grouped as unripe, ripe and overripe. The ascorbic acid contents of pulp increase with increases in soluble solids contents. Pulp from unripe and ripe squash had similar apparent viscosity values; however, lower viscosity values were obtained in pulp from overripe squash. During heat treatment, significant changes in the apparent viscosity values of pulp from unripe and ripe squash were observed. Heat penetration properties of squash pulp indicate correlation between the inverse slope of the straight portion in the heat penetration curves on a semilog plot (fh) and thermal diffusivity values (α) with dry matter content, but no correlation was found with squash maturity degree. High ascorbic acid retention (82%) in pulp held for 30 min at 95C was found independently of squash maturation degree.

PRACTICAL APPLICATIONS

Knowing the rheological behaviour and the ascorbic acid retention of butternut squash pulp during cooking process could be used as a valuable information previously to make decisions for use this crop as a food supply.

     

Urinary Excretion of Niacin Metabolites in Humans After Coffee Consumption

Scope

Coffee is a major natural source of niacin in the human diet, as it is formed during coffee roasting from the alkaloid trigonelline. The intention of our study was to monitor the urinary excretion of niacin metabolites after coffee consumption under controlled diet.

Methods and results

We performed a 4‐day human intervention study on the excretion of major niacin metabolites in the urine of volunteers after ingestion of 500 mL regular coffee containing 34.8 μmol nicotinic acid (NA) and 0.58 μmol nicotinamide (NAM). In addition to NA and NAM, the metabolites N¹‐methylnicotinamide (NMNAM), N¹‐methyl‐2‐pyridone‐5‐carboxamide (2‐Py), and nicotinuric acid (NUA) were identified and quantified in the collected urine samples by stable isotope dilution analysis (SIVA) using HPLC‐ESI‐MS/MS. Rapid urinary excretion was observed for the main metabolites (NA, NAM, NMNAM, and 2‐Py), with t_max values within the first hour after ingestion. NUA appeared in traces even more rapidly. In sum, 972 nmol h^?1 of NA, NAM, NMNAM, and 2‐Py were excreted within 12 h after coffee consumption, corresponding to 6% of the ingested NA and NAM.

Conclusion

The results indicate regular coffee consumption to be a source of niacin in human diet.

     

Effect of substituting fresh‐cut perennial ryegrass with fresh‐cut white clover on bovine milk fatty acid profile

BACKGROUND

Including forage legumes in dairy systems can help address increasing environmental/economic concerns about perennial ryegrass monoculture pastures. This work investigated the effect of substituting fresh‐cut grass with increasing quantities of fresh‐cut white clover (WC) on milk fatty acid (FA) profile and transfer efficiency of dietary linoleic (LA) and α‐linolenic (ALNA) acids to milk fat. Three groups of three crossbred dairy cows were used in a 3 × 3 crossover design. Dietary treatments were 0 g kg^?1 WC + 600 g kg^?1 grass, 200 g kg^?1 WC + 400 g kg^?1 grass, and 400 g kg^?1 WC + 200 g kg^?1 grass. All treatments were supplemented with 400 g kg^?1 concentrates on a dry matter basis. Cows had a 19‐day adaptation period to the experimental diet before a 6‐day measurement period in individual tie stalls.

RESULTS

Increasing dietary WC did not affect dry matter intake, milk yield or milk concentrations of fat, protein or lactose. Milk polyunsaturated FA concentrations (total n‐3, total n‐6, LA and ALNA) and transfer efficiency of LA and ALNA were increased with increasing dietary WC supply.

CONCLUSION

Inclusion of WC in pastures may increase concentrations of nutritionally beneficial FA, without influencing milk yield and basic composition, but any implications on human health cannot be drawn. © 2018 The Authors. Journal of the Science of Food and Agriculture published by JohnWiley & Sons Ltd on behalf of Society of Chemical Industry.

     

THE QUALITY OF VEGETABLE OIL FROM THREE VARIETIES OF SUNFLOWER SEEDS (HELIANTHUS ANNUUS)

ABSTRACT

Vegetable oils become susceptible to oxidation during their processing. The appropriate extraction and refining conditions of oil from two experimental cultivars (Madero‐91 and Cianoc‐2) of sunflower seeds and a commercial one (Victoria) as a control, were studied. Isopropyl alcohol was used in the extraction and refining, and compared with hexane. The refining was performed by the miscella method at 40, 50, 60 and 70%. Free fatty acids (FFA) and malonaldehyde analysis of crude oils afforded no significant differences among solvents and sunflower varieties. In refined oils, differences found with the miscella concentration, the malonaldehyde content and FFA content were not significant. Cianoc‐2 was the best source for oil production because of its lower values in FFA and malonaldehyde content.

PRACTICAL APPLICATIONS

The use of hexano in refining vegetable oil in Mexico is common, lack of knowledge about the use of new solvents and their impact on the processing conditions with sunflower seed cultivars is lack. The present work describes at lab scale, the work conditions, advantages and posibilities and limitations of the use on isopropyl alcohol in comparison with hexane and the use of three Mexican cultivar with this approach, with emphasize in oxidation conditions of refined vegetable oil.

     

Changes in chemical composition of coconut (Cocos nucifera) water during maturation of the fruit

Changes in chemical composition of coconut (Cocos nucifera) water, including total and soluble solids, titratable acidity (as citric acid), turbidity, ash, lipids and sugars, were investigated in four varieties of coconuts at four stages of maturity of the fruit. The most significant change was observed in the volume of nut water, which increased during development from 233 to 504 ml, with the greatest quantity found at 9 months. Fat, protein, soluble solids, acidity and turbidity also increased steadily with maturity, while pH and ash showed variation throughout maturation. The interaction of variety and stage of maturity of the fruit appeared to have a significant effect on the chemical composition of the coconut water. Copyright © 2004 Society of Chemical Industry     

Clinical and Vitamin Response to a Short‐Term Multi‐Micronutrient Intervention in Brazilian Children and Teens: From Population Data to Interindividual Responses

Scope

Micronutrients are in small amounts in foods, act in concert, and require variable amounts of time to see changes in health and risk for disease. These first principles are incorporated into an intervention study designed to develop new experimental strategies for setting target recommendations for food bioactives for populations and individuals.

Methods and results

A 6‐week multivitamin/mineral intervention is conducted in 9–13 year olds. Participants (136) are (i) their own control (n‐of‐1); (ii) monitored for compliance; (iii) measured for 36 circulating vitamin forms, 30 clinical, anthropometric, and food intake parameters at baseline, post intervention, and following a 6‐week washout; and (iv) had their ancestry accounted for as modifier of vitamin baseline or response. The same intervention is repeated the following year (135 participants). Most vitamins respond positively and many clinical parameters change in directions consistent with improved metabolic health to the intervention. Baseline levels of any metabolite predict its own response to the intervention. Elastic net penalized regression models are identified, and significantly predict response to intervention on the basis of multiple vitamin/clinical baseline measures.

Conclusions

The study design, computational methods, and results are a step toward developing recommendations for optimizing vitamin levels and health parameters for individuals.

     

QUALITY AND STORAGE STABILITY OF CHICKEN MEAT PATTIES INCORPORATED WITH LINSEED OIL

ABSTRACT

Low‐fat (<10% total fat) chicken meat patties (CMP) with different levels of linseed oil (LO) i.e., 0, 2, 3 and 4% (control, T₁, T₂ and T₃) were evaluated for their nutritive, processing, textural and storage qualities. The cooking yield, fat and moisture retention were comparable in control and LO‐treated products. The dimensional parameters were better maintained for T₂ among the LO treatments_. The sensory panelists rated T₂ as the best among treatments with comparable sensory attributes to control patties. The selected 3% level of LO was compared with the control for color, texture and fatty acid profile. The lightness (L*) and redness (a*) values were significantly (P < 0.05) less, whereas yellowness (b*) was significantly (P < 0.05) higher for the developed CMP than the control. The chewiness value was higher in control, whereas firmness and springiness were comparable in both the products. The total saturated fatty acid (SFA) content was significantly (P < 0.05) decreased, whereas α‐linolenic acid increased significantly (P < 0.05) in the developed CMP. The ratio of polyunsaturated fatty acids (PUFAs) and SFAs was increased, whereas n‐6/n‐3 decreased in developed CMP. CMP with 3% LO remained physicochemically and microbiologically stable with some deterioration in sensory attributes during aerobic refrigerated (4 ± 1C) storage of 25 days.

PRACTICAL APPLICATIONS

LO is a rich source of omega‐3 fatty acid and is used in the feed of the meat animals for nutritionally better quality meat, which requires long period of rearing and is costly. However, the direct incorporation of LO in the processed meat products poses various technological problems. Therefore, the efficacy of LO as a partial substitute of vegetable oil in the low‐fat omega‐3‐enriched meat products was assessed. The developed processing technology can be commercially exploited for the development of functional/health‐oriented meat products with low fat and low energy, rich in omega‐3 fatty acid, and balanced in PUFA and SFA ratio.

     

DEVELOPMENT OF A BLENDED NONALCOHOLIC BEVERAGE COMPOSED OF COCONUT WATER AND CASHEW APPLE JUICE CONTAINING CAFFEINE

ABSTRACT

In this work, the stability of a blended beverage composed by coconut water and clarified cashew apple juice (“cajuina”) is presented. The physicochemical, microbiological and sensory stability of a blended nonalcoholic beverage composed of coconut water and cajuina (80:20 v/v) were evaluated during 6 months. The results showed that the beverage presented good stability in all analyzed parameters except for vitamin C, which presented a loss of about 80% of the initial content. The beverage color also presented changes during the storage time. Despite these alterations, the product acceptance during the storage period did not show any rejection.

PRACTICAL APPLICATIONS

The development of blended beverages is a good way of improving the nutritional quality of traditional products. By mixing two or more kinds of fruits, a product with more vitamins and minerals and with different sensory and flavor characteristics when compared to the raw materials is obtained. In the present work, coconut water and cashew apple juice were mixed to obtain a different product combining the nutritional components from both fruits. The blended beverage combines the high vitamin C content of the cashew apple juice with the high mineral level of the coconut water. Caffeine was also added conferring stimulating properties to the product. The product acceptance was evaluated by sensory analysis and presented good acceptance until 6 months of storage at room temperature, presenting the required characteristics for a commercial product.

     

CHANGES IN SOYMILK QUALITY AS A FUNCTION OF COMPOSITION AND STORAGE

ABSTRACT

Three soymilk products formulated with different concentrations of fat, sugar and starch were evaluated for changes in their physical properties and volatiles profile over time (3 months) under different temperatures (4, 22 and 38C) of storage. Samples were tested for pH, color, viscosity and volatile flavor changes. The pH and color of the soymilks decreased significantly during the first month of storage and then remained stable over time. Color and viscosity of the soymilk products were affected by both the soymilk composition and storage treatment. The high‐fat soymilk sample (product C) had the whitest color (lower ΔE) and the lowest viscosity. Storage at 38C negatively affected the color. The viscosities of the soymilk products stored at 4C were the lowest among the treatments. The major volatiles identified in all soymilk products were hexanal, heptanal, octanal, nonanal, hexanol, 1‐octen‐3‐ol, benzaldehyde, 2‐pentyl furan and 2‐ethyl furan. The intensities of the volatile compounds in the soymilk products increased during the first weeks of storage, particularly when stored at 38C. The intensities, however, decreased gradually over time. Among the three formulated soymilk products, the sweetened sample (product B) gave the lowest flavor intensities under all three temperatures of storage. Overall, storage at 4C and addition of sugar preserve best the soymilk quality.

PRACTICAL APPLICATIONS

Soy products are well appreciated for their nutritional and potential health benefits. Soy beverage consumption is increasing among North American consumers because of improvements in soy beverage quality and processing technologies. There is, however, a demand for new value‐added soy‐based drinks with improved “functional” (health‐benefiting) properties. Soy beverage could be an excellent carrier for “functional” or “nutritive” ingredients such as minerals, vitamins and omega 3 oils; however, addition of such ingredients may affect the stability of the product and requires the development appropriate of technologies for their incorporation. Results from this project provide new knowledge on the storage stability and quality of three different soy product formulations. The information could be useful in the establishment of optimal conditions for processing of functional soy beverages, for use by the food industry.

     

Relationship between vitamin D and gestational diabetes in overweight or obese pregnant women may be mediated by adiponectin

Scope

Maternal vitamin D deficiency has been implicated in adverse pregnancy outcomes. However, the association between vitamin D and inflammation, particularly adipokines, remains unexplored in pregnancy.

Methods and results

In 102 overweight or obese pregnant women at high‐risk of gestational diabetes mellitus (GDM), we investigated relationships between maternal 25‐hydroxyvitamin D (25(OH)D) concentrations at 12–15 wk gestation (baseline) and serum lipids, inflammatory markers, novel adipokines (omentin‐1, visfatin, high molecular weight (HMW) adiponectin), and subsequent pregnancy outcomes (GDM, preeclampsia, preterm birth [PTB]). After adjustment for maternal factors (age, BMI, parity, ethnicity, and smoking status), baseline 25(OH)D concentrations were inversely associated with total cholesterol and triglycerides, and positively associated with HMW‐adiponectin. Higher baseline 25(OH)D concentrations were associated with decreased fasting and 1‐h post‐OGTT glucose and reduced risk of GDM at 26–28 wk, as well as with longer gestation and reduced risk of PTB upon additional adjustment for caesarean section. Adding HMW‐adiponectin to the multivariable models attenuated most associations, and HMW‐adiponectin was a significant predictor in the models.

Conclusion

Our findings suggest that lower maternal 25(OH)D concentrations in overweight/obese pregnant women at high‐risk of GDM are associated with increased cardiometabolic risks during pregnancy and adverse pregnancy outcomes, and that these associations may be mediated by HMW‐adiponectin.

     

Fatty acid accumulation in the different fractions of the developing corn kernel

In the food industry, the use of the oil is determined by the composition of fatty acids, and this is highly dependent on its natural origin. The fatty acid composition of whole corn kernel was determined in three varieties of corn (Astro, GH2547, and Local). Linoleic acid was the predominant fatty acid in the oil of Astro and Local at all collection dates, whereas it was the major fatty acid in the oil of GH2547 only between 40 and 60 days after pollination (DAP). The fatty acid accumulation in the endosperm, pericarp and germ fractions of the corn kernel during maturation was determined. The accumulation pattern of oil content was different in these three kernel fractions. The highest levels of oil content in the endosperm (2.2%), germ (34.3%) and pericarp (10.8%) fractions were detected at 20, 40 and 30 (DAP), respectively. The fatty acid accumulation patterns were different amongst the analysed kernel parts, indicating a numerous differences between the three corn kernel parts. Throughout the sampling periods, the endosperm fraction was distinguished by the highest and the lowest levels of oleic and linoleic acids, respectively. At all stages of kernel development, the pericarp fraction had the highest levels of total polyunsaturated fatty acids, which has numerous healthy applications. These results may be useful in the understanding of the potential source of the beneficial unsaturated fatty acids amongst the different fractions of the corn kernel during maturation.     

VARIETAL AROMA COMPOUNDS OF VITIS VINIFERA CV. KHAMRI GROWN IN TUNISIA

ABSTRACT

The aroma composition of the grape juice of Khamri, a native variety of Vitis vinifera grown in Tunisia, was investigated for the first time. A total of 27 free and 20 glycosidically bound compounds were identified by gas chromatography‐mass spectrometry. According to the obtained results, the aroma compounds were C6 alcohols, benzene compounds, terpenes, acids and norisoprenoids. On the basis of gas chromatography‐olfactometry, these compounds were grouped, according to volatiles exhibiting the identical odor quality, into 10 groups of the same character (aromatic series) as a way of establishing an aroma profile for the studied variety. The high glycosidically bound norisoprenoid concentrations and the absence of the bound form of the acids were a positive factor for the Khamri variety potential aroma.

PRACTICAL APPLICATIONS

This article aimed on the identification of the unknown Tunisian grapevine varieties that are very well adapted to the arid conditions and that could have a good quality. The discovery of unknown autochthonous grapevine varieties with good aroma and pomological characteristics could be of great importance for the agriculture sector all over the world especially the arid regions.

     

HEAT SHOCK REDUCES BOTH CHILLING INJURY AND THE OVERPRODUCTION OF REACTIVE OXYGEN SPECIES IN YELLOW PITAYA (HYLOCEREUS MEGALANTHUS) FRUITS

ABSTRACT

Yellow pitaya fruits were heat‐shocked (25C/24 h), stored at 2C for 14 days and then held for 13 days at 18C. Chilling injury (CI), respiration rate, hydrogen peroxide (H₂O₂), superoxide anion radical (O₂•^‐) and lipid peroxidation product (LPP) levels were measured. Pitting and browning were detected in the control fruit when moving from 2 to 18C. Minor CI symptoms were found in the treated fruit. There was a rapid increase in the levels of H₂O₂, O₂•^‐ and LPP in the control fruits when moved to 18C. At the end of the storage, the levels of these compounds were 4.5‐, 4.9‐ and 6.2‐fold higher, respectively, in the control than in the treated fruit. The results suggest that the reactive oxygen species levels in the heat‐shocked fruit were adequate for normal ripening, while the levels in the control group were excessively high, inducing CI symptoms.

PRACTICAL APPLICATIONS

Refrigeration is a technique that can be used to extend shelf life of yellow pitaya fruit. Nevertheless, these fruits are susceptible to chilling injury. This research was developed to study the effect of heat shock treatment on the preservation of whole yellow pitaya fruit during refrigeration. Preheating fruit at 25C for 24 h before storage at 2C for 14 days prevented chilling injury during shelf life at 18C. Thus, the combination of heat shock and refrigeration delays the senescence of yellow pitaya fruit and therefore improves its shelf life. Furthermore, this treatment could be useful during quarantine treatments of fruit fly‐infested fruit.