Effect of Ethylene, Free Fatty Acid, and Some Enzyme Systems on Chlorophyll Degradation

Chlorophyll degradation was studied in two varieties of spinach in the presence or absence of ethylene. In both varieties chlorophyll degraded during storage. Acceleration of degradation due to the presence of ethylene could not be demonstrated. Gradual disappearance did not coincide with activation of chlorophyllase, nor did it produce any new colored compounds. Catalase activity decreased during storage, while peroxidase activity increased. Addition of linoleic acid and various enzymes to model systems containing chlorophyll a accelerated degradation of chlorophyll. Rate of degradation was reduced by addition of antioxidants, catalase or superoxide dismutase suggesting involvement of both singlet oxygen and molecular oxygen in the bleaching process.     

Milk Proteins Affect Yield and Sensory Quality of Cooked Sausages

Sausages were produced with seven different mixtures with skim milk powder, sodium caseinate and whey protein (1.5, 3, 5%) according to a simplex-centroid design, where the proportion of each ingredient varied from 0 to 100%. Principal component analysis (PCA) identified that sausages with 1.5% milk protein were most similar in sensory quality to the controls and had minimum cooking loss. PCA was effective to reduce the number of attributes to five to describe the main variation among the 1.5% milk protein sausages. A mixture of 1:1 blend of skim milk powder and whey protein resulted in the product with lowest cooking loss.     

A Comparison of CIE (1976) L*a*b* Values Obtained from Two Different Instruments on Several Food Commodities

The relationships between CIE (1976) L*a*b* color parameters from a Hunter LabScan II Sphere Spectrocolorimeter and two Minolta Chroma Meters were evaluated. Jams, yoghurts with jam, salami-type dry sausages, raw cauliflowers, mashed and raw potatoes and various color standards were used as samples. The numerical values of the color parameters depended upon the instrument used. The relationships between the color parameters could be described by linear regressions which were specific for each type of food except for mashed potatoes and cauliflower. Best predictions of color parameters from one instrument to another were obtained with the most homogenious types of food.     

Dairy Ingredients effects on sausage sensory properties studied by principal component analysis

The effects of dairy ingredients (1, 3, 5%)–ordinary and high-viscosity sodium caseinate, skim-milk powder, whey protein or demineralized whey powder–on sensory properties and instrumental texture and color of sausages, were investigated. Sausages were formulated with 2 or 4% potato starch and cooked to a core temperature of 76 or 82°C. Principal component analysis (PCA) revealed three dominating factors for sensory properties; the first related to dairy ingredients and starch concentrations, the two others to type of dairy ingredients. Results were verified by analysis of variance (ANOVA). Results of sensory analysis were further verified by textural and color analysis using PCA and ANOVA, respectively.