Effect of previous chilling storage on quality loss in frozen (–20 °C) sierra (Scomberomorus sierra) muscle packed with a low-density polyethylene film containing butylated hydroxytoluene

Rancidity development during frozen storage (–20 °C) of sierra fish (Scomberomorus sierra) was studied. Fillets were packed in low-density polyethylene films with and without butylated hydroxytoluene added (BHT-LDPE and LDPE respectively). Fillets stored with no package were used as control. Special attention was given to the effect of previous ice storage (0, 3, 6, 9 and 15 days) on the quality of the frozen fish. Physical (pH and texture) and chemical (peroxide value, PV and thiobarbituric acid index, TBA-i) analyses were carried out. Lipid oxidation increased with ice storage time in fish muscle without film packing, being greater than the film packed muscle (with and without antioxidant). An effect of previous ice storage time was observed on the frozen product (in all treatments). However, fish muscle with film packing containing antioxidant showed less lipid deterioration. Under the conditions applied in this study, the plastic films with antioxidant prevented the lipids oxidation during the cold handling of the sierra muscle.

Effects of polyethylene film wrap on cooler shrink and the microbial status of beef carcasses

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Shelf life extension of individually film-wrapped mangoes

Mangoes cv. Keitt were individually sealed in a heat-shrinkable polyolefin film (D-955) and a low-density polyethylene film (LDPE), stored for 0-5 weeks at 12°C and 17°C, and then ripened unwrapped at 22°C. Weight loss of packaged mangoes was significantly lower than that of the non-wrapped control. A sensory panel ranked the mangoes for overall eating quality and appearance. D-955 and LDPE film-sealed mangoes and control had shelf lives of 33, 15 and 7 days at 12°C and 17,10 and 7 days at 17°C, respectively.

Effect of plastic film mulch on the production of butterhead lettuce cultivars under protected cultivation

The study was performed in a greenhouse with the aim of evaluating the production of butterhead lettuce cultivars with and without plastic film mulch in the summer. The cultivars studied were 'Elisa', 'Lídia', 'Herman' and 'Luísa'. The experimental design was a split plot, in which the main plot was plastic film mulch (with or without black polyethylene film) and the subplots were the cultivars, with three repetitions. The seedlings were grown in Styrofoam trays of 288 cells and transplanted 25 days after seeding in a space of 25 × 25 cm. Harvests were carried out 45 days after transplanting and the following variables were determined: fresh and dry weights of the aerial part, number of leaves per plant, plant height and the longitudinal and transverse diameters of the plant. Significant differences were found only among the cultivars for the characteristics studied, with no cover × cultivar interaction. Fresh weight of the aerial part of 'Lídia' (270.9 g) was greater than that of 'Herman' (142.5 g), but did not differ from those of 'Luísa' (229.8 g) or 'Elisa' (204.8). The dry weight of the aerial part of 'Lídia' (12.4 g) differed statistically only with respect to that of 'Herman' (7.9 g). The cultivars 'Luísa' and 'Elisa' had an aerial part dry weight of 11.4 and 11.2 g, respectively. The number of leaves per plant of the cultivars 'Luísa' (45.1) and 'Elisa' (43.0) was higher than for 'Herman' (24.05), but did not differ from that of the cultivar 'Lídia' (39.5). The mean transverse and longitudinal diameters, as well as the mean height of the plants, showed that 'Lídia', 'Elisa' and 'Luísa' had the greatest values. The cultivars 'Lídia', 'Elisa' and 'Luísa' were the most productive and plastic film mulch had no effect on lettuce production under protected cultivation.

Efeitos da cobertura do solo com filme de polietileno azul no consumo de água da cultura da alface cultivada em estufa

The covering of the soil is an agricultural practice that intends to control the harmful herbs, to reduce the losses of water by evaporation of the soil, and to facilitate the harvest and the commercialization, once the product is cleaner and healthier. However, when the soil is covered important microclimatic parameters are also altered, and consequently the germination of seeds, the growth of roots, the absorption of water and nutrients, the metabolic activity of the plants and the carbohydrates storage. The current trial intended to evaluate the effect of soil covering with blue colored film on consumptive water-use in a lettuce crop (Lactuca sativa, L.). The experiment was carried out in a plastic greenhouse in Araras - São Paulo State, Brazil from March 3rd, 2001 to May 5th, 2001. The consumptive water-use was measured through two weighing lysimeter installed inside the greenhouse. Crop spacing was 0.25 m x 0.25 m and the color of the film above soil was blue. Leaf area index (IAF), was measured six times (7; 14; 21; 28; 35; 40 days after transplant) and the water-use efficiency (EU) was measured at the end. The experimental design was subdivided portions with two treatments, bare soil and covered soil. The average consumptive water-use was 4.17 mm day-1 to the bare soil treatment and 3.11 mm day-1 to the covered soil treatment. The final leaf area index was 25.23 to the bare soil treatment and 24.39 to the covered soil treatment, and there was no statistical difference between then.

Ambientes de cultivo, recipientes e substratos na produção de biomassa foliar e radicular em mudas de maracujazeiro amarelo em Aquidauana - MS

The objective of the work was to evaluate the effects of environment, recipients, and substrate compositions in passion fruit (Passiflora edulis Sims f. flavicarpa Deg.) seedlings biomass production in Pantanal region from September to November of 2006. Experimental trials were conducted in four protected environments, in two types of containers and three different substrate compositions. The environments were: A1 (greenhouse covered with low-density, 150-microns-thick polyethylene film), A2 (monofilament black screened with mesh for 50% of shade), A3 (aluminized screened with mesh for 50% of shade) and A4 (environment covered with straw of native coconut palm); the recipients were: polyethylene bags (R1) (15 x 25 cm) and polystyrene trays (R2) (with 72 cells). There substrates were: S1 (soil + organic compost + vermiculite, 1:1: 1 v/v), S2 (soil + organic compost + sawdust, 1:1: 1 v/v) and S3 (soil + organic compost + vermiculite + sawdust, 1:1: 1/2: 1/2 v/v). The experimental design was completely randomized statistical analysis in split-split-plot, with fifteen replications. The treatments in the plot were environments, in the subplots were pots, and subsubplots were substrates (4 x 2 x 3 = 24 treatments). Fresh and dry mass of aerial and root system parts were evaluated. Environments with screen showed better results for seedlings of yellow passion fruit biomass in polyethylene bags. Polyethylene bags promoted higher biomasses. The substrate with vermiculite showed better results for both types of containers. The substrate with a higher percentage of sawdust showed the worst result.

Protected environments and substrates for production of genipap seedlings

Genipap (Genipa americana L., Rubiaceae ) is a native Brazilian species and can be used in the recovery of degraded forest areas or for food supply. In order for the species to reach its potential, production of high quality seedlings is essential. The objective of this study was to evaluate genipap seedlings in protected environments and different substrates. The environments tested were: (1) a greenhouse with polyethylene film in the top, with aluminized screen (Aliminet®) of 50%-shading under this film, and lateral sides covered with 50%-shading nylon net (Sombrite®), (2) a shaded hut, all sides covered with 50%-shading nylon net (Sombrite®), and (3) a nursery shelter, with all lateral sides uncovered and the roof covered with leaves of buriti (Mauritia flexuosa). In these environments the following substrates were tested: 50% cattle manure + 50% cassava foliage, 50% cattle manure + 50% Vida Verde®, 50% cattle manure + 50% vermiculite, and 25% cattle manure + 25% vermiculite + 25% of cassava foliage + 25% Vida Verde®. Because there was no repetition of the growth environment, the effect of environment was examined using statistical procedures for analysis of combined experiments. Within environments a completely randomized design was used with five replications. All substrates are suitable for the formation of genipap seedlings, where the recommended substrates are: 50% cattle manure + 50% cassava foliage and 50% cattle manure + 50% Vida Verde® for the greenhouse and the substrates composed of 50% cattle manure + 50% vermiculite and 25% cattle manure + 25% cassava foliage + 25% Vida Verde®+ 25% vermiculite for the shaded hut. The buriti shelter is not recommended for production of genipap seedlings.

Substrate with Organosuper® for cucumber seedlings formation in protected environments and polystyrene trays

Culture environments, trays and doses of organic compost were evaluated in the formation of cucumber seedlings (Cucumis sativus L.). Five environmental conditions were tested: (A1) a greenhouse with height of 2.5 m, covered with polyethylene film, (A2) nursery with height of 2.5 m, monofilament fabric, 50% shading, (A3) nursery with height of 2.5 m, heat-reflective screen, 50% shading, (A4) nursery with a height of 1.8 m, covered with coconut tree straw and (A5) greenhouse with height of 4.0 m, covered with polyethylene film, with zenith opening and thermo-reflective cloth under the plastic. Trays of 72 (R1) and 128 (R2) cells were filled with 93% soil and 7% organic compound (S1), 86% soil and 14% organic compound (S2) and 79% soil and 21% organic compound (S3). It was used a randomized design in split-split-plot scheme, with five replicates (environments x trays x substrates). The greenhouses provide the best environments for the formation of cucumber seedlings. A tray of 72 cells is the best container, promoting more vigorous seedlings in substrate with soil and 7 or 14% organic compound.

Soursop seedlings: biomasses and biometric relations in different farming environments and substrates – Part II

ABSTRACT The quality of seedling is critical to obtain vigorous plants in the field. The present study aimed to assess biomasses and biometric relations of soursop seedlings. We used different substrates in protected environments. The experiment was performed at the Universidade Estadual do Mato Grosso do Sul (UFMS) (State University of Mato Grosso do Sul). Five farming environments were developed in greenhouses: one covered with low-density polyethylene film (LDPE), another with with polyethylene and heat-reflective cloth under film under 50% shading in aluminized color, monofilament cloth under 50% shading in black, thermo-reflective cloth under 50% shading in aluminized color, and an environment covered with bacuri coconut straw. Substrates were made of manure, humus, cassava branches and vermiculite at different proportions. Each of them varying from 25%, 33.3%, 50% and 75% in mixture combination. Each environment was considered an experiment. A completely randomized design was adopted and later a joint analysis of them. Agricultural greenhouse covered with LDPE and thermo-reflective cloths under 50% of shading, proportionated seedlings with greater biomass. Substrates containing manure are the most suitable for soursop seedlings. High percentages of earthworm humus produce low quality soursop seedlings. Soursop seedlings had a Dickson’s quality index around 0.335. The greenhouse covered only with LDPE film did not produce high quality seedlings.

Postharvest technologies for mangosteen (Garcinia mangostana L.) conservation

The application of technologies to extend the postharvest life of mangosteen fruit was studied and compared to storage at 25 °C/70-75%R.H (25 °C control treatment). The fruits were packed in expanded polystyrene (EPS) trays (5 fruits/tray). Five treatments were carried out at 13 °C/ 90-95% RH: application of carnauba wax coating, lecithin + CMC (carboxymethyl cellulose) coating, 50 µm LDPE (low density polyethylene) film coating, 13 µm PVC (Polyvinyl chloride), and non-coated sample (13 °C control treatment). Physicochemical analyses were performed twice a week. A statistical design was completely randomized with 8 repetitions for each treatment plus the control treatment. The results were submitted to variance analysis, and the averages compared by the Tukey test at 5% probability. Among the quality parameters analyzed, more significant differences were observed for weight loss, texture, and peel moisture content. The results showed that the maximum storage period for mangosteen at 25 °C is two weeks; while storage at13 °C can guarantee the conservation of this fruit for 25 days. Therefore, the treatment at 13 °C/90-95% RH without the use of coatings and films was more effective and economical.

Physicochemical and microbiological characteristics of minimally processed 'Champagne' oranges (Citrus reticulata × Citrus sinensis) in different packgings

The objective of this study was to investigate the influence of the level of minimal processing and modified atmosphere on the quality of 'Champagne' orange stored under refrigeration. The fruits were subjected to the following processing: a) whole fruit without flavedo; b) whole fruit without flavedo and albedo; and c) segmented into wedges and packed as follows: uncoated packaging (control); polyethylene film; PVC film; gelatin-based edible films (3%); and polyesthyrene translucent plastic container with a lid. The minimally processed oranges were stored at 5 ± 1°C for 8 days and were subjected to physicochemical and microbiological analyses every two days. Greater weight loss occurred in fruits without flavedo and segmented, uncoated, and coated with the edible gelatin film During storage, there was a slight increase in Total Soluble Solids (TSS) for the treatments with greater weight loss and reduction in acidity and ascorbic acid, regardless of the packaging type. The microbial counts did not exceed the acceptable limits in the treatments; however, higher counts were observed at the end of storage. The minimally processed fruit packed in lidded polystyrene containers and polyethylene and PVC films kept their overall fresh visual appearance with a few physicochemical and microbiological changes up to the 8th day of storage.

Modified atmosphere efficiency in the quality maintenance of Eva apples

Modified atmosphere is a method of food preservation that provides increased lifetime, decreases deterioration losses, and facilitates marketing. The objective of this study was to evaluate the efficiency of different plastic films in modifying the atmosphere around Eva apples to assure quality maintenance during postharvest storage. The fruits were cleaned and separated into three treatment groups: polypropylene, low density polyethylene, and high density polyethylene packing with a total of 5 fruits per package for each evaluation period. A group of control apples was not submitted to atmospheric modification. After the treatment, all fruits were stored at 0.5±0.5°C (cold storage) for up to 225 days. The analyses were performed at 45, 135, and 225 days after cold storage. Respiration, ethylene production, firmness, mass loss, total pectin, soluble pectin, soluble solids, total acidity, and epidermis background color of each treatment group were evaluated. The high density polyethylene film treatment did not show a decrease in ethylene production during storage and allowed the fruits to maintain a greater firmness and smaller percentage of mass loss during the study period. Moreover, the storage of the Eva apple cultivar under modified atmosphere allowed the preservation of quality for up to seven months.

Quality changes during frozen storage of blue shrimp (Litopenaeus stylirostris) with antioxidant, α-tocopherol, under different conditions

Fresh blue shrimp (Litopenaeus stylirostris) muscle was stored with antioxidants under different conditions: ANTIOX 2%, packed in bilayer film of polyamide-low density polyethylene film (PA-LDPE) with 2% α-tocopherol; ANTIOX 4%, packed in PA-LDPE film with 4% α-tocopherol; and ANTIOX-GLAZED, samples stored glazed with 2% α-tocopherol. Shrimps packed in PA-LDPE without α-tocopherol were used as CONTROL. All samples were stored at –20 °C for 120 days. As compared to the CONTROL, the shrimp stored with the antioxidant showed lower lipid oxidation (0.10-0.14 vs 1.58 mgMA/kg of muscle), lost less firmness and astaxanthin content. ANTIOX 2% and ANTIOX-GLAZED showed the lowest concentrations of formaldehyde (0.081-0.083 μM/g). There were no significant differences in color and sensory properties, but differences in the integrity of the muscle fibers were observed. The treatments with α-tocopherol maintained the shrimp muscle quality during frozen storage. However, no significant differences were found between these treatments.