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Prior to detailed quality and physiology evaluations, different immersion solutions (SIs) were analysed by means of a nontrained sensory panel. Each SI (calcium chloride, pectin, potassium sorbate, garlic extract and citric acid) was analysed at three concentrations. Based on at least 70% acceptance, the best mixed SI (P<0.05) was determined to be 2 g/L citric acid, 1 g/L calcium chloride and 250 g/L garlic extract (SI). The control treatment was washed only with 0.05 g/L active chlorine. Treated lettuce was stored at 5°C in darkness in sealed polypropylene bags, for 9 days. Some senescence indicators (weight loss, colour), certain enzymes related to colour (chlorophyllase and polyphenoloxidase), and a nutrient (ascorbic acid), were measured during storage. SI showed a positive effect on shelf-life of minimally processed lettuce, controlling enzymatic browning, chlorophyllase activity and weight loss. The microorganisms growth was not significantly controlled, but the fact that the organoleptic results of SI-treated lettuce showed about 80% acceptability during 9 days of storage, suggests that some slight modifications on SI could be the basis of a promising formula for minimally processed lettuce. [Copyright &y& Elsevier]

There is a need to increase vessel loads for high-pressure batch processes such as supercritical fluid extraction of solid substrates, but a precompacting treatment such as pelletization may negatively affect mass transfer rates. This work was aimed to quantify the effect of the microstructure of Jalapeño pepper pellets on the extraction rate and yield of oleoresins when using supercritical CO2 at 40 °C and 320 bar as the solvent, so as to contribute with basic information that will help optimize pelletization treatments for solid substrates. Four types of substrates were obtained by considering 2 initial particle sizes and 2 initial moisture levels before pelletization, and the inner porosity and tortuosity of the resulting pellets were estimated. The internal mass transfer was favored in pellets showing a better distribution and connectedness of pores, and the extraction rate and yield improved when using pellets from flakes instead of milled flakes, with initial sample moisture exhibiting a more limited effect. A reduction in the particle size of the pellets improved mass transfer but caused a reduction in packing density, and these 2 factors had opposite effects on the "volumetric yield" of the process (mass of recovered solute per unit time and per unit volume of extraction vessel), which was also affected by prepelletizing sample conditioning. [ABSTRACT FROM AUTHOR]

Abstract: The effect of murta (Ugni molinae Turcz) leaves extract on water vapor permeability (WVP) and gas permeability (GP) of carboxymethylcellulose (CMC)-based films was studied. Two ecotypes of murta leaves “Soloyo Grande” (SG) and “Soloyo Chico” (SC), were analyzed for their composition (HPLC-MS) and SC extract revealed a higher concentration of flavonols than the SG extract. The film forming solution was prepared with 2g of CMC, 0.4ml of glycerol and 0.5ml of sunflower oil in 100ml of water (Control), 50ml of water and 50ml of each exctract (SC50 or SG50) and 100ml of each extract (SC 100 or SG 100). The addition of murta leaves extract modified the WVP and GP of the films. The WVP decreased significantly (P⩽0.05) with the incorporation of SG extract in the film but not with the SC extract (P>0.05). The CO2 and O2 permeability of the films were influenced by the kind and concentration of murta leaves extract used. The CO2 permeability, with SG extract was higher than without extract (P⩽0.05) and with SC extract was not modified. The O2 permeability with murta leaves extract were lower than without extract. Therefore, it is possible to consider that films with SC acts only as barrier to the oxygen, but with SG the water vapor and gas barrier properties were modified, being more permeable to the CO2 and acting as barrier to O2 and water vapor. [Copyright &y& Elsevier]

Sugar snap peas (Pisum sativum L.) are edible-podded peas that, unlike snow (Chinese) peas, have thick pod walls. They are the result of the combination of at least six recessive genes controlling pod and grain traits, and two others are being incorporated in modern cultivar. Sugar snap peas may be consumed fresh or frozen, and are highly appreciated in the United States and other countries. Six genotypes from the USA were evaluated at two locations in La Araucania Region in southern Chile in 2004 and 2005. Most sugar snap varieties showed yields similar to a freezable cultivar used as a check. Yield differences among sugar snap varieties were small and inconsistent; however, cv. Sweet Ann performed relatively well and showed the best freezing quality. Over 15 t ha-1 of pods were obtained under favorable conditions, suggesting that yields around 10 t ha-1 are quite achievable commercially. All varieties presented, at variable levels, suture on both dorsal and ventral sides of the pods. A mild frost (-2 °C), harmless to the plant, may also deteriorate the appearance of the pods. Sugar snap peas are a delicate produce and, if well managed, can be a sound option to diversify Chilean horticultural offer. [ABSTRACT FROM AUTHOR]