Fabio Rodrigo Thewes

Respiratory quotient: innovative method for monitoring ‘Royal Gala’ apple storage in a dynamic controlled atmosphere

Apples (Malus domestica, Borkh.) which are not stored at low temperature or in a properly controlled atmosphere (CA) may have a high metabolic rate during the postharvest stage resulting in losses in quality. The aim of this study was to evaluate the quality of ‘Royal Gala’ apple fruit stored in accordance with a new method of dynamic controlled atmosphere (DCA).The respiratory quotient (RQ) was monitored at two temperatures which were then compared using a commercially available technology based on chlorophyll fluorescence DCA (DCA-CF) and static CA. Ethylene production and respiration rates were lower in apples stored in DCA than in CA, as a result of lower 1-aminocyclopropane-1-carboxylate oxidase activity, especially in apples stored in DCA-RQ2. Flesh firmness of apples stored in DCA did not differ from those stored in CA. Apples stored at 1 °C had less flesh breakdown occurrence and a high percentage of healthy fruit. ‘Royal Gala’ stored at DCA-RQ2 had less flesh breakdown than apples stored in CA; however, the apples stored in DCA-CF did not differ from those stored in DCA-RQ2 and CA. Apples stored at the highest RQ value (6 and 4), especially at 0.5 °C, had low O2 injury occurrence after storage. However the increase in temperature to 1.0 °C, reduced the occurrence of this disorder. Therefore, storage in DCA-RQ2 at 1 °C or DCA-CF at 0.5 °C are the recommendations of preference for ensuring maintenance of quality in ‘Royal Gala’ apples after eight months of storage.

Tamanho de amostra para a estimação da média de caracteres de maçã

The aim of this research was to determine the sample size (number of fruits) needed to estimate the average of Royal Gala and Fuji apples characters, evaluated at harvest and postharvest, after a period in cold storage. In Royal Gala and Fuji apples were measured eight characters at harvest and 11 after could refrigeration. For each character in each cultivar, measured at harvest and after cold storage, was calculated the mean, variance, coefficient of variation, skewness, kurtosis and checked the normality and, then, was calculated the sample size. Larger sample sizes are needed to estimate the average of: ethylene production, ratio, respiration, weight and acidity. Smaller sample sizes are needed for the measurement of longitudinal diameter, pulp firmness, total soluble solids, transversal diameters (major and minor) and juice content. The sample size required to measure the characters of Royal Gala apples is lower than that required for Fuji apples. In Royal Gala and Fuji apples, 88 and 190 fruits, respectively, are sufficient for the measurement of characters, at harvest and after cold storage, with estimation error of 5% of the average.

Tamanho de amostra para a estimação da média de caracteres de pêssego na colheita e após o armazenamento refrigerado

The aim of this research was to determine the sample size needed to evaluate peach fruit characters at harvest and after cold storage. Fruits were collected from a commercial orchard. In the laboratory, split randomly, two samples of 120 fruits each, one sample assessed at harvest and one stored at -0.5°C for 30 days, and then for five additional days at 20°C. Eleven characters were measured on each fruit at harvest and twelve after cold storage, being the central tendency measures and dispersion calculated and normality checked. After, it was compared the average and the homogeneity of variance at harvest and after cold storage and calculated the sample size for each character. In peach, 169 fruits are needed to estimate the pulp firmness, 34 fruits to estimate the weight, acidity and ratio, 11 fruits to assess fruit juiciness and six fruits to estimate the others characters at harvest and after cold storage, with an estimation error of 5% on average.

Estresse inicial por baixo oxigênio seguido do armazenamento em atmosfera controlada de maçãs 'Royal Gala'

The aim of this work was to evaluate the application of initial low oxygen stress and 1-methylcyclopropene (1-MCP) on quality maintenance of Royal Gala apples, when stored in a controlled atmosphere (CA). In order to do this, a lot of 50 % of the fruit was treated with 1-MCP (625 ppb) and one half of these, together with half of the fruit which did not receive the application of 1-MCP, were subjected to low oxygen stress (0.3 kPa for seven days) before being stored for seven months at 0.5 °C under the following CA conditions: 1.2 kPa O 2 + 2.0 kPa CO 2 ; 1.0 kPa O 2 + 2.0 kPa CO 2 ; 0.8 kPa O 2 + 1.0 kPa CO 2 ; 0.6 kPa O 2 + 1.0 kPa CO 2 e 0.5 kPa O 2 + 1.0 kPa CO 2 . After storage, and following a further seven days at 20 °C, analyses of fruit quality were carried out. The results show that initial low oxygen stress is not effective in maintaining quality, beyond increasing the occurrence of physiological disorders and decay. There was no big difference in the efficiency of the CA conditions used in this study on the conservation of fruit quality. The application of 1-MCP did not improve quality maintenance in fruit stored under ultralow oxygen, as seen at the lowest partial pressures (<1.0 kPa) used in this work.

Atmosfera controlada para o armazenamento de goiaba cultivar ‘Paluma’

Guava is a highly perishable fruit. Controlled atmosphere (CA) storage techniques could extend its shelf life while maintaining the quality of fruit. The aim of this work was to determine the best CA conditions for the storage of ‘Paluma’ guava. The experiment consisted in a randomized block design with the follow treatments: [1] 20.9 kPa O 2 + 0.03 kPa CO 2 (CS - control); [2] 1.0 kPa O 2 + 2.0 kPa CO 2 ; [3] 2.0 kPa O 2 + 2.0 kPa CO 2 ; [4] 3.0 kPa O 2 + 2.0 kPa CO 2 ; and [5] 3.0 kPa O 2 + 4.0 kPa CO 2 . Fruit were stored at 8°C (±0.2) at a relative humidity of 95% (±2.0). After 28 days of storage the fruits were evaluated for their physicochemical characteristics. The best CA storage conditions for ‘Paluma’ guava is 1 and 2 kPa O 2 combined with 2 kPa CO 2 . These conditions reduced the degradation of the peel green color , loss of firmness and acidity, and keeps the flesh color more ef fectively, but the high occurrence of decay during self-life is the limiting factor of the storage period.

Aminoethoxyvinylglycine: isolated and combined with other growth regulators on quality of ‘Brookfield’ apples after storage

Growth regulators are used in the production of apples worldwide, especially to extend the harvest period and maintain postharvest quality. This study aimed to investigate the effects of applying aminoethoxyvinylglycine (AVG) in isolation as well as in combination with other growth regulators and postharvest techniques on the harvest quality and storage potential of ‘Brookfield’ apples (Malus domestica), a ‘Gala’ strain. Fruit receiving AVG only had the highest starch content and the highest titratable acidity at harvest. After 8 months of storage, the AVG + 1-MCP (1-methylcyclopropene) and AVG + ABS (ethylene absorption) conserved higher flesh firmness than to all the other treatments. Naphthaleneacetic acid (NAA) application induced ACC oxidase enzyme activity at harvest, but not after storage. AVG application, with or without the aid of another technique, did not decrease the red skin color of ‘Brookfield’ apples. Low mealiness and a high healthy fruit percentage was obtained when the fruits were submitted to pre-harvest AVG application combined with NAA, 1-MCP and ABS. Internal carbon dioxide had an inverse correlation with the quantity of healthy fruit and was directly correlated with mealiness.

Storage of yerba maté in controlled atmosphere

The aim of this study was to evaluate the effect of controlled atmosphere in the change of color, chlorophyll degradation and phenolic compounds concentration in yerba mate thickly ground (“cancheada”) and thinly milled (“socada”). Yerba mate samples from the towns of Arvorezinha (RS - Brazil) and Sao Mateus do Sul (PR - Brazil) were stored in four levels of oxygen (1, 3, 6 and 20.9kPa of O2) and four levels of carbon dioxide (0, 3, 6 and 18kPa of CO2) and then were analyzed, after nine months of storage. According to the results, the O2 partial pressure reduction decreased the loss of green coloration, kept a higher content of chlorophylls and of total phenolic compounds. In relation to the different levels of CO2, a response as remarkable as O2 was not observed. The yerba mate that was thickly ground (“cancheada”) presented a better storage potential than the one thinly milled (“socada”) in the storage with O2 and with CO2. The 1kPa of O2 condition kept the yerba mate greener and with a higher content of chlorophylls and of total phenolic compounds after nine months of storage. The CO2 partial pressure kept the yerba mate coloration greener and with a higher content of chlorophylls and of total phenolic compounds, regardless of the level used, in the mate from both cultivation areas.

Development of dispersive solvent extraction method to determine the chemical composition of apple peel wax

A method to extract apple peel wax was developed using the dispersive solvent extraction technique and applied to four apple cultivars (Royal Gala, Pink Lady®, Red Delicious, and Granny Smith). Different variables of the method were optimized, namely type and volume of extraction and dispersive solvents, ionic strength, and use of ultrasound. Extracts were evaluated as gravimetric yield of wax and composition as determined by gas chromatography. Optimized conditions provided yields higher than 95%. In a repeatability assay, the relative standard deviation for the extracted wax content was <3%. Thirty-one wax compounds were identified, among them fatty acids, hydrocarbons, sterols, and terpenes. Fatty acids were the major constituents in the analyzed extracts. N-alkane, nonacosane, and triterpene ursolic acid were also significant constituents. The method allows the determination of the total peel wax content and the different constituents of this fraction from distinct apple cultivars.

ETHANOL AND NITRIC OXIDE IN QUALITY MAINTENANCE OF ‘GALAXY’ APPLES STORED UNDER CONTROLLED ATMOSPHERE

O objetivo deste trabalho foi caracterizar e determinar o indice de qualidade e o ponto de colheita dos frutos de Eugenia cibrata. Os frutos foram colhidos aos 39; 41 e 43 dias apos a antese e selecionados pelo maior tamanho. Os frutos amadurecidos na planta, por ocasiao da completa abscisao, foram considerados padrao para determinar o indice de qualidade apos a colheita. As analises foram efetuadas no dia da colheita e aos dois dias de armazenamento sob temperatura de 26 ± 2oC e umidade relativa de 85 - 90%. Foram determinados firmeza, numero de sementes, diâmetro longitudinal e transversal, indice de formato, massa de sementes, da polpa e do fruto, acidez titulavel (AT), solidos soluveis (SS), acido ascorbico, ratio (SS/AT ) e rendimento de polpa. O delineamento experimental foi o inteiramente casualizado, em esquema de parcela subdividida no tempo, com tratamento adicional. O fruto da E. cibrata e uma baga arredondada com indice de formato de 0,98; massa de 24,28 g, cor verde no epicarpo e branca no endocarpo. O estadio de maturacao fisiologica deu-se a partir de 43 dias apos a abertura da flor (antese). Frutos selecionados dentre os de maiores tamanhos tambem atingiram estadio de maturacao fisiologica e qualidade semelhante aos frutos amadurecidos na planta. O indice de qualidade da E. cibrata, resultado da avaliacao do fruto maduro, constitui de pH em 2,88; solidos soluveis em 3,7 oBrix; acidez titulavel em 3,38% em acido citrico; 77,05 mg 100g-1 de acido ascorbico, relacao solidos soluveis/acidez titulavel (ratio) de 1,09 e rendimento de polpa em 72,01%.

Controlled atmosphere maintains native and cultivated yerba mate quality during shelf life after long-term storage

Yerba mate shows social and economic importance for the Southern Latin American countries due to its easy production and large market range. However, there is a problem to harvest the yerba mate at the correct period and to store it until processing and marketing. Thus, the aim of this paper was to evaluate the interaction among the storage in controlled atmosphere, effect of cultivation form and shelf life period on yerba mate quality after long-term controlled atmosphere storage. The experiment was conducted in a factorial arrangement (3 controlled atmosphere conditions × 2 cultivation forms × 4 weeks of shelf life). Native yerba mate, stored under controlled atmosphere, showed higher chlorophyll concentration as compared to the cultivated one. Carotenoid concentration increased up to the third week of shelf life and thereafter remained constant, if the yerba mate was stored under ambient conditions. Oxygen partial pressure lowering allows long-term yerba mate storage, keeping its quality during four shelf life weeks at 20 °C. Controlled atmosphere is an efficient technique for yerba mate quality keeping during long-term storage and shelf life, allowing the harvest of the raw material at the correct period and the maintenance of its quality until processing and marketing. The cultivation form has a significant effect on the storage and shelf life potential of yerba mate stored under controlled atmosphere.