Incidence Of Internal Browning Research Articles

Transcriptome and metabolome analysis of preharvest internal browning in Nane plum fruit caused by high temperatures

The preharvest internal browning of Nane plum fruit, with no visible effects on the appearance of the fruit, has become a serious problem in recent years in its production area in Guangdong Province, China. This study investigated the effects of environmental factors, including temperature, on Nane plum internal browning. Plum orchards at different elevations with different incidences of internal browning were selected. Using fruits with different internal browning incidence levels, the internal browning mechanism was analyzed with transcriptome and metabolome analyses. The results revealed decreased internal browning at high altitudes. Shading treatment significantly reduced internal browning, whereas bagging and insect-proof net-covering treatments significantly increased internal browning. Because bagging and net coverings increase the local ambient temperature, the findings suggest that high temperature is an important factor influencing the internal browning of Nane plum. The metabolome experiments showed that with increased internal browning, the levels of phenolic hydroxyls such as catechol increased, with simultaneous increases in hydrogen peroxide content and oxidase activity. It can be speculated that the oxidation of phenolic hydroxyl substances is the main cause of the preharvest browning of Nane plum. Transcriptome analysis revealed the increased expression of calcium signaling-related and downstream effector genes and indicated an important role of calcium in internal browning, possibly due to its increased content in the fruit. Further, with increasingly serious internal browning, genes related to photosynthesis were down-regulated, while genes related to senescence were up-regulated, thus suggesting the up-regulation of the process of cell senescence during internal browning. In conclusion, heat stress should be eliminated to reduce preharvest internal browning in Nane plum.

Postharvest treatments influenced the incidence of internal browning, phenol, ABA, AND GA3 contents of two pineapple clones

Phenol is an internal browning (IB) enzymatic reaction substrate and endogenous abscisic acid (ABA) used to suppress IB incidence in the Comte de Paris cultivar (Queen type). There is no information on the correlation between pineapple IB to endogenous total phenol content (TPC), ABA, and gibberellic acid 3 (GA3) after postharvest applications of decrowning. Therefore, this research aimed to analyze the relationship of IB incidence to total TPC, ABA, and GA3 after postharvest treatments of decrowning and coating in GP3 and MD2 pineapple clones. The structure was based on a completely randomized design with 3 factors, namely clone (GP3 and MD2), decrowning (crown and crownless), and coating [50 mg L-1 ABA, 1% chitosan, ABA+Chitosan mixture, and control (H2O)]. The results showed that the MD2 had a lower IB incidence and higher TPC than the GP3 stored at 7°C for 37 days. The increased TPC was positively correlated with IB incidence. TPC was also negatively correlated with ABA but positively with endogenous GA3 2 weeks earlier. Coating with 50 mg L-1 ABA and 1% chitosan on MD2 decreased IB incidence. Pineapple crown pruning decreased ABA and increased TPC, GA3, and IB incidence.

Effect of storage temperature transfer on the internal browning and other fruit qualities of GP3 and MD2 pineapple clones after postharvest applications of ABA, chitosan and decrowning

Changes in pineapple storage temperature accelerate the increase in internal browning (IB) incidence. This study aims for postharvest applications with changes in storage temperature affecting IB incidence and severity. This research was conducted on ‘GP3’ and ‘MD2’ pineapple clones when they were ripe for export. The experimental were a completely randomized design of storage temperatures (T1: at 7°C for 30 days and T2: at 7°C for 28 days followed by 16°C for 2 days), clones (‘GP3’ and ‘MD2’), decrownings (crown and crownless), and coatings [chitosan 1%, ABA 50mg/L, ABA+chitosan mixture, and control (H2O)]. The results showed that T2 had a significant effect on the increase IB incidence in ‘MD2’ and IB severity in ‘GP3’ compared to T1. Ascorbate acid decreased in ‘MD2’ stored at T2, but had no effect on ‘GP3’. Soluble solid content (SSC) of ‘MD2’ was higher than ‘GP3’. Titratable acidity (TA), SSC/TA ratio, and mold severity were not significantly affected by treatments. The T2 had a significant effect on fruit temperature (FT), with an increase of 2.77-2.88ºC. An increase in FT was positively correlated with maturity, fruit weight loss, and skin dehydration. During the 28 to 30 days of storage, the T2 treatment increased in ripeness by 81.25%.

Impact of exogenous pre and postharvest salicylic acid applications on MD2 pineapple quality

Salicylic acid (SA) is a natural plant compound that has been proven to enhance the quality of fruits; therefore, its impact on pineapple should be further studied, especially in the most marketable hybrids. This study aimed to evaluate the effect of SA treatments on MD2 pineapple quality. The experiment consisted of two parts with applications pre and postharvest following the next treatments, control: No use of SA, and 5, 7 and 9 mM of SA. The total soluble solids, total acidity, ascorbic acid content, respiration rate, together with the severity and incidence of internal browning and flesh translucency were determined, after 40 days of cold storage. The treatment using 9 mM of SA in pre and postharvest delivered the best results, having the most elevated ascorbic acid (526.75 mg kg-1) and total acidity (0.8%), the lowest severity and incidence outcomes of internal browning and flesh translucency (0% in both cases), with the most reduced respiration rate values during postharvest. In conclusion, SA treatments with concentrations of 9 mM applied in pre and postharvest on MD2 pineapple can improve its quality after 40 days of cold storage.

The Potential Roles of the N and P Supplies on the Internal Browning Incidence in Sweet Cherries in the Southern Chile

Southern Chile has experienced a strong increase in sweet cherry production in recent years. However, there are climatic gaps that negatively reduce the fruit quality and yield of exportable fruit, such as the high incidence of rains during flowering and pre-harvest. The use of roof covers has become an agronomic solution that offers protection from weather events, such as rain, which will significantly increase the exportable fruit. However, the use of plastic covers can cause negative impacts on the fruit, such as a loss of firmness and acidity. Currently, the incidence of internal (pulp) browning has reduced the quality of cherries produced in Southern Chile, although research on this subject is largely under explored. Some studies reported that a high content of antioxidants in the fruit, both phenolic and non-phenolic (e.g., ascorbic acid), could reduce the incidence of the physiological disorder of browning. The soils of Southern Chile are characterized by the high content of organic matter, which implies high levels of available nitrogen (N) and a high phosphorus (P) content. Some studies, however, have shown that fertilization with N and P would significantly improve the postharvest quality, shelf life, and the accumulation of antioxidant compounds in fruits, even better than other strategies, including selenium and chitosan applications. However, there needs to be more detailed information on this aspect of the sweet cherry fruit production. The quality attributes and postharvest life of cherries are closely associated with the antioxidant levels of fruits, which could be related to either the soil acidity level of the Chilean Andisols or the levels of P and N in soil or plant tissues. Therefore, the objective of this review was to discuss the role of the N and P supply on the internal browning incidence in sweet cherries and relate it to what is known in other fruits.

Insight into the physiological and molecular mechanisms of hot air treatment which reduce internal browning in winter-harvested pineapples

Internal browning (IB) in pineapple is a serious physiological disorder that occurs during storage which results in serious quality deterioration and losses. This study investigated the inhibitory effects of postharvest hot air (HA) treatment on pineapple IB occurrence during storage. Winter-grown ‘Comte de Paris’ pineapples were treated with HA (38 °C and 80–90% RH for 3 d) before storage at 25 °C. The results showed that HA treatment reduced the incidence of IB where HA treatment also resulted in lower malondialdehyde (MDA) content and superoxide anion (O2-.) production rates, suggesting that oxidative stresses are involved in the development of IB in pineapple. Further metabolomic and related enzyme activity results showed that the HA treatment inhibited the accumulation of p-coumaric acid which resulted from the increase of tyrosine ammonia-lyase, cinnamate-4-hydroxylase and p-coumarate: coenzyme A ligase enzyme activities. Lower levels of 4-methoxy-4-vinylphenol, L-tyrosine, and ascorbic acid and higher levels of polyphenol oxidase were also observed in control fruit with IB symptoms. Transcriptome analysis revealed that the pathways of alpha-linolenic acid metabolism, phenylpropanoid biosynthesis, MAPK signal pathway and the protein processing in endoplasmic reticulum were significantly affected by HA treatment. Identification of the IB-related genes family in these pathways showed that HA treatment inhibited the expressions of phospholipase D (PLD), lipoxygenase (LOX), dioxygenase (DOX), resiratory burst oxidase homologue (RBOH), phenylalanine/tyrosine ammonia-lyase (PAL/TAL), cinnamate-4-hydroxylase (C4H), p-coumarate: coenzyme A ligase (4CL) and polyphenol oxidase (PPO) and up-regulated the expressions of heat shock factors (HSF), heat shock proteins (HSPs), phospholipase A2 (PLA2) and ascorbate peroxidase (APX), therefore alleviating IB in winter-harvested pineapples. A conceptual model elucidating the alleviation of IB by HA in pineapples was proposed.

Gas exchange model using heterogeneous diffusivity to study internal browning in ‘Conference’ pear

Internal gas gradients in pear fruit during controlled atmosphere storage depend on the effective gas diffusivity of the tissue. The diffusivity varies over the fruit organ due to the heterogeneous tissue microstructure across the fruit. This study implemented effective diffusivity maps reflecting the heterogeneous structure to predict internal gas gradients and relate the result to the occurrence of internal browning. Diffusivity maps of different pears were calculated from X-ray CT based porosity maps. Internal oxygen (O2), carbon dioxide (CO2) and respiratory quotient (RQ) levels were computed using a reaction-diffusion model incorporating the heterogeneous effective diffusivity map. Critical O2 and RQ levels for the shift from respiration to fermentation were defined based on the respiratory-fermentative energy balance of the cells. The model was indirectly validated by comparing RQ level contours with non-destructive 3D images of the internal browning of the pears after storage at 1.0 kPa and 0.5 kPa O2, combined with 0.7 kPa CO2 at 1 °C. The distribution of the internal gas concentrations and RQ was affected by the heterogeneity of the diffusivity. The results also confirmed the incidence of internal browning when the O2 and RQ were under or above critical O2 and RQ limits, respectively. The fermentation process was indicated to be dominant when the tissue’s RQ limit (RQ*) went above 2.12 (or at 0.044 kPa O2). The tissue volumes where O2 and RQ levels were critical corresponded reasonably well to browning-affected tissues of pears with different shapes. The pear with more shallow gas gradients showed less symptoms of browning.

Seasonal variation in calcium and ascorbic acid content at harvest related to internal browning in ‘Braeburn’ apple during controlled atmosphere storage

Previous studies examining the causes of internal browning (IB) and strategies to reduce its incidence in ‘Braeburn’ apple grown in Southwest Germany have shown conflicting results. However, most studies have been conducted during only one season, requiring multi-seasonal evaluations to obtain robust data and information. IB has been associated with fruit mineral content in ‘Braeburn’ apple, and in other cultivars, ascorbic acid (AsA) is linked to IB. Few studies have investigated the possible role of the balance between mineral and AsA content on fruit susceptibility to IB. The objectives of this study were to use a four-year dataset to analyse the seasonal variation of mineral and AsA content at harvest and their relation to IB incidence in ‘Braeburn’ apple grown in Southwest Germany and stored under controlled atmosphere conditions. According to our results, the average seasonal IB incidence was highly associated with AsA and calcium contents in fruit. Fruit calcium content was positively correlated with IB incidence, whereas AsA content was negatively associated with IB. Seasonal variation in the AsA/Ca ratio at harvest followed the opposite trend to IB incidence, with a higher ratio occurring in years with lower IB incidence. Principal component analysis revealed that the relative humidity (RH) during the first 42 days after bloom (42-DAB) was positively correlated with AsA content and negatively correlated with fruit calcium content and IB incidence. Our results indicate that higher AsA and lower calcium content, due to higher RH during the first 42-DAB, are important to reduce ‘Braeburn’ apples’ susceptibility to IB during controlled atmosphere storage.

Interaction of oxygen and moisture content on ‘Barton’ and ‘Jackson’ pecan storage

The effects of the nut moisture content (MC) and storage conditions on the physicochemical quality and volatile compound (VC) profile after storage of pecan nuts are still poorly understood. Therefore, the present study aimed to evaluate the effects of MC (6 and 4 %) and the interaction with atmospheric conditions (20.9 kPa) and low O2 partial pressure (2 kPa O2) on ‘Barton’ and ‘Jackson’ pecan storage. Color parameters, internal browning (IB) incidence and severity, respiration rate, acidity, peroxide value (PV), and VC profile after 8 and 12 months of storage at 20 °C were evaluated. ‘Barton’ and ‘Jackson’ pecans stored with 6 % MC + 2 kPa O2 presented the highest hue and luminosity (L) values, i.e. lighter color, after 8 and 12 months of storage. However, ‘Barton’ and ‘Jackson’ pecans stored with 6 % MC + 20.9 kPa O2 had the highest IB incidence and severity and respiration rate. After 8 months, pecans stored with 4 % MC + 20.9 kPa O2 had lower acidity and PV in both cultivars, compared with the pecans stored under 6 % MC + 20.9 kPa O2. The lower O2 in ‘Barton’ pecans stored with 6 % MC decreased PV, which was also the case for ‘Jackson’ nuts stored at 4 % MC. Regardless of the MC, pecans stored under 2 kPa O2 had the lowest hexanal and hexanol contents in both cultivars. Our findings suggest that it is necessary to choose between reducing MC or kPa O2 when aiming to maintain the quality of ‘Barton’ and ‘Jackson’ pecans stored under ambient temperature conditions (20 °C).

Ethanol vapor, initial low O 2 , and high CO 2 stresses in the storage of Laetitia Plums

The objective of this work was to evaluate the effect of treatments with ethanol vapor, and initial low O2 (ILOS) and high CO2 (IHCO2S) stresses on the ripening and maintenance of the quality of Laetitia plums, especially regarding internal browning (IB). The treatments evaluated were control, ethanol vapor (0.5 and 1.5%), ILOS (1.5 kPa), and IHCO2S (15 kPa). Respiratory and ethylene production rates, flesh firmness, titratable acidity, soluble solids, peel color, and incidence and severity of IB were evaluated after 20 (20CS + 4SL) and 30 (30CS + 4SL) days of cold storage [0.5 ± 0.1°C and relative humidity (RH) of 96 ± 2%] plus 4 days of shelf life under room condition (23 ± 5°C and RH of 60 ± 5%). Ethanol vapor treatments (0.5 and 1.5%) and ILOS (1.5 kPa) delayed the ripening of “Laetitia” plums. These treatments prevented IB for up to 20CS + 4SL and reduced the incidence and severity of this disorder for up to 30CS + 4SL. Practical applications This study analyzes a method of treatment with ethanol vapor and low initial O2 (ILOS) and high CO2 (IHCO2S) stresses as a way to preserve the quality of “Laetitia” plums along with refrigeration. It is a good method to reduce the incidence of internal darkening of this fruit during cold storage. Also, it provides guidelines for the application of a modified atmosphere along with refrigeration for better conversation but “Laetitia” plums.

Pecan storage: Effects of 1-MCP on the overall quality and volatile compounds profile of shelled and unshelled pecans

The effects of 1-methylcyclopropene (1-MCP) treatment and shell maintenance on the physicochemical quality and volatile compounds (VC) profile of pecans after storage is still poorly understood. Therefore, the present study aimed to evaluate the effects of 1-MCP (1 ppm) application on pecans with and without shell maintenance during storage on the parameters of color, internal browning (IB) incidence and severity, respiration rate, acidity, peroxide value (PV), and VC profile after six months of storage under ambient conditions (17 ± 5.1 °C). The 1-MCP applied to the unshelled pecans maintained the luminosity and decreased IB incidence and severity. Shelled and unshelled pecans had lower acidity and PV when treated with 1-MCP. Regarding VC profile, maintaining the shell during storage decreased unwanted volatile compounds, including hexanal, octanal, and nonanal. In shelled pecans, 1-MCP treatment reduced hexanal, octanal, and nonanal content. This study is the first to demonstrate that 1-MCP application results in better maintenance of the physicochemical quality and VC profile of shelled and unshelled pecans stored under ambient conditions after long-term storage.

1-Methylcyclopropene treatment alters fruit quality attributes and targeted metabolites in ‘Wonhwang’ pears during shelf life

‘Wonhwang’ pears are susceptible to the development of cortex and core browning after harvest. The effects of 1 μL L−1 1-methylcyclopropene (1-MCP) treatment on fruit quality, internal browning incidence, and targeted metabolites were evaluated in fruit stored at 25 °C for up to 30 d. Flesh firmness was higher in 1-MCP-treated fruit than in untreated fruit during storage; however, shrivelling increased in response to 1-MCP treatment. 1-MCP treatment delayed the changes in colour variables in core tissues but not in peel and cortex tissues, delayed cortex and core browning, and increased shrivelling. 1-MCP-treated fruit had higher sucrose, dehydroascorbic acid, alanine, threonine, and γ-aminobutyric acid contents and lower fructose and glucose contents than untreated fruit. The effects of 1-MCP on the physiological and metabolomic responses of fruit were detected using heatmap matrixes and by principal component analysis.

X-ray CT and porosity mapping to determine the effect of ‘Fuji’ apple morphological and microstructural properties on the incidence of CO2 induced internal browning

There is considerable variability in the distribution of porosity within a fruit, hence non-destructive methods to map porosity of the entire fruit are essential. The objective of this study was to use X-ray computed tomography (CT) to map the porosity of ‘Fuji’ apple and help determine the extent to which different fruit morphological and microstructural properties influence the susceptibility of the fruit to CO2 stress-induced internal browning (IB). X-ray CT based porosity mapping and high-resolution X-ray CT were used to determine porosity changes in fruit tissue following exposure to an atmosphere enriched with 50 % CO2 at room temperature (21 °C) for 3 d after harvest. Low-resolution X-ray CT scans enabled the construction of porosity maps for intact fruit based on a linear regression model and a juice scan which acted as a 0 % porosity reference. Short-term exposure of fruit to a high level of CO2 markedly induced IB in the core region of the fruit. Axial porosity profiles measured before the CO2 stress treatment showed that porosity along the axial plane was usually lower in fruit that developed IB. Larger sized fruit were more susceptible to the CO2 stress-induced IB disorder. The porosity in the IB affected fruit tissue declined from 8.6 to 5.4 % following the CO2 stress treatment. It is recommended to ensure that levels of CO2 and O2 in the controlled atmosphere (CA) storage environment are carefully controlled to minimize the risk of IB incidence.

Effect of exogenous putrescine treatment on internal browning and colour retention of pear fruit

The putrescine (PUT) efficacy in preserving the postharvest quality, regulating the bioactive compounds and internal browning (IB) was examined during ambient storage of pear fruit. To reduce the internal browning and preserve the colour of pear fruit during ambient storage, preharvest PUT @ 1 mM, 2 mM and 3 mM application was given 14 days before harvest and fruit were stored at ambient conditions (31 ± 2 °C, 78 ± 5% RH) for 15 days. PUT at 2 mM & 3 mM delayed the IB and reduced the polyphenoloxidase enzymatic activity compared with the control fruit. PUT also maintained total phenolics content and enhanced the peroxidase enzymatic activity. These treatments preserved chlorophyll content and suppressed the carotenoids synthesis led to delay in colour changes as compared with control. Results suggest that 2 mM & 3 mM PUT reduced IB incidence and PPO activity and maintained the pear fruit colour during ambient storage.

Adjustments of both phospholipids and sphingolipids contribute to cold tolerance in stony hard peach fruit by continuous ethylene

Horticultural products, including peaches, are susceptible to chilling injury (CI), on which the effect of ethylene is still controversial, and the underlying mechanism remains elusive. Here, changes in biochemical and molecular mechanisms involved in phenolic and lipid metabolism were compared between stony hard peaches with continuous ethylene (CETH) and controls. CETH effectively compromised internal browning incidence, accompanied by the inhibited activity of peroxidase but enhanced phenolic content, and less membrane leakage with reduced H2O2 and malondialdehyde contents. Intriguingly, CETH elevated levels of phospholipids and unsaturation of their acyl chains, coincident with the lower transcript levels of phospholipase Dα1 but higher fatty acid desaturase2/8.1, and the enhanced sphingolipid contents and biosynthesis concomitant with higher transcript levels of glucosylceramide synthase but lower inositol phosphorylceramide synthase3. Therefore, CETH can ameliorate fruit CI through adjusting phenolic and lipid metabolism, especially comprehensive remodeling of phospholipids and sphingolipids to contribute to the membrane stability.

Bagging cv. Fuji, Raku Raku Apple Fruit Affects Their Phenolic Profile and Antioxidant Capacity

The objective of the work was to assess the effects of bagging cv. Fuji, Raku Raku apple fruit on the phenolic compounds and antioxidant capacity of the peel using five-year-old trees on M 9 rootstock at San Clemente, Chile (35°S). Total phenolic concentrations were lower in bagged apple fruit than in unbagged control fruit. The antioxidant activity increased once the bags were removed and fruit exposed to light. Bagging also decreased the incidence of sunburn. Chlorogenic acid, catechin and phloridzin in the apple fruit peel were not affected by the bagging treatment. After anthocyanin, quercetins were the phenolic compounds most sensitive to bagging. Bagging neither affected maturity parameters nor their mineralogical composition. In terms of physiological disorders, bagging showed a tendency of decreased incidence of internal browning, but with more rotting.

Chilling injury alleviation of Queen pineapple cv. ‘Sawi’ fruit by acetyl salicylate immersion

Chilling injury (CI) is the main problem affecting quality of Queen pineapple (Ananas comosus L.) fruit during cold storage. The purpose of this paper was to investigate the application of acetyl salicylate (ASA) on CI alleviation of pineapple fruit cv. Sawi during storage at 13 ± 1 °C for 10 d. The pineapples were dipped in ASA solution at the concentrations of 2.5 or 5.0 mM for 1, 2 or 3 h and untreated fruits were used as control treatment. The biochemical-related parameters to CI incidence of tissue adjoining to the core were determined after the fruits were left at 25 °C for 2 d. The results show that 5.0 mM ASA immersion for 1 h alleviated internal browning incidence and lowered CI score compared to other treatments. The treatment also maintained high lightness (L*) value and low colour difference (ΔE*) value of tissue adjoining to the core. Compared to control treatment, the 5.0 mM ASA immersion lowered browning index, malondialdehyde concentration, polyphenol oxidase activity and TP concentration as well as increased antioxidant capacity and ascorbic acid concentrations of tissue adjoining to the core. Therefore, 5.0 mM ASA immersion for 1 h is an effective alternative alleviating CI of Queen pineapples during cold storage.

The effect of methyl jasmonate on internal browning incidence and postharvest quality of 'Huai-mun’ pineapple fruit

The effect of methyl jasmonate (MeJA) on internal browning (IB) and postharvest quality of ‘Huai-mun’ pineapple fruit was investigated. Fruit were harvested at the green mature stage and dipped in MeJA at concentrations of 0 (control), 10‑2, 10‑3 and 10‑4 M for 5 min prior to storage at 10°C for four weeks. Each week, fruit were randomly removed to room temperature for ripening prior to fruit quality determinations. A completely randomized experiment was conducted with four replications (1 fruit/replication). Data analysis was performed by using ANOVA and means were compared by using DMRT at 95% confidence level. MeJA did not reduce IB development in this study. The internal browning (IB) symptoms limited storage life to only 1.25 weeks after treatment with 10(‑2) M MeJA while it was 1.5 weeks in control fruit and in 10(‑3) M MeJA. A concentration of 10(‑4) M MeJA enabled fruit to be stored for 2.5 weeks. In addition, MeJA significantly (p 0.05) difference. Therefore, the application of 10(‑4) M MeJA could maintain the quality of ‘Huai-mun’ pineapple fruit harvested at a mature green stage for up to 2.5 weeks at low temperature.

Effects of Potassium Fertilization for Pineapple on Internal Browning of Fruit in Post-Harvest Conservation

Resistance to internal browning of pineapple fruits depends on several factors such as the cultural techniques through mineral fertilization. The objective of this work is to study the effects of the potassium fertilization for pineapple on internal browning of fruit in post-harvest conservation. The experiments have been carried out on the site of the University Nangui Abrogoua (Abidjan, Côte d’Ivoire) of July 2015 to the end of October 2016. Potassium has been applied according to four modalities of treatments (T0; T1; T2 and T3) made in 2nd, 4, 6 and 7th months (respectively) after plantation. The incidence of internal browning (IB), the phenolic content, sugars and ascorbic acid have been determined after post-harvest conservation of fruit. The activity of phenolic biosynthesis enzymes (PAL and TAL) and oxidation enzymes (PPO and POD) were evaluated. The results showed that BI intensity in pineapple fruit decreases with the potassium amount applied in field. This IB drop was correlated with the content of reducing sugars, total phenols, activity of PAL and the PPO. No symptom of IB was observed on pineapple fruits under treatment T2 (34 g of K2O/plant). Potassium has a depressive effect on phenolic biosynthesis. In effect, it inhibits the IB in the both varieties of pineapple studied that are Smooth Cayenne and MD2.

Internal browning alleviation of Queen pineapple cv. ‘Sawi’ under cold storage using salicylic acid or abscisic acid peduncle infiltration

ABSTRACTInternal browning (IB) is a main problem of Queen pineapple during cold storage. The effects of exogenous salicylic acid (SA) or abscisic acid (ABA) on IB alleviation of the pineapple during cold storage were investigated. ‘Sawi’ pineapples were peduncle-infiltrated with 2 mM SA or 380 µM ABA for 3 d at 13°C followed storage at 13°C for 14 d. IB incidence and IB-related factors including lipid peroxidation, antioxidant capacity and antioxidant enzymes activities of the tissue adjacent to core were investigated after storage for 7 and 14 d followed by 2 d at room temperature (RT). Both SA and ABA treatments obviously alleviated IB development. ABA lowered TP content, MDA accumulation and the activities of LOX, PAL and PPO and induced POD activity. SA lowered PAL and PPO activity, delayed LOX activity and MDA increase, enhanced phenols, antioxidant activity and both antioxidant enzyme yields. Both ABA and SA peduncle infiltration alleviated IB incidence of Queen pineapple during cold storage. Although ABA could reduce the IB incidence better than SA, due to the efficiency of lower reactions of browning-related enzymes and lipid peroxidation, exogenous SA application might be a better choice for commercial use.Abbreviations: Total phenols (TP), Malondialdehyde (MDA), Lipoxygenase (LOX), Phenylalanine ammonia lyase (PAL), Polyphenol oxidase (PPO), Peroxidase (POD) and Internal browning (IB)