Industrially processed vacuum-packed peeled Kennebec potatoes: process optimization, sensory evaluation, and consumer response.

UNLABELLED: To optimize the processing and storage of Kennebec potatoes for sale in peeled, vacuum-packed ready-to-cook form, we studied the effects of blanching, various anti-browning solutions, and storage temperature. Unblanched potatoes pretreated with a mixture of 1% ascorbic acid and 0.5% citric acid, and stored at 2 °C, were found to have a shelf life of at least 1 mo without browning. Potatoes so treated differed sensorially from fresh potatoes, but were well received by consumers. PRACTICAL APPLICATION: The process described here maintains the characteristics of fresh potato with all the amenities of a processed product.

Changes in sensory properties of Galician chorizo sausage preserved by freezing, oil-immersion and vacuum-packing.

Galician chorizo sausage, a dry-cured meat product from northwest Spain, was conserved by different methods with the aim of increasing its useful life. We studied changes in the sensory properties of this dry-cured meat product conserved by freezing, vacuum-packing and a traditional method involving immersion in sunflower oil. The reasons for the elimination of the samples conserved in sunflower oil at sampling 13 (week 23) was an increase in rancid flavor, acid flavor and external odor intensity. In sampling 18 (week 41) the samples conserved by vacuum-packing were eliminated because of increases in acid flavor, external and internal odor intensity, flavor intensity and after-taste persistence. In the frozen sausages the changes in sensory properties happened very slowly during storage.

Sensory characteristics of Galician chorizo sausage packed under vacuum and under modified atmospheres.

One of the most widely used methods for conservation of Galician chorizo sausage is vacuum packing. Recently, some manufacturers have begun to implement packaging under modified atmospheres. We compared the sensory characteristics, over about 7 months of storage, of chorizos packed under vacuum or under a modified atmosphere (100% CO(2), 100% N(2), or 50:50 CO(2)/N(2)). Most of the 29 variables considered differed significantly between samples packed under vacuum and samples packed under the modified atmospheres. Nineteen of the variables varied significantly over the storage period. Parallel studies of gas permeabilities confirmed that the aluminum-polyester-polyethylene laminate used for packing under modified atmospheres showed very low permeability to both CO(2) and N(2).

Physicochemical and sensory properties of Galician chorizo sausage preserved by refrigeration, freezing, oil-immersion, or vacuum-packing.

Galician chorizo sausage is a traditional cured meat product from northwest Spain. We monitored changes in the physicochemical and sensory properties of Galician chorizo sausage conserved by four different methods, namely refrigeration, freezing, immersion in sunflower oil, and vacuum-packing. Refrigeration was the least effective method tested, with rapid deterioration of sensory properties, and oxidative spoilage evident from week 4 onward. Oil immersion and vacuum-packing gave reasonable conservation of sensory properties (despite some masking of aromas by the oil). Freezing gave acceptable conservation of sensory properties, and by week 6 there was still no evidence of oxidative spoilage.

Simultaneous determination of organic acids and vitamin C in green beans by liquid chromatography.

A method is described for determining and quantitating organic acids (oxalic, malic, citric, and fumaric) and vitamin C by liquid chromatography with a UV-visible detector that allows simultaneous monitoring at 2 wavelengths. The method was applied to samples of green beans (Phaseolus vulgaris L.). Recoveries were 97.8% for oxalic acid, 98.9% for malic acid, 98.7% for citric acid, 99.2% for fumaric acid, and 98.5% for vitamin C. Method precisions (coefficients of variation) were 1.7% for oxalic acid, 0.8% for malic acid, 0.9% for citric acid, 1.5% for fumaric acid, and 1.2% for vitamin C. Measurement precisions (coefficients of variation) were 1.32% for oxalic acid, 0.33% for malic acid, 0.62% for citric acid, 1.01% for fumaric acid, and 0.39% for vitamin C. Limits of detection were 0.025 mg/mL for oxalic acid, 0.022 mg/mL for malic acid, 0.024 mg/mL for citric acid, 1.0 x 10(-4) mg/mL for fumaric acid, and 2.7 x 10(-4) mg/mL for vitamin C.

Determination of vitamin C and organic acids in various fruits by HPLC.

Liquid chromatographic methodology for determination of vitamin C and organic acids in different fruits (whortleberry, blackberry, red currant, black currant, raspberry, babaco, feijoa, kiwano, passion fruit, red and yellow tamarillos, medlar, and persimmon) cultivated in Galicia, Spain are developed. Both methods use a C18 column and an RP-18 precolumn for the stationary phase. High-performance-liquid-chromatographic-(HPLC-) grade water is brought to pH 2.2 with sulphuric acid for the mobile phase. The flow rate is 0.4 mL/min, and UV detection is at 254 nm for vitamin C and 214 nm for organic acids. Coefficients of variation of 1.84, 1.20, 1.00, and 2.60% are obtained for the vitamin C, quinic acid, malic acid and citric acid, respectively.