Granny Smith Research Articles

An Empirical Model for Predicting the Fresh Food Quality Changes during Storage.

It is widely recognized that the quality of fruits and vegetables can be altered during transportation and storage. Firmness and loss of weight are the crucial attributes used to evaluate the quality of various fruits, as many other quality attributes are related to these two attributes. These properties are influenced by the surrounding environment and preservation conditions. Limited research has been conducted to accurately predict the quality attributes during transport and storage as a function of storage conditions. In this research, extensive experimental investigations have been conducted on the changes in quality attributes of four fresh apple cultivars (Granny Smith, Royal Gala, Pink Lady, and Red Delicious) during transportation and storage. The study evaluated the weight loss and change in firmness of these apples varieties at different cooling temperatures ranging from 2 °C to 8 °C to assess the impact of storing at these temperatures on the quality attributes. The results indicate that the firmness of each cultivar continuously decreased over time, with the R2 values ranging from 0.9489-0.8691 for red delicious, 0.9871-0.9129 for royal gala, 0.9972-0.9647 for pink lady, and 0.9964-0.9484 for granny smith. The rate of weight loss followed an increasing trend with time, and the high R2 values indicate a strong correlation. The degradation of quality was evident in all four cultivars, with temperature having a significant impact on firmness. The decline in firmness was found to be minimal at 2 °C, but increased as the storage temperature increased. The loss of firmness also varied among the four cultivars. For instance, when stored at 2 °C, the firmness of pink lady decreased from an initial value of 8.69 kg·cm2 to 7.89 kg·cm2 in 48 h, while the firmness of the same cultivar decreased from 7.86 kg·cm2 to 6.81 kg·cm2 after the same duration of storage. Based on the experimental results, a multiple regression quality prediction model was developed as a function of temperature and time. The proposed models were validated using a new set of experimental data. The correlation between the predicted and experimental values was found to be excellent. The linear regression equation yielded an R2 value of 0.9544, indicating a high degree of accuracy. The model can assist stakeholders in the fruit and fresh produce industry in anticipating quality changes at different storage stages based on the storage conditions.

New trends of apple (Malus domestica) production: A review

Apple (Malus domestica) belongs to rose family Rosaceae of Angiosperms. Apple farming is an important activity and profession of farmer communities in the Himalayan states of India. China is the world’s largest producer of apples while India holds the second place in world trade market. The most common verities of apples in India are Red Delicious and Granny Smith. In North West Hill Region, Jammu and Kashmir contributes 80% of India’s apple production, Himachal Pradesh which is the second largest producer accounts for 12.5% and Uttarakhand produces 5% of India’s apples. In North East Hill Region, Arunachal Pradesh is the only major apple producing state outside the north-western hill region in the country producing Black Bendavis, Royal gala, Jonathan, Red Gold, Gani Gala, Rich-A-Red, Royal delicious, Red delicious, Golden delicious, Cooper- IV, McIntosh, Crofton, Granny smith, Starkrimson, Fokla, Ruspippin, Rajakori, Ganu and Mutsu apple varieties. The apples are a great source of fiber and pectin, and helps in controlling insulin levels, acts as anti cancerous, anti cholesterol and reduce risk of asthma and diabetes. The majority of farmers at low altitude and mid altitude reported decline in apple farming whereas 71% farmers at high hill areas refused decline in apple farming. About 73–83% farmers admitted delay in apple’s harvesting period. At mid hills apple scab and at low hills pest attack on apple crops are considered as the indicators of climate change.

Determination of the ursolic and oleanolic acids content with the antioxidant capacity in apple peel extract of various cultivars.

Apples are rich sources of ursolic acid (UA) and oleanolic acid (OA) which are the major and most prominent triterpenes in the peel of an apple. Pentacyclic triterpenes are ideal nutraceuticals due to their ability to reduce the risk of many life-threatening diseases such as cancer, cardiovascular and diabetes. This study was to determine the content of UA and OA in the apple peel extract from different cultivars grown in South Africa as well as the correlation of their content level with antioxidant capacity. Quantitative analysis of UA and OA in apple peels from three cultivars; red delicious (RD), royal gala (RG) and granny smith (GS) apples was carried out using HPLC and their antioxidant capacity was analyzed using the DPPH assay. The RD showed the highest content of UA and OA (248.02 ± 0.08 µg/ml and 110.00 ± 0.08 µg/ml respectively) in the apple peel extract and also displayed a significantly high level of antioxidant capacity (97.3 ± 0.40%; p < 0.0001) compared to the RG and GS cultivars. A strong positive correlation was noted between the UA, OA and antioxidant capacities of all the cultivars. Only the RD cultivar showed a significant correlation though; UA (r = 0.9570; p = 0.0027) and OA (r = 0.8503; p = 0.0319). This study demonstrated that the RD and RG apple peels possess the highest UA and OA content which invariably increases their antioxidant activities compared to GS apple. Thus, both apple cultivars would be useful and recommended for food consumption and nutraceuticals values to improve human health.

Influence of Different Calcium Compounds and Fruit Development Stages on Yield, Fruit Quality and Shelf Life of ‘Granny Smith’ Apples

Calcium (Ca) plays major roles on the storage life and quality apples. In this study, the influence of calcium chloride (CaCl2) and two organic calcium compounds including Calcicat and Folical at four different times of application on the quality and shelf life of ‘Granny Smith’ apples during two growing seasons. Quantitative and qualitative attributes were evaluated at harvest and after three- and six-months cold storage. In the first year, Folical all-season and mid-season sprays resulted in a significant increase in Ca concentration. In the second year, early-season spray resulted in significant Ca increase compared to control. In the first year, the early-season spray program of Folical had the highest yield and fruit weight. The use of calcium compounds in all timing programs reduced fruits soluble solids concentration (SSC) at harvest compared to control treatments. In both years, at harvest, no significant difference was observed among treatments regarding the ‘Granny smith’ apple firmness. In the first year, the chlorophyll content of ‘Granny Smith’ apple peels were affected by spray timing and the type of calcium compound. In both years, Fruits treated with Ca had lower ethylene concentration and brightness index (L*) than controls. In the second year, Folical spray decreased the percentage of superficial scald incidence for three months storage. During the first year, all-season Calcicat spray and in the second year early-season Folical spray showed the lowest percentage of scald disorder after six months storage. In the first year, the all-season spray program and in the second year Folical spray decreased the severity of scald after three months of storage.

The Effect of Variations in Fresh-Cut Apple Composition on the Performance of Polyvinyl Chloride Active Films

Enzymatic browning is one of the limiting factors in extending the shelf-life of food products. Since the chemical composition can differ depending on fruit species and variety, browning prevention treatments may not always present the same efficacy. The goal of this study was to verify if differences between two fresh-cut apple varieties, Granny Smith (GS) and Red Delicious (RD), would affect the performance of polyvinyl chloride (PVC) active films for avoiding browning. Three active components were individually introduced in PVC films, i.e., citric acid, ascorbic acid, and tocopherol. Kinetics studies confirmed that browning behavior was affected by the apple variety. In the case of refrigerated RD apples, all films were able reduce browning, in the following order: ascorbic acid > citric acid > tocopherol. For GS samples, on the other hand, none of the active films was able to avoid browning. Oxidation test results showed that significant protective action occurred for the following phenolics, regardless of apple variety: chlorogenic acid, catechin, epicatechin, and gallic acid. In RD apples, there was protective effect also for procyanidin B2 and ethyl gallate, and in GS samples for ferulic, caffeic, and protocatechuic acids. The browning kinetic rates demonstrated the effectiveness of the produced films, despite the distinct browning behavior of the two varieties. The ascorbic acid–laden films presented an overall better performance in comparison to the other active films in controlling the enzymatic browning of apples.

Phytochemicals and antioxidant activity of different apple cultivars grown in South Ethiopia: case of the wolayta zone

ABSTRACT Apple fruit is one of the most intensively grown and widely cultivated fruit crop in the temperate regions around the world. This study investigated sugar, vitamin C, total phenolic contents (TPC), total flavonoid contents (TFC), and antioxidant activity of three varieties (Golden delicious, Fuji rose, and Granny smith) of whole apple fruits (peel and flesh). Total sugar, reducing sugar and sucrose contents were determined by Lane and Enyon method. Folin-Ciocalteu and aluminum chloride, and standardized iodine solutions were used to determine TPC, TFC, and vitamin C, respectively. Antioxidant activity was determined using 2, 2-Diphenyl-1-Picryl-Hydrazyl (DPPH) scavenging, total antioxidant and ferric ion reducing power assays. It was found that Golden delicious cultivar contained the highest amount of total sugar (17.32 ± 0.40 mg/100 g juice) and reducing sugar (10.04 ± 0.30 mg/100 g juice), whereas the juice of Fuji rose variety had the highest amount of sucrose (6.90 ± 0.35 mg/100 g of juice). The Granny Smith variety had the highest TPC (71.88 ± 2.30 mg gallic acid equivalent per gram of dried extract) whereas the Fuji rose had the highest TFC (21.91 ± 2.55-mg catechin equivalent per gram of dried extract). The Golden delicious cultivar had the highest vitamin C (31.48 ± 2.18 mg/100 g of juice). The Fuji rose showed the strongest DPPH radical scavenging activity (EC50 = 86.20 ± 2.28 µg/mL), iron reducing power (EC50 = 1.93 ± 0.66 mg/mL), and total antioxidant activity (0.46 ± 0.08 mg butylated hydroxy toluene equivalent/g of dried extract). Based on the present investigation, it can be concluded that the significant differences in the phytochemical composition and antioxidant activity of apple fruits could be attributed to varietal differences.

Extraction of polyphenols using afroyal gala and granny smith for antimicrobial activity

Apples contain many useful human health-related contents. Polyphenols exhibit antimicrobial effects against human pathogens. In this study, the polyphenolic contents are removed by the skin of Royal Gala and Granny Smith, which are the two varieties of apples. The phenolic compounds were removed from fresh fruit peels of Royal Gala and Granny Smith with the solvents: A-(water), B- (ethanol: water). The antimicrobial happenings of the excerpts are verified in contradiction of Escherichia coli and Staphylococcus aureus bacteria by jelly healthy dispersion technique. The extracts from both apples by solvent A presented advanced anti micro bisection as associated with excerpts by solvent B. Among the 2 varieties of apples, the Granny Smith extracts presented a superior antimicrobial result as compared to Royal Gala extracts against the selected microorganisms E-coli and S -aureus. The zone of inhibition by the apple peel extracts is more in case of S -aureus compared with E-coli; this reveals that the organism S-aureus is more sensitive to polyphenolic compounds than Escherichia coli. With this study, it was concluded that the water extract of Granny Smith peels showed superior antimicrobial movement because of advanced amounts of polyphenolic mixtures as associated to Royal Gala and the best solvent to extract polyphenolic compounds from apple peels is water.

Preservation of Aloe vera and soybean flour fortified Granny Smith apple through optimised quartz–halogen radiated vacuum drying: kinetics and quality evaluation

Granny Smith (GS) apple has low protein content and poor antimicrobial properties; hence it has been blended with Aloe vera (AV; high ascorbic acid, antimicrobial and antioxidant properties) and soybean flour (SF; rich in phenols, flavonoids, ascorbic acid, total antioxidant and protein) in different proportions to obtain fortified GS, i.e. GSAVSF. Moreover, GS being a perishable fruit, its moisture content should be reduced to enhance shelf life. Accordingly, this GSAVSF was osmotically pre-dehydrated and finally dried through energy-efficient quartz-halogen radiation (QHR) assisted vacuum-drying (QHRVD) to produce dried GSAVSF i.e. (DGSAVSF) under optimized conditions. The optimally dehydrated DGSAVSF product resulted in minimum moisture (4.85% w/w) and maximum protein (6.24 g kg-1 ) content. The application of osmotic dehydration and QHRVD afforded acceptable colour of DGSAVSF compared to GSAVSF (ΔEI * = 10.07 ± 0.21). A parametric drying model was formulated that corroborated well with Fick's equation. QHRVD rendered high moisture diffusivity (1.49 × 10-8 m2 s-1 ) and low activation energy (27.64 kJ mol-1 K-1 ). Appreciable quality improvements with respect to fresh GS concerning ascorbic acid (176.05%), total phenolic (579.07%), total flavonoid (333.33%) contents and 2,2'-diphenyl-1-picrylhydrazyl radical scavenging activity (446.71%) could be achieved. The product demonstrated satisfactory shelf life (1 × 104 CFU g-1 : aerobic mesophilic; 1 × 104 CFU g-1 : mould and yeast) and high rehydration ratio (4.25 ± 0.1). The enrichment of GS with AV and SF along with optimal drying protocols could provide a quality fortified DGSAVSF through an energy-proficient sustainable process. The highly nutritious product with suitable colour, microbial stability and rehydration ratio also satisfied a 9-point hedonic scale, thus confirming consumer acceptability. © 2020 Society of Chemical Industry.

Apple Supplementation Improves Hemodynamic Parameter and Attenuates Atherosclerosis in High-Fat Diet-Fed Apolipoprotein E-Knockout Mice.

Epidemiological studies describe the association between apple consumption and improved cardiovascular and metabolic dysfunction. Our recent multiparametric screening on cellular model studies has shown that apples exhibit vascular tropism including Granny Smith (GS) variety independently of the storage condition. The present study aimed to evaluate the cardiovascular and metabolic protection of supplementation of GS variety after storage in classic cold (GSCC) and extreme ultra-low oxygen conditions (GSXO) in the apolipoprotein E-deficient 8-week-old mice fed with high fat diet for 14 weeks. Supplementation with GSCC and GXO decreases circulating triglycerides, the expression of genes involved in lipogenesis, without change in cholesterol and glucose concentrations and HOMA-IR. Only GSXO supplementation ameliorates body weight gain, insulin level, and HDL/LDL ratio. GSXO supplementation does not modify cardiac parameters; while supplementation with GSCC decreases heart rate and improves cardiac output. Interestingly, GSCC and GSXO reduce systolic and diastolic blood pressure with a differential time course of action. These effects are associated with substantial decrease of atherosclerotic lesions. These data reinforce the knowledge about the vascular tropism of apple supplementation and underscore their ability to improve both cardiovascular and metabolic alterations in a mouse model of atherosclerosis.

DISTRIBUTION OF ROOT SYSTEM AT APPLE CV. GRANNY SMITH GRAFTED ON DIFFERENT DWARFING ROOTSTOCKS

This paper analyses the distribution of root systems of nine dwarf apple rootstocks (M.9 T 984, M.9 T 337, Jork 9, Mark 9, Budagowski 9, M.9 EMLA, Pajam 1, Pajam 2 and Supporter 4). All rootstocks were grafted with apple cultivar Granny Smith. The study was performed in the experimental orchard established in the Prespa region (Resen, R. Macedonia). The experimental orchard was established in 2004, with a planting distance 3.5 m x 1.5 m. At the end of the 7th growing season following characteristics were evaluated: length and weight of the fine (fibrous) and coarse roots, and depth distribution of the root system. Among the evaluated rootstocks statistically significant differ-ences in total length of the fine roots were not found. Between different rootstocks the results for total length of coarse roots showed more variability. In general, even 89% of the total length of root system belonged to fine roots, and the highest percentage (35%) was located at depths of 20 to 40 cm. Trees grafted on Mark 9 rootstock had the highest value for total root length, while the smallest values were registered on those grafted on Pajam 1 rootstock. Trees grafted on Supporter 4 rootstock had the greatest weight of the root system, while the smallest one was found on rootstock Budagowski 9.

Evaluation the Preharvest Application of Iron and Nitrogen on Some Qualitative Characteristics of Two Apple Cultivars during Cold Storage

Apple is one of the most important fruits in temperate zones with a long post-harvest life during cold storage. A factorial experiment, in a randomized completely block design was used to investigate the preharvest application of Iron (0, 500 and 1000 mg Fe-EDDHA per tree) and nitrogen (0, 48 and 96 g ammonium nitrate per tree( on some postharvest qualitative characteristics in Red spur and Granny smith apple cultivars. Iron and nitrogen treatments in all 72 trees were applied in three stages (full bloom, 30 and 60 days after full bloom). Fruit quality parameters including colorskin color parameters (L*, a*, b*), flesh firmness, total soluble solids (TSS), Titratable acidity (TA), flavor index (TSS/TA) and total antioxidant activity were measured. According to the results, a decrease in fruit firmness, TA and increase in TSS/TA in both cultivars were observed during cold storage irrespective of treatments. The results showed that in “Red spur” cultivar, Fe application decreased fruit firmness, TSS, b* parameter values and increased TSS/TA, a* parameter values, while, N application increased TSS. Fruit firmness was decreased and TSS, TSS/TA, b* parameter values were increased by Fe application in “Granny smith” cultivar. Fruit firmness, TSS and L* parameter values were decreased and TA was increased by N application on this cultivar. In conclusion, Fe and N application in proper levels improved some postharvest qualitative characteristics in Red spur and Granny smith apple cultivars during cold storage.

Effect of high pressure on mass transfer kinetics of granny smith apple

ABSTRACTThe mass transfer kinetics during osmotic dehydration of granny smith apple slices in 60 Brix fructose and sucrose solution was studied at atmospheric pressure and at elevated pressure of 200–600 MPa at 40°C. The moisture and solute fractions in apple slices during osmotic dehydration under high pressure were predicted by Weibull frequency distribution model. The calculated effective moisture diffusivity values of apple slices suspended in fructose and sucrose solution during high-pressure treatment (0.1–600 MPa) were in the range of 6.35 × 10−10 to 3.60 × 10−9 m2/s and 7.96 × 10−10 to 4.32 × 10−9 m2/s, respectively.

Development of realistic food microstructure considering the structural heterogeneity of cells and intercellular space

Abstract The geometric characterization of the microstructure is required to model the micro level transport process inside the plant-based food material during thermal processing. However, the existing geometric construction methods are unable to consider the distinctive geometrical characteristics of cells and intercellular spaces during generation of the virtual microstructure. The main aim of this study is to develop a new method to build microstructure of the plant-based food materials with clear identification of cell and intercellular spaces. Granny smith and red delicious apple were taken as samples to implement and validate the proposed method. The virtual microstructure was generated from the scanning electron microscope image (SEM) of the apples. A new algorithm was developed based on the modified ellipse fitting method to generate the microstructure from microscopic images. Linear Discriminant Analysis (LDA) was used to classify the cells and the intercellular spaces. Statistical analysis was performed between the developed geometrical model and microscopic image to determine the accuracy of the proposed method. The area distribution of the microstructural model found in this study is significantly better than that found in the literature.

Comparison of biochemical properties and thermal inactivation of membrane‐bound polyphenol oxidase from three apple cultivars (Malus domestica Borkh)

SummaryA comparative study of the properties of membrane‐bound polyphenol oxidase (mPPO) from three apple cultivars, namely Red Fuji (FJ), Granny Smith (GS) and Golden Delicious (GD), was carried out for the first time. Data indicate that mPPOs from three cultivars exhibit significantly different properties. GS mPPO had the strongest affinity to catechol, but FJ mPPO had the highest maximum velocity. Red Fuji (FJ) mPPO had the significantly higher activity than those of GD and GS mPPOs. Red Fuji (FJ) mPPO had the highest activity at pH 8.00, while GD and GS mPPOs at 4.50 and 7.50–8.00, respectively. Red Fuji (FJ) mPPO was more stable than GD and GS mPPOs over the pH range of 5.0–8.5. The optimal temperature for GS mPPO was within 70–75 °C, which is higher than those for mPPOs from FJ and GD. Thermal inactivation of the three mPPOs followed a first‐order kinetic model with different inactivation kinetic parameters.

Anomalous diffusion based on fractional calculus approach applied to drying analysis of apple slices: The effects of relative humidity and temperature

AbstractThe objective of this research was to evaluate the diffusion mechanism based on Fick's second law and anomalous diffusion modifying the drying operating conditions temperature (T) and relative humidity (RH) on apple slices (cv. Granny smith). Drying was performed at 30 °C, 40 °C, 50 °C and 30%, 50%, 70%RH based on a 32 experimental design. The drying curves were analyzed to determine the effective diffusion (Deff) using two methods: Fick's second law and anomalous diffusion model based on fractional calculus approach. Our results showed that the anomalous diffusion mechanism fit the experimental data better and revealed a super‐diffusive behavior (α &gt; 1). Therefore, Deff values were estimated using the anomalous diffusion model with α = 1.735. With respect to the use of anomalous diffusion model solution based on fractional calculus at different operations conditions allow to get better fitting of drying data than second Fick's law model, even keeping the Arrhenius behavior of Deff with temperature.Practical applicationsDiffusion process is typically analyzed using models based on Fick's second law. However, several assumptions inherent in Fick's second law are not fulfilled in food materials (e.g., structural heterogeneity). In addition, Fick's second law does not consider structural variations during the drying process, and it is well known that fruits such as apples experience significant structural changes during drying. Fractional calculus is a tool for mathematically representing the anomalous diffusion of solutes whose movements can be faster or slower than postulated in Fick's second law due to food structure. In general, with second Fick's law model not good fitting to data are obtained, therefore the prediction capacity of the model is limited. Based on this, anomalous diffusion solution based on fractional calculus was applied. The results showed good fit the data to the model, and also by the time exponent (α) is possible to identify the kind of diffusion process.

Investigation of responses of some apple (Mallus x domestica Borkh.) cultivars grafted on MM106 and M9 rootstocks to lime-induced chlorosis and oxidative stress

The response of dwarf (M9) and semi dwarf (MM106) clonal apple rootstocks and 5 apple cultivars [Granny Smith (GS), Fuji (F), Royal Gala (RG), Mondial Gala (MG) and Red Chief (RC)] grafted on these rootstocks to lime induced iron chlorosis and iron deficiency induced oxidative stress were investigated. Both rootstocks and cultivars were divided into two groups. One of the group were kept as control group. To the second group, to ensure the lime-induced chlorosis, bicarbonate (HCO3−) was applied. Both groups were grown for two years in a pot experiment. The soil used in the experiment was a clay loam calcareous soil containing 70.9gkg−1 lime. To evaluate the lime-induced chlorosis effects on both rootstocks and cultivars, accumulation of H2O2 and membrane damage (MDA, lipid peroxidation), activities of catalase (CAT, EC 1.11.1.6), superoxide dismutase (SOD, EC 1.15.1.1) and ascorbate peroxidase (APX, EC 1.11.1.11) determined. Bicarbonate treatment reduced active and total Fe and total chlorophyll concentrations, and FCR (leaf ferric chelate reductase) activity while increased the MDA, H2O2, SOD and APX activity of cultivars and rootstocks in both years. These changes and the statistical significances of individual and combined effects of treatment and cultivar or rootstocks showed great differences among the cultivars and rootstocks. So B/C rates helped us to evaluate the tolerance to lime induced chlorosis of the cultivars and rootstocks. B/C referring Fe efficiency ratio calculated as the value for the bicarbonate treatment divided by that for the control for each parameter studied used for tolerance state of cultivars and rootstocks. According to B/C ratios calculated for active and total Fe, FCR, the MG and RG grafted on both rootstocks regarded as tolerant cultivars. In addition to this, the MM106 rootstock was more tolerant than the M9 rootstock under bicarbonate applied condition giving higher B/C ratio for active and total Fe, total chlorophyll, FCR and APX but lower MDA concentrations. It can be concluded that suitable cultivar-rootstock combinations is a good strategy to overcome Fe chlorosis in apple plants grown in calcareous soils.

Total Phenolics Content, Antioxidant Capacity, Physicochemical Attributes, and Browning Susceptibility of Different Apple Cultivars for Minimal Processing

ABSTRACTThe total phenolics content, browning susceptibility, antioxidant capacity, and other physicochemical attributes of five cultivars of apple with different chilling hours requirements were studied to be minimally processed. Granny Smith (GS) and Red Delicious (RD) cultivars (high chill requirement), and Caricia (C), Eva (E), and Princesa (P) cultivars (low chill requirement) were studied. The flesh color, firmness, juiciness, pH, acidity, soluble solids, and flesh browning development, and total phenolics content and antioxidant capacity in flesh and peel were determined. All attributes were significantly different (p ≤ 0.001) among cultivars. RD showed the highest values of soluble solids and pH, and GS, the lowest. GS and P had the highest values of firmness and juiciness. GS, P, and E showed the lowest browning development. RD had the highest phenol content in flesh, followed by E and C. Phenolic content in peel was 2–5 times higher than in flesh for all varieties. The antioxidant capacity of RD flesh was higher than the other four apple cultivars. The antioxidant capacity of the apple peel was 2–4 times higher than the flesh, being RD the highest, followed by C, GS, and P with 50% less. Considering the lower browning development, and higher values of firmness and juiciness, GS and P would be the most suitable cultivars for minimal processing. If fresh-cut apples are not peeled, GS and P would increase their phenolic content in 28–56% and their antioxidant capacity in 65–78%.

Involvement of protective enzymes and phenols in decay (Penicillium expansum) resistance in apple

Blue mold disease caused by Penicillium expansum is a major post- harvest disease of apples. In this research, the biochemical basis of apple resistance to this pathogen was studied in two relatively resistant and susceptible cultivars, Granny smith and Mashhad, respectively. The activities of catalase (CAT), peroxidase (POX), superoxide dismutase (SOD) and polyphenol oxidase (PPO) enzymes and polyphenol content were compared at different time intervals of 0 to 7 days. Based on the results, fruit polyphenol content of Granny smith was higher than that of Mashhad PPO, SOD and CAT activity was higher in Granny smith than Mashhad but CAT activity decreased three days post-treatment. No detectable difference was found in POX activities in the two cultivars. It is concluded that polyphenols contribute in apple resistance to blue mold. Activation of PPO and SOD, lack of POX activity and decrease of CAT activity, all together, could lead to a toxic environment around the blue mold fungus.

Effects of decreasing levels of n amendments on organic &amp;#8220;granny smith&amp;#8221; apple trees

The effect of decreasing levels of organic N-fertilization on fruit production, mineral composition and fruit quality was evaluated in organically cultivated “Granny Smith” apples trees. Treatments included the application of decreasing levels of N fertilization (100 kg N ha-1, 75 kg N ha-1, 50 kg N ha-1 and 0 kg N ha-1 ) applied as fossilized red guano (50% of the total amount of N) and blood meal (50% of the total amount of N) to twelve years old Granny Smith apple trees. Yield was not affected by the treatments (yield ranged from 0.28 to 0.4 kg cm-2 SCSA). Fruit mineral concentration and ratios were not affected by treatments. Fruits showed low Ca concentrations (2.8 to 3.3 mg Ca 100 g-1 FW), high levels of K (118.6 to 130.1 mg K 100 g-1 FW) and high values for K+Mg/Ca (> 12) and K/Ca (> 30) ratios. Mineral concentration on leaves was not affected by treatments (normal concentrations for macro and microelements). Bitter pit was only detected after 60 days of storage (100 kg N ha-1 tree, 1.1 in a scale 1-4). Besides orchard nitrogen management, fruit mineral ratios and Ca foliar applications should be considered for managing fruit production and quality in organic apples.

Analysis by non-linear irreversible thermodynamics of compositional and structural changes occurred during air drying of vacuum impregnated apple (cv. Granny smith): Calcium and trehalose effects

Apple discs were impregnated with isotonic solutions of sucrose and trehalose with and without calcium addition and after air dried. In the vacuum impregnation experiments, the calcium and the replacement of sucrose by trehalose did not have significant effect on the final volumetric deformation of the samples. During air drying two stages of changes were considered. The first one lasted until the saturation of the intracellular liquid phase, and the second one from the saturation of the intracellular liquid phase until the end of the drying process. Mass transfer has been analysed applying nonlinear irreversible thermodynamics. Water flux, water chemical potential and tissue shrinkage have been taken into account in order to accurately describe the mass transfer phenomena during air drying. A precise definition of chemical potential allowed estimating the partial molar energy needed for breakages and the reversible and irreversible deformations of tissue structure coupled with mass transfer during air drying of apple.