Cherimoya Fruit Research Articles

Potent cryoprotective activity of cold and CO 2-regulated cherimoya ( Annona cherimola) endochitinase

A cryoprotective chitinase (BChi14) was isolated and purified from the mesocarp of CO 2-treated cherimoya fruit ( Annona cherimola Mill.) stored at chilling temperature by anion exchange and chromatofocusing chromatography. This hydrolase was characterized as an endochitinase with a M r of 14.31 kDa and a pI of 8.26, belonging to the family 19 of glycosyl hydrolases (GH19). While it was stable over a wide pH range and active in a broad acidic pH range, it had an optimum pH of 7.0. Its optimum temperature was low, 35 °C, and it retained about 30% of its maximum activity at 5 °C. Moreover, BChi14 was relatively heat unstable and its activity was progressively lost at temperatures above 50 °C. Kinetic studies revealed many similarities with other plant endochitinases. However, BChi14 had high k cat (6.93 s −1) value for the fluorogenic substrate 4-MU-(GlcNAc) 3, reflecting its great catalytic efficiency. Moreover, a thermodynamic characterization revealed that the purified enzyme displayed a high k cat at 37 and 5 °C, and a low E a (11.32 kJ mol −1). In vitro functional studies indicated that BChi14 had no effect on the inhibition of Botrytis cinerea hyphal growth and no antifreeze activity, as shown by the thermal hysteresis analysis using differential scanning calorimetry. However, the purified endochitinase showed very strong cryoprotective activity against freeze–thaw inactivation of lactate dehydrogenase. The PD 50 was 12.5 times higher than that of the cryoprotective protein BSA, and 2 or 3 orders of magnitude greater than sucrose, comparable with that of most cryoactive plant dehydrins. These results, together with the consolidated microstructure and the integrity of CO 2-treated mesocarp tissue, indicate that BChi14 is functionally implicated in the mechanisms underlying chilling tolerance activated by high CO 2 concentrations.

Abstract 1900: Antioxidant studies on the Peruvian cherimoya fruit give an insight into the healthy lifestyle of the Incas

Abstract Annona cherimola, known as “cherimoya” was grown as an essential crop in the Incan empire, and was believed to prevent disease. Indigenous to Peru and Ecuador, this “pearl of the Andes” is consumed mainly for its exceptional taste. American writer Mark Twain called the cherimoya “the most delicious fruit known to men.” Recent interest in this fruit stems from its high concentration of acetogenins, which are bioactive polyketides. Recent research has accredited beneficial effects to acetogenins, including the exhibition of cytotoxic and anti-tumorous activity, particularly in mammary, pancreatic and colon cancer cells (Cheng et. al 1998). This project explores the health benefits of cherimoya consumption by examining the antioxidant effect of its components, including: skin, flesh and juice. These components were analyzed for antioxidant concentrations using the Oxygen Radical Absorbance Capacity (ORAC) assay. A cellular model was also established that evaluated the antioxidant capacity of cherimoya components in the presence of Raji cells, a Burkitt lymphoma cell line, and HT-29 cells, a colon cancer cell line. After incubation with the cherimoya components, cell lysate samples were assessed for antioxidant capacity using the ORAC assay. Results for Raji cell lysate exposed to media, juice, skin and flesh were as follows: 886 Trolox Equivalents per Liter (TE/L), 1238 TE/L, 1018 TE/L, and 1045 TE/L respectively. Results for HT-29 cell lysate exposed to media, juice, skin and flesh were: 294 TE/L, 924 TE/L, 505 TE/L and 627 TE/L respectively. These data shows that cells treated with cherimoya juice exhibited a higher antioxidant uptake. An alternate cellular model was established in which Raji cells and HT-29 cells were pre-exposed to oxidant AAPH, 2,2’-azobis-(2-amidinopropane) dihydrochloride, and then treated with cherimoya juice, skin and flesh. Results for Raji cells exposed to AAPH and then treated with media, juice, skin and flesh were as follows: 1054 TE/L, 1363 TE/L, 1183 TE/L, and 1254 TE/L respectively. Results for HT-29 cells exposed to AAPH and then treated with media, juice, skin and flesh were: 1075 TE/L, 1528 TE/L, 1350 TE/L and 1374 TE/L respectively. These data indicated that when cells were pre-exposed to an oxidant, thus simulating cells under oxidative stress, antioxidant cell uptake increased for both cell lines. These results suggest that cells can sense oxidative stress in their environment and can increase their ability to uptake available antioxidants. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1900.

INDUCTION OF SMALL HEAT-SHOCK PROTEINS IN MESOCARP OF CHERIMOYA FRUIT (ANNONA CHERIMOLAMILL.) PRODUCES CHILLING TOLERANCE

Cherimoya is a major crop in the subtropical areas of the Spanish coast. The fruit are perishable because of their rapid climacteric ripening. Storage between 10 and 12C produces some extension of the shelf life of the fruit as a small delay in senescence is produced. A lower storage temperature produces chilling injury. The aim of this work is to find a way to make the fruit more resistant to low temperatures. In several plant species the synthesis of small molecular size heat-shock proteins (sHSPs) prevents and/or repairs stress induced damage; therefore, we investigated the induction of sHSPs in the mesocarp of cherimoya fruit. Heating the fruit at 55C during 5 h produces alleviation of the chilling-injury symptoms when the fruit are stored at 4C. The thermal stress induces proteins recognized by antibodies against sHSPs of different classes from other plant species. This induction is proportional to the temperature in the experimental range of 46–50C. PRACTICAL APPLICATIONS Refrigeration is the only described way to extent shelf life of cherimoya as senescence is delayed by the decreasing temperature. This is true until chilling injury appears. Senescence of this fruit occurs in 4–5 days when stored at 20C, which is a regular temperature in the production area. Storage at 10–12C allows commercialization during one additional week. Different attempts have been made to extend the period of conservation by using controlled atmosphere and lower temperatures. The problem is that cherimoya fruit are very susceptible to chilling injury. If a short heating treatment induces small molecular size heat-shock proteins (sHSPs), which would further protect the fruit from chilling injury, this would probably allow a lower temperature for transportation and conservation, thus increasing the period for commercialization. Exportation could be done in a safer way.

Residual effect of atomised water vapour treatment on carbohydrate metabolism during ripening of cv “Fino de Jete” cherimoya fruit

Atomised hot water vapour at between 46 and 54 °C for 60 min was tested as a method of delaying ripening and extending shelf life in cv “Fino de Jete” cherimoya fruit (Annona cherimola Mill.). Heat treatment at 46 °C stimulated the respiration rate and starch degradation, induced ethylene production, increased the accumulation of soluble sugars and α-amylase activity, and moved the onset of ethylene production (OEP) forward. Treatment at 50 °C, and especially at 52 °C, delayed the climacteric peak and the OEP, decreased sugar and organic acid accumulation, and reduced α-amylase and invertase activity. The results obtained indicate that temperatures higher than 48 °C slowed physiological processes and carbohydrate metabolism and extend the shelf life of the cherimoya fruits, while temperatures higher than 52 °C blocked ripening irreversibly.

1-MCP delayed softening and affected expression of XET and EXP genes in harvested cherimoya fruit

Cherimoya, a typical climacteric fruit, is very susceptible to postharvest losses, due to rapid softening. It has been reported that xyloglucan endotransglycosylases (XET) and expansins (EXP) contribute to fruit softening while 1-methylcyclopropene (1-MCP) is used to delay softening in many fruit. However, the effects of 1-MCP on cherimoya fruit softening and in relation to the expression of XET and EXP genes remain unclear. In this study, three different full length XET cDNAs, termed AcXET1, AcXET2 and AcXET3, were isolated and characterized. Delay in cherimoya fruit softening by 1-MCP in relation to the expression of XET and EXP genes was investigated. Cherimoya fruit stored at 20 °C softened rapidly within 5 d and displayed a typical climacteric pattern of ethylene production. Application of 1-MCP greatly delayed and inhibited ethylene production and softening of fruit during storage at 20 °C. Northern blot analysis showed that three AcXETs or AcEXPs exhibited different expression patterns during fruit softening while mRNAs of AcXET2, AcEXP1 and AcEXP3 significantly accumulated on day 3 and mRNAs of AcXET1 or AcEXP2 accumulated on day 5 or day 6. 1-MCP treatment not only delayed the accumulation of AcXET1, AcEXP1 and AcEXP3 for 1, 3 and 2 d, respectively, but also reduced the mRNA levels of AcXET1, AcXET2, AcXET3, AcEXP1, AcEXP2 and AcEXP3. These data suggest that differential expression of AcXETs and AcEXPs is associated with fruit softening of cherimoya and application of 1-MCP retarded or suppressed the expression of AcXETs or AcEXPs, which may be attributed at least or partially to 1-MCP delayed fruit softening.

Expansin gene expression in cherimoya fruit is correlated with flesh firmness during fruit ripening and softening

SummaryExpansins are proteins that have been shown to contribute to fruit softening. However, whether expansins are involved in the loss of flesh firmness in harvested cherimoya fruit has not yet been confirmed. In this study, three different full-length expansin gene (AcExp1, AcExp2, and AcExp3) cDNAs from ripe cherimoya fruit were isolated and characterised, and their patterns of mRNA expression were investigated in relation to flesh firmness in fruit stored at different temperatures (10°C, 15°C, or 20°C) and in fruit stored at 20°C and pretreated with propylene. The results showed that flesh firmness began to decline on day-2 after storage and declined rapidly by day-4. Meanwhile, ethylene production increased significantly by day-4 after storage at 20°C. Flesh firmness declined slowly and fruit exhibited a low level of ethylene production throughout storage at 10°C. RNA hybridisation revealed that AcExp1 mRNA was detectable throughout 8 d of storage at 10°C, 15°C, or 20°C, and that AcExp2 mRNA was detectable only after the decline in flesh firmness in fruit stored at 15°C or 20°C. Moreover, the accumulation of AcExp3 mRNA coincided with the decline in flesh firmness in fruit stored at 15°C or 20°C. Propylene treatment increased ethylene production, accelerated the decline in flesh firmness in fruit stored at 20°C, and increased the accumulation of AcExp2 and AcExp3 mRNAs. These findings therefore show that AcExp3, together with AcExp2, may be involved in cherimoya fruit softening.

MARKETING OF CHERIMOYA IN THE ANDES FOR THE BENEFIT OF THE RURAL POOR AND AS A TOOL FOR AGROBIODIVERSITY CONSERVATION

ISHS International Symposium on Underutilized Plants for Food Security, Nutrition, Income and Sustainable Development MARKETING OF CHERIMOYA IN THE ANDES FOR THE BENEFIT OF THE RURAL POOR AND AS A TOOL FOR AGROBIODIVERSITY CONSERVATION

Effect of Harvest Time and L-Cysteine as an Antioxidant on Flesh Browning of Fresh-Cut Cherimoya (Annona cherimola Mill.)

A B S T R A C T Browning development is the most important factor limiting the quality of fresh-cut cherimoya (Annona cherimola Mill.). However, there is little information available about its causes and methods of control. The effectiveness of L-cysteine (0.125, 0.25 and 0.5%) in fresh-cut cherimoya harvested on two occasions (October and November) and stored for 6 and 12 days at 0 °C was studied. In order to understand the biological basis of browning, polyphenol oxidase (PPO) enzyme activity and total phenolic content in fresh-cut pieces were measured. Quality measurements and sensory analysis indicated that 0.5% L-cysteine was somewhat effective in reducing browning development, without affecting other quality attributes. In terms of physiological parameters, PPO activity did not show differences between mature (at harvest) and ripe fruit (at processing) in both harvest times, but cherimoya fruits picked in November presented lower PPO activity than fruit from October. In general, PPO activity and total phenolic content of L-cysteine treated fruits did not show consistent differences with untreated fruit at 6 or 12 days at 0 °C. PPO activity analyses demonstrated that PPO activity was higher in the outer part of cherimoya flesh compared to the middle or inner sector. These results would support the possibility of using L-cysteine as a postharvest treatment to reduce browning development in fresh-cut cherimoya.

Development of a New Technique to Produce Winter Cherimoyas

This paper describes a novel technique to produce cherimoya (Annona cherimola) fruit during the winter season. In a controlled experiment the trees were encouraged to flower out of season by pruning them back severely in January, followed by tipping the newly emerged shoots together with the removal of apical leaves on either 1 or 15 June. Both dates were highly successful because all tipped shoots produce a second bloom in July. On average, four flowers per shoot were produced in the new growth in response to defoliation treatments. The second blooming lasted no more than 2 weeks. Late-forming flowers were hand pollinated and gave rise to fruit of high quality about 50 d later than an ordinary crop. A yield of 13 t·ha−1 was produced, with no significant differences between treatments. Postponing hand defoliation by 15 days delayed the harvest period 15 to 20 days, but no other effects on fruit set and quality were noted. Fruit harvested in December and January did not show chilling injury and reached full flavor. Number of seed per fruit, and consequently fruit size, was often increased in out-of-season cherimoyas. Late fruit suffered less preharvest drop than an ordinary crop. This work shows the possibility of producing high-quality cherimoyas during winter when the cherimoya fruit is in great demand.

Effects of microwave treatment on storability of postharvest cherimoya(Annona squamosa) fruits

Effects of microwave treatment on storability of postharvest cherimoya(Annona squamosa) fruits

Browning inAnnona cherimolaFruit: Role of Polyphenol Oxidase and Characterization of a Coding Sequence of the Enzyme

Cherimoya (Annona cherimola Mill.) fruit is an attractive candidate for food processing applications as fresh cut. However, along with its desirable delicate taste, cherimoya shows a marked susceptibility to browning. This condition is mainly attributed to polyphenol oxidase activity (PPO). A general lack of knowledge regarding PPO and its role in the oxidative loss of quality in processed cherimoya fruit requires a better understanding of the mechanisms involved. The work carried out included the cloning of a full-length cDNA, an analysis of its properties in the deduced amino sequence, and linkage of its mRNA levels with enzyme activity in mature and ripe fruits after wounding. The results showed one gene different at the nucleotide level when compared with previously reported genes, but a well-conserved protein, either in functional and in structural terms. Cherimoya PPO gene (Ac-ppo, GenBank DQ990911) showed to be present apparently in one copy of the genome, and its transcripts could be significantly detected in leaves and less abundantly in flowers and fruits. Analysis of wounded matured and ripened fruits revealed an inductive behavior for mRNA levels in the flesh of mature cherimoya after 16 h. Although the highest enzymatic activity was observed on rind, a consistent PPO activity was detected on flesh samples. A lack of correlation between PPO mRNA level and PPO activity was observed, especially in flesh tissue. This is probably due to the presence of monophenolic substrates inducing a lag period, enzyme inhibitors and/or diphenolic substrates causing suicide inactivation, and proenzyme or latent isoforms of PPO. To our knowledge this is the first report of a complete PPO sequence in cherimoya. Furthermore, the gene is highly divergent from known nucleotide sequences but shows a well conserved protein in terms of its function, deduced structure, and physiological role.

Gelatinization and retrogradation of native starch from cherimoya fruit during ripening, using differential scanning calorimetry

The aim of this work was to determine the physicochemical characteristics of non-conventional starch from cherimoya fruit in order to suggest possible applications of these polymers in various food systems. The influence of the stage of ripening on thermal behaviour of cherimoya fruit starch was also analysed. Starch was visualized by cryo-SEM, and gelatinization and retrogradation properties were studied by differential scanning calorimetry (DSC). DSC was also used for accurate determination of the starch content of cherimoya dry matter. The calorimetric profile for cherimoya fruit starch showed a peak temperature (gelatinization) over a range from 63.7 to 65.2 °C and enthalpy values between 14.8 and 15.9 J g −1 during ripening. Neither temperatures nor melting enthalpy of recrystallized amylopectin differed over the ripening period. The recrystallization rate, as measured by changes in melting enthalpy with time according to the Avrami model, showed a very slight retrograde tendency. It is suggested that these characteristics could be useful in products where good quality and long shelf-life are required.

Changes in water status of cherimoya fruit during ripening

Changes in the state of water of cherimoya ( Annona cherimola Mill.) fruit during ripening were monitored using differential scanning calorimetry (DSC) and magnetic resonance imaging (MRI) techniques. The stage of ripening was determined by analyzing the changes in titratable acidity, firmness and total soluble solids contents. Furthermore, quantitative measurements of solutes such as proline, sucrose, glucose and fructose were also studied. The significant increase in the transverse relaxation time ( T 2) values and the loss of flesh firmness during the initial stage of ripening are consistent with the sustained drop in the unfreezable water weight fraction according to the DSC data. The ripe stage of the fruit was marked by minimum longitudinal relaxation time ( T 1) values and a rapid upsurge in the unfreezable water weight fraction, greatly influenced by the osmotic adjustments prompted by the significant accumulation of soluble sugars, proline and carboxylates. Changes in structure and solute concentration associated with ripening can be analyzed simultaneously, determining fruit water status by DSC.

Fatty acid composition of phospholipids in mesocarp of cherimoya fruit during ripening

Mature-green cherimoya ( Annona cherimola Mill.) fruits were stored for 6 days at 22 °C. The analysis of the lipid classes in mesocarp tissue of mature-green and senescing fruits showed that the senescence of cherimoya was characterized by a decrease of phospholipid content. The fatty acid composition of the mesocarp phospholipids was studied in fruits at harvest, on day 3 and 6. Twenty different fatty acids were identified. The C16:0, C18:0, C18:1, C18:2 n−6 and C18:3 n−3 fatty acids clearly were the most abundant fatty acids and the C18 family comprised more than 50% of total fatty acids content. Major variation in the relative composition of mesocarp phospholipid fatty acids were observed at the pre-climacteric stage. These changes did not modify the unsaturation index of the membrane but increased the unsaturation level for C18 fatty acids class. In senescing fruit, a decrease in all unsaturation indexes calculated was found. The results indicated that the modification of the relative quantity of specific polyunsaturated fatty acids in phospholipids was more relevant than the total content of fatty acids for the adaptation of mesocarp membranes to ripening and senescence processes in cherimoya fruit.

Malate Metabolism and Adaptation to Chilling Temperature Storage by Pretreatment with High CO2 Levels in Annona cherimola Fruit

In this study we focused on the effect of a pretreatment with high (20%) CO2 levels on malic acid metabolism in cherimoya (Annona cherimola Mill) fruit stored at chilling temperature. We analyzed the activity of phosphoenolpyruvate carboxylase (PEPC), malate dehydrogenase (MDH), and the NADP-malic enzyme (NADP-ME), involved in the carboxylation/decarboxylation of malate. Our results show that CO2 treatment, which improves tolerance to prolonged storage at chilling temperature, was closely linked to considerably greater NADP-ME activity. These results, combined with lower PEPC activity, may explain the significantly lower amount of malic acid and titratable acidity quantified in CO2-treated fruit. Moreover, the high cytoplasmic MDH enzyme activity and the strong stimulation of NADP-ME activity exhibited by CO2-treated fruit could be contributing factors in the maintenance of fruit energy metabolism, pH stability, and the promotion of synthesis of defense compounds that prevent or repair damage caused by chilling temperature.

Relationship between the levels of ammonia and co-ordination of phenylalanine ammonia-lyase and phosphoenolpyruvate carboxylase in Annona cherimola stored under different conditions

Abstract The levels of ammonia in cherimoya ( Annona cherimola , Mill) fruit changed in response to different storage conditions. The highest amount of ammonia was observed in fruit stored at a chilling temperature, and the lowest ammonia level was found in CO 2 -treated fruit at ambient temperature. These fruit presented the highest amount of nitrogen incorporated in polyamines, mainly in spermidine and spermine. Moreover, the fact that the trend in polyamines and ammonia content reverted when treated fruit were transferred to air would appear to confirm preferential reassimilation of ammonia under high CO 2 treatment. The increase in phenylalanine ammonia-lyase (PAL) activity observed in ripening fruit at ambient temperature was substantially reduced in fruit stored at a chilling temperature. Our results suggest that PAL activity increases in fruit with a high demand of ammonia for further assimilation processes, and that this activity decreases in fruit where ammonia reassimilation does not take place. Additionally, in the case of CO 2 -treated fruit, ammonia availability is apparently promoted by the deamination of amino acids, which is reflected in a significant decrease in free amino acid content without a concomitant rise in total protein levels. We observed that the patterns of change in phospho enol pyruvate carboxylase (PEPC) and PAL activities were opposite. Moreover, coordination between these enzymes was related to the metabolic endogenous levels of ammonia. The role of ammonia levels as a significant metabolic signal for controlling carbon and nitrogen metabolism is discussed.

Effects of storage temperature and wax coating on ethylene production, respiration and shelf-life in cherimoya fruit.

Effects of storage temperature and wax coating on ethylene production, respiration and shelf-life in cherimoya fruit.

Phospho enolpyruvate carboxylase from cherimoya fruit: properties, kinetics and effects of high CO 2

Phospho enolpyruvate carboxylase (PEPC, EC 4.1.1.31) regulatory properties were studied in non-photosynthetic (mesocarp) and photosynthetic (peel) tissues from cherimoya ( Annona cherimola Mill.) fruit stored in air, in order to gain a better understanding of in vivo enzyme regulation. Analyses were also performed with fruit treated with 20% CO 2–20% O 2 to define the role of PEPC as part of an adaptive mechanism to high external carbon dioxide levels. The results revealed that the special kinetic characteristics of the enzyme from mesocarp—high V max and low sensibility to l-malate inhibition - are related to the active acid metabolism of these fruits and point to a high rate of reassimilation of respired CO 2 into keto-acids. With respect to fruit stored in air, PEPC in crude extracts from CO 2-treated cherimoyas gave a similar V max (1.12±0.03 μkat·mg −1 protein), a lower apparent K m (68±9 μM for PEP) and a higher I 50 of l-malate (5.95±0.3 mM). These kinetic values showed the increase in the affinity of this enzyme toward one of its substrate, PEP, by elevated external CO 2 concentrations. The lower K m value and lower sensitivity to l-malate are consistent with higher in vivo carboxylation reaction efficiency in CO 2-treated cherimoyas, while pointing to an additional enzyme regulation system via CO 2.

Effect of high carbon dioxide concentration on PAL activity and phenolic contents in ripening cherimoya fruit

Abstract Cherimoya fruit ( Annona cherimola , Mill.) were kept at 20°C in air or in 20% CO 2 for 3 days and then transferred to air, to study the effect of a high CO 2 treatment on phenolic metabolism and ripening-related changes. Total polyphenol levels remained constant while a rapid decline in lignin content was observed in cherimoyas stored in air. However, a sharp increase in PAL activity up to the second day at 20°C was observed. The maximum ethylene production was observed 2 days later. At the end of the CO 2 treatment, ethylene production was inhibited and PAL activity was similar to that found in air-treated fruit. These data suggest that the increase in PAL activity at 20°C was not affected by high CO 2 and does not relate to ethylene. The CO 2 treatment inhibited flesh softening and maintained lignin at levels found in freshly harvested fruit. Exposure to 20% CO 2 also improved internal colour and increased the non-tannin polyphenol fraction, but prevented the decline in the tannin fraction otherwise observed upon ripening in air. We concluded that high CO 2 treatment at 20°C did not enhance PAL activity and lignin deposition although treated fruits retained more lignin after transfer to air. The possible involvement of PAL activity in the supply of important metabolic compounds for early events of ripening will be discussed.

Influence of harvest date within the season and cold storage on cherimoya fruit ripening.

Cherimoya ripening with and without prior storage at 8 degrees C was studied in fruit harvested on early- (EH), mid- (MH), and late-season (LH) dates. Most of the differences in the ripening behavior were observed between EH cherimoyas and fruit from the other two harvest dates. During ripening of nonstored fruit, the increases in ethylene production and respiration rates and in soluble sugars and organic acids contents were faster in EH than in the other fruits (which ripened 1 day later). These differences could be due to variations in the physiological stage at harvest as a result of the different heat units (degree/month) accumulated in the last month of fruit development. During ripening of cold-stored fruit the differences in the time to the onset of the increase in ethylene production and in the accumulation of malic and citric acid were minimized, especially after longer storage times, and the relationship of harvest date with the increases in respiration rate was lost. Glucose and fructose accumulation was reduced by prior cold storage, especially after longer storage duration and in MH and LH fruit, but sucrose hydrolysis was almost complete, as in nonstored fruit. It is suggested that glucose and fructose accumulation is more sensitive to low temperature than sucrose metabolism and that this differential sensitivity is more marked in MH and LH cherimoyas. The time to ripen was inversely related to prior cold storage duration and was dependent on harvest date: the later the harvest date, the longer storage time it took to shorten subsequent ripening.