Bravo De Esmolfe Research Articles

Antibacterial Activity of ZnO Nanoparticles in a Staphylococcus-aureus-Infected Galleria mellonella Model Is Tuned by Different Apple-Derived Phytocargos.

This research investigates pH changes during the green synthesis of ZnO nanoparticles (NPs) and emphasises its importance in their physicochemical, antibacterial, and biological properties. Varying the synthesis pH from 8 to 12 using "Bravo de Esmolfe" apple extracts neither affected the morphology nor crystallinity of ZnO but impacted NP phytochemical loads. This difference is because alkaline hydrolysis of phytochemicals occurred with increasing pH, resulting in BE-ZnO with distinct phytocargos. To determine the toxicity of BE-ZnO NPs, Galleria mellonella was used as an alternative to non-rodent models. These assays showed no adverse effects on larvae up to a concentration of 200 mg/kg and that NPs excess was relieved by faeces and silk fibres. This was evaluated by utilising fluorescence-lifetime imaging microscopy (FLIM) to track NPs' intrinsic fluorescence. The antibacterial efficacy against Staphylococcus aureus was higher for BE-ZnO12 than for BE-ZnO8; however, a different trend was attained in an in vivo infection model. This result may be related to NPs' residence in larvae haemocytes, modulated by their phytocargos. This research demonstrates, for the first time, the potential of green synthesis to modulate the biosafety and antibacterial activity of NPs in an advanced G. mellonella infection model. These findings support future strategies to overcome antimicrobial resistance by utilizing distinct phytocargos to modulate NPs' action over time.

Bioactive Compounds of Portuguese Fruits with PDO and PGI.

The European Union has established two designations, Protected Designation of Origin (PDO) and Protected Geographical Indication (PGI), to guarantee the authenticity of products with valued specificities associated with the regions where they are produced. The valorization of these products, particularly fruits, not only preserves their natural origins but also promotes the cultivalion of specific regional fruit varieties. This contributes to the preservation of biodiversity and the development of innovative bio-based products in the regions of production. In recent years, substantial efforts have been made to characterize PDO and PGI fruits, particularly in relation to the presence of bioactive compounds with antioxidant and antimicrobial properties. Portugal, with its diverse range of climates and geographical characteristics, is home to numerous fruits with unique flavors, textures, and appearances, many of which are now recognized with PDO or PGI seals. This review compiles data from the production of Portuguese fruits with PDO designations, such as the 'Maça Bravo de Esmolfe' (apple) and 'Pera Rocha do Oeste' (pear), and PGI designations, such as 'Citrinos do Algarve' (citrus)and 'Cereja da Cova da Beira' (cherry), and summarizes studies focusing on the bioactive compounds present in these fruits. The presence of bioactive compounds is a significant aspect of nutritious food, associated with health benefits that consumers are increasingly aware of and value.

Effective moisture diffusivity prediction in two Portuguese fruit cultivars (Bravo de Esmolfe apple and Madeira banana) using drying kinetics data

Air convective dehydration was performed at various temperatures (35 °C, 40 °C, 45 °C and 50 °C) using two types of fruits cultivars produced in different regions of Portugal: the Bravo de Esmolfe apple, from the Beiras province, and the Cavendish banana, from Madeira Island. The data collected were used to predict the effective moisture diffusion, which is a crucial input parameter in drying modeling and design. As expected, the values obtained in both falling drying rate periods detected for apples increased with an increase in drying temperature. The effective moisture diffusion in apples varied from 1.968 × 10−10 m2 s−1 at 35 °C to 4.013 × 10−10 m2 s−1 at 50 °C, for the first falling drying rate period, and from 0.9567 × 10−10 m2 s−1 at 35 °C to 3.328 × 10−10 m2 s−1 at 50 °C, for the second period. The dependence of effective moisture diffusion on temperature for bananas is similar, ranging from 1.572 × 10−10 to 2.627 × 10−10 m2 s−1 as the drying temperature changed from 35 to 50 °C.

Drying kinetics of two fruits Portuguese cultivars (Bravo de Esmolfe apple and Madeira banana): An experimental study

Air convective dehydration was carried out at a laboratory scale using two fruits of cultivars produced in different regions of Portugal: Bravo de Esmolfe apple, from Beiras province, and Cavendish banana, from Madeira Island. Fresh fruits were dried in a tray drier with a hot airstream at different temperatures (35, 40, 45, and 50 °C) and velocity of 1.6 m s−1. Drying rate curves were obtained using a simple mathematical approach applied to the moisture content curves adjusting linear and polynomial functions. Different drying rate stages were noticed in the experiments made with apples (one constant drying rate period followed by two falling drying rate periods), while in the case of the banana the constant drying rate period was not perceived, being dried entirely during a unique falling drying rate period. As expected, the constant drying rate value obtained at the beginning of the experiments with apples is higher when these were conducted at higher temperatures, changing from 8.103 to 14.474 g m−2 s−1 when the airstream temperature increases from 35 to 50 °C. The correspondent critical moisture contents in the Bravo de Esmolfe apples, at the instant the constant drying rate period stops and the drying rate starts to fall, slightly decreases from 4.800 to 4.134 kgwater/kgdry solid.This study explored for the first time the drying behavior of these two important fruits that have been increasingly used in the food industry in Portugal, giving important information for the industrialization of its production.

Using High-Pressure Technology to Develop Antioxidant-Rich Extracts from Bravo de Esmolfe Apple Residues.

Bravo de Esmolfe (BE) is a traditional Portuguese apple highly appreciated by consumers due to its peculiar flavor and aroma. This apple contains higher concentration of phenolic compounds than other cultivars and is thus considered a rich source of antioxidants. Its sensorial and functional properties have attracted farmers’ associations to increase BE production. However, a large quantity of apples is wasted due to storage/transportation procedures that impact BE’s quality attributes. In this work, we applied high-pressure extraction methodologies to generate antioxidant-rich fractions from BE residues aiming at adding high value to these agro-food by-products. We performed a first extraction step using supercritical CO2, followed by a second extraction step where different CO2 + ethanol mixtures (10–100% v/v) were tested. All experiments were carried out at 25 MPa and 50 °C. Extracts were characterized in terms of global yield, phenolic content and antioxidant activity using chemical (ORAC, HOSC, HORAC) and cell-based assays (CAA). We demonstrated that, although the pressurized 100% ethanol condition promoted the highest recovery of phenolic compounds (509 ± 8 mg GAE/100 g BE residues), the extract obtained with 40% ethanol presented the highest CAA (1.50 ± 0.24 µmol QE/g dw) and ORAC (285 ± 16 µmol TEAC/g dw), as well as HOSC and HORAC values, which correlated with its content of epicatechin and procyanidin B2. Noteworthy, this fraction inhibited free radical production in human neurospheroids derived from NT2 cells, a robust 3D cell model for neuroprotective testing.

Impact of Extraction Process in Non-Compliant ‘Bravo de Esmolfe’ Apples towards the Development of Natural Antioxidant Extracts

The ‘Bravo de Esmolfe’ apple (BE) is rich in antioxidants and represents one of the most important traditional cultivars in Portugal. A large amount of non-compliant BE, with no market value, it is generated every year. Thus, an effort to find value-added solutions is of utmost importance. For the first time, green extraction (microwave-assisted-extraction (MAE) and ultrasound-assisted-extraction (UAE)) were compared against conventional extraction (with (CET) and without temperature (CE)) to select the most efficient process to produce a natural antioxidant extract from non-compliant BE. The results showed that MAE and CET are good methodologies for developing a BE antioxidant extract. However, MAE is more sustainable than CET, requiring less time to reach high temperatures. The MAE-extract showed great antioxidant activity (14.80 ± 0.70 mg TE/g DE by ORAC, 3.92 ± 0.25 mg AAE/g DE by ABTS, and 5.11 ± 0.13 mg TE/g DE by DPPH). This extract revealed high amount of chlorogenic acid (0.48 ± 0.07 mg/g DE), (−)-epicatechin (0.30 ± 0.02 mg/g DE) and phloridzin (0.13 ± 0.01 mg/g DE). This study shows that non-compliant BE is a useful source of antioxidants, being a sustainable way for the recovery of value-added compounds from the rejected fruit in line with sustainable and circular bioeconomy principles.

Edible Coatings Enriched with Essential Oils on Apples Impair the Survival of Bacterial Pathogens through a Simulated Gastrointestinal System.

Edible coatings supplemented with essential oil components have been investigated to control spoilage microorganisms. In this study, the survival of Listeria monocytogenes and Salmonella enterica serovar Typhimurium on apples treated with edible coatings based on sodium alginate (2%) (ECs) and supplemented with essential oil components, namely eugenol (Eug) at 0.2% or in combination with 0.1% (v/v) of Eug and citral (Cit) at 0.15% was determined. Both bacterial pathogens were exposed on apples treated with ECs supplemented with Eug or Eug + Cit and challenged with gastrointestinal fluids and their survival was examined. Both pathogens were able to survive on the surface of ‘Bravo de Esmolfe’ apple. The use of ECs in fresh-cut fruits impaired the survival of both bacterial populations over 72 h at 4 °C. The exposure of the pathogens on apples with ECs supplemented with Eug and Cit and challenged with gastrointestinal fluids significantly reduced their survival. This study evidences that the use of alginate edible coating enriched with Eug or the combination of Eug and Cit can contribute to the safer consumption of minimally processed fruits.

Antioxidant and antimicrobial properties of dried Portuguese apple variety (Malus domestica Borkh. cv Bravo de Esmolfe)

Malus domestica Borkh apples are one of the most consumed fruits in the world, due to their sweetness and flavour. Herein, ‘Bravo de Esmolfe’ apple fruits were characterized regarding their nutritional value, chemical composition and bioactive properties. Besides nutrients, flavan-3-ols (i.e., epicatechin and B-type procyanidins) as also hydroxycinnamoyl-quinic acids and phloretin derivatives were identified in the samples. Extracts prepared from ‘Bravo de Esmolfe’ also proved to have antioxidant activity and antibacterial effects against Gram-positive bacteria, namely methicillin-susceptible Staphylococcus aureus (MSSA), methicillin-resistant Staphylococcus aureus (MRSA), Listeria monocytogenes and Enterococcus faecalis, and against the Gram-negative bacteria Escherichia coli, Escherichia coli (ESBL) (producing extended spectrum β-lactamases) and Morganella morganii. There is very little information about ‘Bravo de Esmolfe’ apple, so this study is important to inform consumers about an alternative source of nutritional and bioactive compounds.

Effect of a HPP pretreatment on thermal inactivation kinetics of polyphenoloxidase obtained from three apple cultivars

AbstractEnzymatic browning due to the action of polyphenoloxidase (PPO) is highly undesirable and efficient methodologies to avoid/reduce it are of great interest for food industry. The effect of a pressure pretreatment (100 MPa, 15 min, room temperature) on the activity of PPO extracts obtained from three apple cultivars (Bravo de Esmolfe [BE], Reineta [RN], and Golden delicious [GD]), and subsequent thermal inactivation kinetics was evaluated, as a way to more efficiently achieve thermal inactivation of PPO. The effect of pH on PPO activity was also assessed to define the value at which carry out the thermal inactivation of PPO. The enzymatic activity decreased in the order BE, RN, and GD. Two log‐linear ranges ([62.5–72.5] °C and [72.5–80.0] °C) of D‐value with temperature were found. The pressure pretreatment caused enhanced stability within the range of 62.5–67.5 °C, caused no changes at 70.0–72.5 °C, and decreased the stability at 75.0–80.0 °C (e.g., at 75 °C the D‐values for BE, GD, and RN ranged, respectively, from 25.6/27.3, 14.5/18.6, and 8.8/10.4, after/before the pressure pretreatment) and increased thermal sensitivity (decreased the z‐value), particularly in the lower temperature range studied (up to 72.5 °C).Practical applicationsKnowledge of PPO activity level and its thermal resistance for different cultivars is of interest to develop efficient and optimized enzymatic browning control by thermal treatments. Sequential combination of low intensity pressure treatments followed by thermal treatments can be an interesting approach to enhance enzyme inactivation. In this work was found that after a low intensity pressure pretreatment (100 MPa, 15 min), apple PPO temperature stability could be reduced, since a lower stability (lower D‐values) and increased sensitivity toward temperature (lower z‐value) was systematically found for PPO thermally inactivated at T > 72.5 °C. These findings are of interest for a more efficient PPO inactivation for enhanced browning control.

The effect of edible coatings on the nutritional quality of ‘Bravo de Esmolfe’ fresh-cut apple through shelf-life

The effect of edible coatings in combination with anti-browning agents on fresh-cut ‘Bravo de Esmolfe’ apple was studied. Four formulations of edible coatings were used: sodium alginate (AL) at 2% (w/v) with either eugenol (Eug) 0.1% (w/v) or Eug 0.1% + citral (Cit) 0.15% (w/v) and pectin (PE) 2% (w/v) with Eug 0.2% or Cit 0.15%. Three anti-browning agents were used: ascorbic and citric acids at 1% (w/v) and sodium chlorite at 0.05% (w/v). Fresh-cut apples were immersed into those solutions and then stored at 4 °C. On days 0, 2, 4, 6 and 8, samples were taken to perform physicochemical and biochemical analysis (browning index, firmness, weight loss, microbial growth, taste panels, total phenols, flavonoids, sugars content, antioxidant activity and ethylene production). The AL edible coatings performed better than the PE in reducing the browning index. Edible coatings improved the shelf-life of fresh-cut apple by reducing microbial spoilage without significantly affecting sensory and nutritional qualities. The anti-browning agents further increased this capacity, with ascorbic acid performing best. Based on general and sensory quality characteristics, fresh-cut apples appeared to be better preserved with AL 2% + Eug 0.1% plus dipping in ascorbic acid 0.1%.

Edible coatings enriched with essential oils for extending the shelf‐life of ‘Bravo de Esmolfe’ fresh‐cut apples

SummaryEdible coatings based on sodium alginate (AL) and pectin (PE) at 1% and 2%(w/v) enriched with eugenol (Eug) and citral (Cit) at minimum inhibitory concentrations (MIC) (0.10% and 0.15%) and double MIC were used to preserve the quality of fresh‐cut apples ‘Bravo de Esmolfe’. Samples were taken, through 14 day at 4 °C, for analysis of colour CIE(L*h°C*), firmness, °Brix, weight loss, antioxidant activity (TEAC), microbial growth and taste panels. With those quality characteristics, three groups were formed by the principal component and hierarchical cluster analysis, for each coating base (AL or PE). Based on, for each quality parameter measured, the mean closest value to the one at harvest for colour, higher value for firmness, °Brix and TEAC, and lower value for weight loss and microbial spoilage, the best group was selected for AL and PE. From each group, two edible coatings with the highest scores in overall acceptability were selected for fresh‐cut apples: AL2% + Eug 0.1%, AL2% + Cit 0.15% + Eug 0.1%, PE 2% + Cit 0.15% and PE 2% + Eug 0.2%.

Fungi Isolated from Traditional and Exotic Apple Varieties from Portugal and Patulin Production

The objective of our study was to examine the effects of cultivar type on developed fungi species and evaluate the potential for patulin production by fungi. In addition, patulin diffusion was also investigated. The experiments were carried out in traditional (Bravo de Esmolfe) and exotic apples (Golden, Starking, Fuji, Reineta Parda and Gala Galaxy) varieties from Portugal. High-performance liquid chromatography with solid phase extraction and UV detection (SPE-HPLC-UV) was validated and used to analyze patulin in the apple. The most prevalent fungal population was Penicillium spp and 27% of rotten fruits had patulin. Fungi of the genera Cladosporium spp., Alternaria spp., Fusarium spp. and Aspergillus spp. were also found even in apples without patulin production. The variety with the highest production of patulin was Bravo Esmolfe, however this variety showed the lowest prevalence of Penicillium spp. compared to other varieties of apples where was detected patulin.Patulin was not detected in any apples of Fuji and Gala varieties, despite having been identified fungi usually associated with the production of patulin. Thus, these two varieties are presented as the most suitable for the production of the apple based-foods.

Composition of pectic polysaccharides in a Portuguese apple (Malus domestica Borkh. cv Bravo de Esmolfe)

Malus domestica Borkh. cv Bravo de Esmolfe is a typical Portuguese apple cultivar classified as Protected Designation and Origin (PDO). It is a traditional product produced under strict conditions and labelled with a specific law protected designation. This cultivar presents quite good sweetness and flavor. The monosaccharide composition of the pectic polysaccharides from this traditional apple is herein reported for the first time. Based on the molar ratios obtained from the sugar composition, the presumable pectin structure could be inferred. The cell-wall polysaccharides present in the alcohol-insoluble residue (AIR) of unpeeled BE apple were sequentially fractionated. In addition, pectic material was also extracted by citric acid treatment prior to heat extraction at acidic pH. The water soluble pectin, imidazole soluble pectin and sodium carbonate soluble pectin account for 44, 16 and 40 % of the AIR, respectively. The pectic polysaccharides extracted in the presence of citric acid had lower galacturonic acid content and higher neutral sugars content. The homogalacturonan (HG) and less-substituted rhamnogalacturonan (RG) domains are extracted first. Pectin treated with citric acid has been shown to contain more substituted polymers, especially RG-I. In addition, the relatively higher Xylose/Galacturonic acid ratio found in the citric acid extract demonstrates that the xylogalacturonan (XG) domain presumably is present in the pectic material of the unpeeled BE apple.

Evaluation of cardiovascular protective effect of different apple varieties – Correlation of response with composition

Epidemiological evidence supports the concept that diets rich in fruits and vegetables promote health and attenuate or delay the onset of cardiovascular disease (CVD). In particular, a reduced risk of CVD has been associated with apple consumption, probably due to the cholesterol-lowering effect of the main bioactive compounds, namely fibre and polyphenols.In this work, the effect of diet supplementation with 20% of three Portuguese apple cultivars (Bravo de Esmolfe, Malápio Serra and Golden), containing distinct phenolic and fibre concentrations, on serum lipid profile and oxLDL of male Wistar rats fed a cholesterol-enriched diet (2%) was evaluated. After 30days, only Bravo de Esmolfe apple was able to decrease significantly serum levels of triglycerides, total and LDL cholesterol concentrations (reductions of 27.2%, 21.0% and 20.4%, respectively, in relation to the cholesterol-enriched diet group, P<0.05). The levels of oxLDL were also significantly improved with the consumption of this apple variety (reductions of 20.0% and 11.9%, in relation to the cholesterol-enriched diet group and control group, respectively, P>0.05) as well as with Malapio da Serra apple (reductions of 9.8% in relation to the cholesterol-enriched diet group, P<0.05). Correlation of the bioactive response with chemical composition showed that catechin, epicatechin, procyanidin B1 and β-carotene are the major phytocompounds responsible for the cholesterol lowering ability of apples. The antioxidant potential may have also contributed to this beneficial effect.

Metschnikowia andauensis as a new biocontrol agent of fruit postharvest diseases

Potential antagonists were isolated from the epiphytic flora associated with oranges and pome fruit. A total of 1465 microorganisms were tested in a preliminary screening against blue and green moulds on pome and citrus fruit, respectively. Among them, approximately 3% reduced incidence and severity by more than 50% and 4 microorganisms fulfilled the selection criteria of reduction in severity and incidence by 75%. The most effective was a yeast identified as Metschnikowia andauensis, strain NCYC 3728 (PBC-2), isolated from the surface of ‘Bravo de Esmolfe’ apple fruit cultivated in North Portugal. The biocontrol activity of M. andauensis PBC-2 was dependent on its applied concentration. At 5 × 10 6 cfu/mL incidence (% of infected wounds) and severity (lesion diameter) were reduced by 62 and 70%, respectively and at 1 × 10 7 cfu/mL, the greatest reduction was achieved, 90% of incidence and 95% of severity. The broad spectrum of action of M. andauensis PBC-2 was evaluated with effective control being achieved against Rhizopus stolonifer, Penicillium expansum and Botritys cinerea, on ‘Rocha’ pears and on different apple cultivars and against Penicillium digitatum and Penicillium italicum on mandarins and oranges. In semi-commercial trials in cold storage, the reduction of blue mould was 90%. Rapid colonization of fresh apple fruit wounds was observed during the first 24 h of cold storage, followed by a significant population increase during the first 15 days of storage and then the population remained stable until the end of storage.

Characterization of traditional and exotic apple varieties from Portugal. Part 1 – Nutritional, phytochemical and sensory evaluation

Phytochemical and nutritional characterization of traditional (Bravo de Esmolfe, Malápio Fino, Malápio da Serra, and Pêro Pipo) and exotic (Golden, Starking, Fuji, Reineta Parda and Gala Galaxy) apple varieties from Portugal were performed. Measurements were taken on 43 parameters including water, protein, sugars, acids, fibre, vitamins (C, A,B1, B2, B3, B5, B6, B9, β-carotene and α-tocopherol), minerals (K, P, Mg, Ca, S, Na, Si, B, Fe, Al, Cu, Mn, Zn, Ni, Mo, Cd) and polyphenols (total, catechin, epicatechin, chlorogenic acid, phloridzin, quercetin-3-glucoside, quercetin-3-rhamnoside, kaempferol-3-glucoside, procyanidins B1 and B2). Nutritional composition results showed that traditional apples had higher contents of fibre, protein, sugars, β-carotene, vitamin E, Mg and phenolic compounds. A comparison between unpeeled and peeled apples was also performed for the Bravo de Esmolfe variety and the unpeeled apples had higher amounts of fibre. Results from sensory evaluation of traditional apples performed by selected assessors and consumers showed there were differences among sample attributes such as sourness, juiciness and hardness, and two apple varieties were preferred (Bravo de Esmolfe and Pêro Pipo) for their odour, taste, hardness and juiciness.

Characterization of traditional and exotic apple varieties from Portugal. Part 2 – Antioxidant and antiproliferative activities

Apples are known to have many health-promoting activities, especially anticancer, antiradical and antioxidant effects. Most of these actions are believed to be due to their polyphenolic components which vary greatly between different varieties. In this work, four traditional Portuguese apple cultivars (Bravo de Esmolfe, Malápio Fino, Malápio da Serra and Pêro Pipo) and five exotic varieties (Golden, Starking, Fuji, Gala Galaxy and Reineta Parda) were evaluated in terms of their bioactivity using both cell-based and cell-free assays; 17 parameters were evaluated for each sample. Results obtained were submitted to principal component analysis (PCA) and it was possible to conclude that Malápio Fino and Bravo de Esmolfe apple varieties have the highest antioxidant effect and Reineta Parda variety is the best cultivar in promoting antiproliferative effect against human colon (HT29) and gastric (MKN45) cancer cells. Correlations of the data obtained showed that among phenolic compounds catechin, epicatechin and procyanidin B1 were the major contributors to the antioxidant activity of apples whereas procyanidins (B1 and B2), phloridzin and epicatechin played an important role against human cancer cell proliferation.

Establishment of the volatile profile of ‘Bravo de Esmolfe’ apple variety and identification of varietal markers

The volatile composition of ‘Bravo de Esmolfe’ (BE) apple was achieved by headspace-solid phase microextraction (HS-SPME) followed by gas chromatography–mass spectrometry (GC–qMS) analysis using fruits from two different rootstocks (PAJAM2 and MM106), different trees of each rootstock, and different sections of each tree (north and south). Fruits were harvested in the maturity state defined for this variety and then stored for four months at 4 °C. During this period, analyses were made monthly. α-Farnesene was the compound found in the volatile profile of BE apple with the largest GC area. A large number of esters were also detected. Rootstocks, trees, and tree sections did not have statistical significance on the volatile composition of BE apples. However, the volatile composition changed throughout the storage period. The principal component analysis (PCA) allowed distinguishing between the apples obtained immediately after harvest and those stored for 4 months. In the first case, the volatile composition was related to the occurrence of aldehydes, aromatic hydrocarbons, and phenols and, in the second case, to esters and terpenoids. Ocymene, cymene, α-bergamotene, geranyl acetone, nerolidol, and ethyl 3-(methylthio)-propionate were identified for the first time in apples. This peculiar profile allows to propose them as varietal markers of BE apple variety. However, as this methodology has only been applied to BE apple, the occurrence of these compounds in other cultivars can not be excluded.

Relações de produtividade, área folhear e alternância na macieira bravo de esmolfe: Yield efficiency, leaf area and alternate bearing indices of apple cv. bravo de esmolfe

The Bravo de Esmolfe apple tree is the most reputed and valued regional variety, but the available technical knowledge about it does not suffice. It must be deepened, especially on what concerns tools for management and control of one of this cultivar’s most negative characteristics, the strong tendency to alternate bearing. Therefore, the aim of this study was to identify some yield relations that don’t cause alternate bearing, when grafted onto the dwarfing rootstock EMLA9, which has been considered as one of the best for intensive cultivation. For this, thirty 8 year-old apple trees of similar bulk, with different yield levels during 2004, were selected. Leaves were collected in November 2004 and their area measured, and corresponding inflorescences were recorded in April 2005, thus achieving a yield prospective for that campaign. From these values, together with yield background of the selected apple trees, some parameters were calculated which made it possible to analyse their behaviour and yield regularity. The results obtained at this first approach suggest that yield intervals of around 8–11 g per leaf, which correspond to 20–30 apples per centimetre of trunk diameter, as well as to values of among 10–15 leaves per harvested fruit, ward off alternate bearing, provided pruning is done in time, achieving good balance between yield and growth.

USING SCANNING ELECTRON MICROSCOPY FOR QUALITY EVALUATION OF APPLES AFTER COLD STORAGE

Changes in the cuticle, epidermis and pulp of apple fruits were studied after cold storage using scanning electron microscopy (SEM). Also the firmness of the pulp, soluble solids content and juice pH were quantified. The study did use of 3 different apple cultivars ('Golden Delicious', 'Oregon Spur' and 'Bravo de Esmolfe') subjected to different pre-storage treatments (hot water treatments and calcium chloride solutions). The main objectives concern to: the identification of structural differences among varieties; some explanations for individual behaviour along the storage period; and the relationship between pre-storage treatments and structure and quality evolution of the fruits along the storage period. The thickness of cuticle and its waxes is quite different (less in 'Bravo de Esmolfe' apples). The extension of cracks in cuticle wax is higher with long term storage than at the initial phase of the storage in untreated fruits. Heat treatments and calcium application contribute to quality preservation of apples, particularly reducing the acidity loss. SEM will be a very interesting tool to complement quality studies and to accompany the fruit behaviour during its life time.