Estimate of respiration rate and physicochemical changes of fresh-cut apples stored under different temperatures

In this study, the influence of storage temperature and passive modified packaging (PMP) on the respiration rate and physicochemical properties of fresh-cut Gala apples (Malus domestica B.) was investigated. The samples were packed in flexible multilayer bags and stored at 2 °C, 5 °C, and 7 °C for eleven days. Respiration rate as a function of CO2 and O2 concentrations was determined using gas chromatography. The inhibition parameters were estimated using a mathematical model based on Michaelis-Menten equation. The following physicochemical properties were evaluated: total soluble solids, pH, titratable acidity, and reducing sugars. At 2 °C, the maximum respiration rate was observed after 150 hours. At 5 °C and 7 °C the maximum respiration rates were observed after 100 and 50 hours of storage, respectively. The inhibition model results obtained showed a clear effect of CO2 on O2 consumption. The soluble solids decreased, although not significantly, during storage at the three temperatures studied. Reducing sugars and titratable acidity decreased during storage and the pH increased. These results indicate that the respiration rate influenced the physicochemical properties.

Quality of 'Delta Valencia' orange grown in semiarid climate and stored under refrigeration after coating with wax

The effects of carnauba-based wax on the quality of 'Delta Valencia' orange produced in Ceará state, Brazil, were studied. The fruits were coated with carnauba-based wax and refrigerated (7 ± 2 ºC and 85 ± 2% R.H.) for 28 days. The quality attribute parameters assessed were weight loss, peel color (brightness, hue angle, and chromaticity), peel moisture, pH, soluble solids (SS), titratable acidity (TA), SS/TA ratio, ascorbic acid, total soluble sugars, reducing sugars, yellow flavonoids, and polyphenols. The results showed that 'Delta Valencia' oranges grown in the dry climate of Ceará state has excellent quality. The coated fruits lost mass at a lower rate than the the control fruits. No significant loss of soluble solids, titratable acidity, pH, and SS/TA ratio was observed, while ascorbic acid, soluble sugars, reducing sugars, yellow flavonoids, and polyphenols increased during storage in both the coated and control fruits. Carnauba-based wax coated fruits showed no signal of dehydration keeping their shiny green peel up to the end of the storage. The use of coating was crucial for the maintenance of visual quality by reducing mass loss, as well as keeping peel moisture.

Physicochemical and microbiological quality of raspberries (Rubus idaeus) treated with different doses of gamma irradiation

This study was conducted to evaluate the physicochemical and microbiological characteristics of raspberries exposed to different radiation doses. The fruits were harvested in the city of Campestre, MG, packed in polyethylene bags, and transported to the Federal University of Lavras (UFLA), where they were separated into 4 lots. Irradiation was performed at the Center for Development of Nuclear Technology in Belo Horizonte, MG. The doses used were 0 (control), 0.5, 1.0, and 2.0 kGy. After irradiation, the fruits were transported back to UFLA and stored at 1 ºC and 95% relative humidity (RH) for 12 days. The physicochemical analyses for mass loss, total soluble solids, titratable acidity, pH, total soluble sugars, total soluble pectin, firmness, vitamin C content, total antioxidant activity, and total phenolic, and the microbiological assays (coliform at 35 and 45 ºC, psychrotrophic and filamentous fungi and yeasts) were performed after 0, 3, 6, 9, and 12 days of storage. Lower loss of mass and filamentous fungi and yeast count were observed in the irradiated fruits, and 2 kGy was determined as the most effective dose for microbial control, but this irradiation dose also resulted in increased loss of fruit firmness.

Effect of thinning on flower and fruit and of edible coatings on postharvest quality of jaboticaba fruit stored at low temperature

Jaboticaba is a Brazilian fruit, native to the Atlantic forest, which belongs to the Myrtaceae family. In this work we describe the effect of the thinning of "flower", "fruit" and "flower & fruit" compared to non-thinned fruit (control) and of edible coatings with respect on nutritional composition, overall acceptability and shelf-life of jaboticaba ‘Sabara’, grown in an irrigated commercial orchard. "Flower and fruit" thinning allows fruit with higher quality as diameter, volume and mass. Non-thinned fruit shows higher yield, however fruit have lower quality. As a result of the improving quality at harvest, the shelf life was twice (~8 days) for thinned fruit. The lack of change in concentration of soluble sugar and absence of formation of volatile compounds during storage indicate that there was no natural fermentation of the jaboticaba pulp after harvest. Treatments with wax and calcium did not improve the jaboticaba shelf life.

Chemical evaluation and effect of bagging new peach varieties introduced in southern Minas Gerais - Brazil

Brazilian peach production is insufficient for domestic supply. Aiming to increase production in the state of Minas Gerais, 16 new peach tree varieties were introduced in the Serra da Mantiqueira region and their fruit were analyzed for sugar, total phenol and total carotenoid contents by colorimetric methods, and for organic acid content by high-performance liquid chromatography. In addition, we examined the effect of fruit bagging on the levels of such constituents. To do so, the fruit of half the trees of each variety were bagged. The levels of sugars, phenols, carotenoids and organic acids are genotypic characteristics and significantly differed among varieties. Despite being a good form of fruit protection, providing better aspect and reducing the need for pesticides, bagging leads to lower contents of components such as sugars, phenols and organic acids in most varieties. However, it cannot be stated that this practice interferes with sensory characteristics. Knowledge of the chemical constituents of these new varieties allows determining those ideal for fresh consumption (e.g., "Maciel", "Diamante", "T. Beauty", "Ouromel 2" and "C.1056", among others) and those more suitable for industrial processing (e.g., "A. Gold", "C.1122" and "C.1050"), as well as those which serve both purposes.

Effect of treatment with adsorbent resin on the volatile profile and physicochemical characteristics of clarified cashew apple juice

Increased preference for healthy and functional foods could be an opportunity to increase the consumption of clarified cashew apple juice. Given its level of fructose, glucose, and vitamin C, it can be used as a base in blends. However, its characteristic odor can interfere with the acceptance of these formulations, especially by consumers who are not familiar with cashew aroma. The aim of this study was to evaluate the effect of treatment with macroporous resins (FPA54, FPX66, XAD761, and XAD4) on the volatile profile and physicochemical characteristics of clarified cashew apple juice. After the treatment with the resins, the volatile profile was evaluated using solid-phase microextraction (SPME) and gas chromatography/mass spectrometry (GC/MS). The physicochemical analyses performed were: pH, soluble solids (ºBrix), total titrable acidity, reducing sugars, and vitamin C. Gas chromatography analyses showed that XAD4 and FPX66 led to a reduction of the initial amount of volatile compounds to 14.05% and 15.72%, respectively. These two resins also did not affect the physicochemical characteristics of the clarified cashew apple juice.

Effect of postharvest temperature on the shelf life of gabiroba fruit (Campomanesia pubescens)

The objective of this study was to determine the optimal temperature for storing gabiroba fruit (Campomanesia pubescens) without affecting compounds' quality. The fruits were stored at different temperatures (0 ºC, 6 ºC, 12 ºC, and 20 ºC) and the effect on the pH, total titratable acidity, soluble solids, total sugars, vitamin C, and antioxidant components such as tannins and total phenolic compounds was evaluated. It was observed an increase in the pH and total titratable acidity during storage at all the temperatures tested. Gabiroba fruits were stored for 9 and 3 days at 12 ºC and 20 ºC, respectively, and under both temperatures they showed a reduction in tannins and an increase in vitamin C content. As gabirobas armazenadas a 0º and 6 ºC alcançaram maior tempo de armazenamento After 12 days of storage, the fruits stored at 6 ºC contained higher amounts of water soluble solids, sugars, and antioxidants. In general, for long term storage, it is suggested to store gabiroba fruits at 6 ºC. On the other hand, for short term storage, the temperature of 12 ºC would be the better to keep high levels of vitamin C and phenolic compounds.

Survival of Lactobacillus rhamnosus probiotic strains in peach jam during storage at different temperatures

The survival of six probiotic wild strains of Lactobacillus rhamnosus was compared with that of a type strain during 78 days of storage at 25 and 5 ºC in peach synthetic medium (PSM) and commercial peach jam (PJ). Changes in viable cell counts, pH values, sugar content, and colour parameters were monitored. All strains exhibited better performances in PJ than in PSM, showing count values higher than 7 Log cfu g-1 up to 78 days of storage at 5 ºC. Almost all wild strains remained above the critical value of 6 Log cfu g-1 in samples stored at 25 ºC up to 45 days, while the Lb. rhamnosus GG type strain, used as control, was not able to survive later than 15 days. In the synthetic medium used, the strains showed better survival in the samples incubated at 25 ºC, remaining viable above the critical level up to 45 days of storage, except for the strain H12. The probiotic cultures added to jam did not significantly change the colour parameters of the product; however the metabolism of lactobacilli did cause changes in the pH and in the composition of sugars.

Characterization and development of marolo (Annona crassiflora, Mart.)

The objectives of this study was the physical, chemical, and physiological characterization of marolo (Annona crassiflora, Mart.) during its development. The fruits were harvested 12 Km off Itumirim, Southern Minas Gerais, Brazil, at 20-d intervals from anthesis to fruit maturity. The first fruits were harvested within 60 days. The total development of the fruit took 140 days starting from anthesis. At 140 days after anthesis, the fruit reached its maximum size, with mass of 1.380g, transverse diameter of 13.0 cm, and longitudinal diameter of 11.5 cm. During its development, the fruit showed increase in mass and in traverse and longitudinal diameters. The changes during maturation and ripening, such as: pH reduction and starch degradation, pectic solubilization, and increase in total sugars, soluble solids (ºB), respiratory rate (CO2), titratable acidity, vitamin C, and β-caroteno were observed from the 120th day of marolo development. A decrease in ability to sequester free radicals was observed up the 120th day, followed by an increase. The volatile compounds identified at the end of the development included the esters group only.

Stability of frozen marolo pulp during storage

Marolo, also known as araticum or head-to-black, is a globular berry, a species native to the Brazilian savannah. The aim of this study was to evaluate the physical, chemical, and microbiological stability of frozen marolo pulp during 12 months of frozen storage. It was observed that the levels of ash (0.28-0.22%), protein (0.77-0.71%), lipids (1.75-1.73%), carbohydrates (12.1-10.15%), calorie (67.23-59.01 kcal), sucrose (2.50-1.29%), citric acid (435.63-197.5 µg.g-1), tartaric acid (4.38-1.88 µg.g-1) , acetic acid (470.38-279.25 µg.g-1), ascorbic acid (3.00-0.00 µg.g-1), total pectin (0.67-0.39%), pH (3.88-3.83), and b* chromaticity coordinates (24.85-20.53) decreased reduced during storage, whereas the levels of moisture (85.10-87.19%), color parameters (L* 58.89-62.62 and a* 5.37-7.86), reducing sugars (4.53-5.62%), total soluble sugars (7.1-7.36%), soluble solids (7.0-8.4 ºBrix), total acidity (0.9-1.0%), malic acid (514.13-781.25 µg.g-1), soluble pectin (0.16-0.24%), and antioxidant (6.85-37.35% of DPPH discoloration) increased over the one-year of storage period. According to the physical, chemical, and microbiological parameters assessed, the product can be stored for 12 months without loss of quality with addition of citric acid as a preservative.

Changes in the physicochemical and microbiological properties of frozen araça pulp during storage

Araça belongs to the Myrtaceae family and is popularly known as araçá-comum, araçá-azedo, or araçá-do-campo. Frozen fruit pulp is of great importance for the food industry, which can produce it at the time of harvest, store it, and use it according to the demand of the consumer market and/or as an ingredient in the formulation of products such as yogurt, candies, and ice creams among others. The aim of this study was to evaluate the physical, chemical, and microbiological stability of frozen araça pulp during 12 months of frozen storage. It was observed that the levels of moisture (90.55-88.75%), ash (0.34-0.26%) total soluble sugars (7.11-6.62%), sucrose (3.55-1.39%), soluble pectin (0.24-0.23%), total pectin (0.5-0.46%), pH (3.82-2.31%), organic acids (698.12-122.25 µg.g-1 citric acid), and phenolic compounds (6.22-0.00 mg GAE.100 g-1) decreased during storage, whereas the levels of protein (0.61-0.83%), lipids (0.14-0.38%), total carbohydrates (8.36-9.78%), calorific value (37.14-45.86 kcal.100 g-1), reducing sugars (3.51-5.21%), soluble solids (5.17-6.0%), total antioxidant capacity (6.89-35.13%), and color parameters (L*49.75-50.67; a*0.79-1.82 and b*22.5-25.19) increased over the one-year storage period. According to the chemical and microbiological parameters assessed, the product can be stored for 12 months without loss of quality with addition of citric acid as a preservative.

Study of the aging of fermented of yacon (Smallanthus sonchifolius) and sensory profile and acceptance

Yacon is considered a functional food due to its the fructooligosaccharide (FOS) content, however its perishability and low production volume is a problem. The aim of this study was to analyze the changes in aging during one year of storage and conduct sensory analysis of fermented of yacon. For one year total acidity, volatile acidity, free and total sulfur dioxide, reducing sugars, sucrose, phenols and FOS and its antioxidant power were studied. At the end of aging a sensory profile and acceptance panel was performed. The total and volatile acidity increased significantly (p < 0.05). A decrease in fructooligosaccharide was also observed, indicating that yeasts are probably capable of hydrolyzing the latter. The total sulfur dioxide decreased significantly, demonstrating its ability to act well against oxidation products. This product showed good antioxidant capacity and sensory profiles of considerable acceptance. Therefore it can be affirmed that the alcoholic fermentation of yacon can be a good alternative for the industrial sector and farmers in the region could be encouraged to use large-scale production.

Production of medium-chain-length polyhydroxyalkanoate by Pseudomonas oleovorans grown in sugary cassava extract supplemented with andiroba oil

Pseudomonas oleovorans were grown on sugary cassava extracts supplemented with andiroba oil for the synthesis of a mediumchain- length polyhydroxyalkanoate (PHA MCL). The concentration of total sugars in the extract was approximately: 40 g/L in culture 1, 15 g/L in cultures 2 and 3, and 10 g/L in culture 4. Supplementation with 1% andiroba oil and 0.2 g/L of (NH4)2HPO4 was performed 6.5 hours after growth in culture 3, and supplementation with the same amount of andiroba oil and 2.4 g/L of (NH4)2HPO4 was performed at the beginning of growth in culture 4. The synthesis resulted mainly in 3-hydroxy-decanoate and 3-hydroxy-dodecanoate units; 3-hydroxy-butyrate, 3-hydroxy-hexanoate; and 3-hydroxy-octanoate monomers were also produced but in smaller proportions. P. oleovorans significantly accumulated PHA MCL in the deceleration phase of growth with an oxygen limitation but with sufficient nitrogen concentration to maintain cell growth. The sugary cassava extract supplemented with andiroba oil proved to be a potential substrate for PHA MCL production.

Nutritional value and antioxidant capacity of "cocoa honey" (Theobroma cacao L.)

Cocoa honey is considered as the liquid portion of cocoa pulp that is released from the fruit soon after it is cut open and can be used before fermentation by simple extraction due to its nutritional characteristics. The objective of the present study is to determine the biochemical characteristics of a cocoa by-product, "cocoa honey" (CH), produced in the State of Bahia-Brazil. The biochemical characterization was conducted to determine reducing sugars, total sugars, vitamin C, total dietary fiber, flavonoids, and total antioxidant activity using an EC50. It was observed that cocoa honey can be considered a source of bioactive compounds, can be consumed in natura or processed, and used as an ingredient in the chocolate industry and in other food products. However, it is necessary to use complementary methods, such as HPLC, to quantify the phenolic compounds of this by-product.

Green and brown propolis: efficient natural biocides for the control of bacterial contamination of alcoholic fermentation of distilled beverage

This study aimed to evaluate the efficiency of natural biocides, brown and green propolis, for the control of bacterial contamination in the production of sugarcane spirit. The treatments consisted of brown and green propolis extracts, ampicillin, and a control and were assessed at the beginning and end of harvest season in ten fermentation cycles. In the microbiological analyses, the lactic acid bacteria were quantified in the inoculum before and after the treatment with biocides, and the viability of yeast cells during fermentation was evaluated. The levels of acids, glycerol, total residual reducing sugars, and ethanol were analyzed for the wine resulting from each fermentation cycle. A reduction in the number of bacterial contaminants in the inoculum in the treatments with the natural biocides was observed, but it did not affect the viability of yeast cells. The control of the contaminants led to the production of higher levels of ethanol and reduced acidity in the wine produced. The results of the use of brown and green propolis to control the growth microorganisms in the fermentation of sugarcane spirit can be of great importance for using alternative strategies to synthetic antibacterials in fermentation processes including other distilled beverage or spirits.