Search Results
Three independent studies were conducted in Chile, Spain and Uruguay to assess the effects of the addition of enzymes on the shelf life of brown pan bread.Four batches of brown bread were prepared in each country: a control batch with no added enzymes, a second batch with amylase, a third batch with xylanase and a fourth batch with a 1:1 mixture of amylase and xylanase. Three sensory texture parameters were evaluated (softness, size of the soft area and cohesiveness) and a consumer study was conducted to determine the acceptability of the samples. In each country, the doses of each enzyme and enzyme mixtures (1:1) added to doughs have to be adapted to obtain good dough handling characteristics and minimise adhesiveness and stickiness of the corresponding flour in the traditional formulation.In all three countries the addition of the enzyme mixture gave the best results, achieving a longer shelf life, while the addition of xylanase accelerated bread staling.
Reliable product characteristics are needed for the prediction of shelf life by mathematical models in the post-harvest sector. Exact knowledge of the nature of changes during ripening and storage in refrigerated storage is essential. Authors investigated physical, chemical and biological changes of field-grown, autumn-harvested food grade potato (cultivar Kondor) as a function of temperature and storage time and the market quality was determined by visual assessment. Most of the investigations were preceded by sampling and methodological examinations. The most appropriate characteristics for the predictive modelling were: water soluble solids content, total starch content, weight loss during storage, marketability of the product (visually assessed) and texture parameters: acoustic firmness factor and bio-yield (by Instron Universal Testing Machine). Components of complex impedance, except for some cases, would be unreliable factors in model creation.
In the research area of healthier meat products a possible trend is to replace high energy density fat in formulations with substances providing less energy than fat. The aim of the producers is to obtain a product having maximum yield with similar or same organoleptic properties and structure like well-known full-fat analogues. Properties of high fat products can be restored with the use of different fat substitutes, non-meat protein, and/or hydrocolloids or starch, owing to their stabilization abilities, fat coating, and water binding, respectively. The review is aimed to summarize the effect of different fat substitutes on the processing quality, textural characteristics, and sensory properties of comminuted meat products with low lipid content.
The n-3 fatty acids advantageously affect human health. Thus, partial substitution of pig backfat with soybean- or flaxseed oils in “Párizsi” (lyoner), with the aim to increase its n-3 fatty acid (FA) content, resulted improved FA profile (n-6/n-3 ratio). Relatively high (9% flaxseed oil) substitution decreased this ratio to the optimum (∼4). This modified FA profile was preserved during 32 storage days. Oil addition influenced fresh surface colour: lightness (L*) increased, redness (a*) decreased in parallel with the increasing oil addition, while only soybean oil increased yellowness (b*). Storage altered the colour slightly. The texture was not systematically altered by oil substitution, while during storage in a vapour permeable casing hardness increased. Considering organoleptic properties, soybean oil improved the extent of spiciness, while the general consumer acceptance was the most favourable (within complemented samples) by 3% flaxseed oil. Increasing vegetable oil levels intensified the taste of spice mixture.
The purpose of this study was to evaluate the effect of rosemary essential oil (250–1000 ppm) or its leaves (0.5–2%) on the quality of turkey sausage. The addition of essential oil had no significant effect on the sausage texture and colour parameters. A high rosemary leaves level resulted in an increase in sausage hardness and chewiness and a decrease in lightness (L*) with respect to the control sausage. Sensory evaluation indicated that rosemary essential oil and its leaves increased the taste and the aroma scores of turkey sausage depending on the concentration. The obtained results also showed that rosemary leaves (0.5%) were more effective than essential oil in reducing total plate counts, TBARS, K232, and K270 values during chill storage, in comparison with the control product. This will contribute to reducing the use of chemical additives, which are badly perceived by consumers, while increasing the sensory properties of such products.
Water content of dry sausages may decrease due to improper ripening and storage as well. As a consequence, an outer crust appears on the surface of the products. The aim of the industry is either to eliminate the presence of outer crust, or decrease its occurrence. The thickness of outer crust can be estimated by non-destructive ultrasound technique. As the propagation time and attenuation of ultrasonic waves vary in the materials with different water content, the thickness of outer crust and the normal texture, respectively, can be estimated on the basis of these characteristics. The propagation and attenuation values are typical for the given layers. Thus, by measuring total attenuation and total width of the product, the thickness of outer crust can be calculated by means of the velocity and attenuation coefficients of ultrasonic waves. Results of this non-destructive measurement may support the proper adjustment of ripening and storage parameters such as temperature and humidity.
The objectives of the paper were to show that the evaporation intensity of water can be increased by the application of appropriate textile materials. The purpose was to determine the dependence of the evaporation intensity on the textile characteristics and the influence weather conditions on the evaporation intensity of different textiles. Five different textile strips of different widths and of single- and multi-layer were tested in definite experimental pots under open air conditions. The results of the experiments showed the total evaporation surface of the textiles depended on the texture material and the capillary volume of the textiles and the capillary volume had a limit at approximately V c = 1000–1200 cm3/m2. Another important result was that the relative air humidity is a main factor of the weather conditions that has principal influence on the evaporation intensity. However, the other parameters — such as temperature, solar radiation and wind speed — have only a secondary effect on the evaporation intensity of textiles.
Direct sowing (DS), row direct sowing (RDS), and the transplanting method (TM) were investigated for two onion cultivars, Azar-Shahr (red skin onion) and Horand (yellow-brown skin onion) during 1999, at Khalat-Pooshan Research Station, Tabriz University. Analysis of variance for the measured traits indicated that except for the percentage of class II onions, other traits were significantly influenced by the sowing methods. TM had higher values of total yield, marketable yield, percentage of class I and III, bulb weight, homogeneity (HOM) of bulb weight, bulb diameter, HOM of bulb diameter, bulb length, HOM of bulb length, bulb diameter at the neck and base, number of centres, and percentage of bulbs containing multiple centres than the other methods. The cultivars differed significantly only for bulb weight, HOM of bulb weight, and postharvest longevity characteristics. The data suggest that TM could be an effective method in onion production areas without causing a change in soil texture. RDS was also a better method than DS in terms of marketable yield, and homogeneity of bulb weight.
A study was conducted to develop nutritious unleavened bread (chapati) using partially defatted salt treated soy dhal, wheat and rice flour. Different salt treatments viz. sodium carbonate, sodium bicarbonate, sodium chloride and sodium tripolyphosphate were given which significantly (P<0.05) reduced the cooking time of soybean. The organoleptic evaluation of chapatis was conducted by scoring on a 9-point hedonic scale for various sensory parameters, i.e. colour, appearance, flavour, texture, taste and overall acceptability, which indicated that the developed chapati was acceptable to human palate. The protein and total soluble sugar contents of the developed chapati were significantly (P<0.05) higher than those of the unprocessed control. However, fat, ash and crude fiber contents varied nonsignificantly. Processing treatments, i.e. mixing and roasting involved in chapati making reduced the phytic acid (19.1%) and polyphenols (52.92%) contents significantly (P<0.05) over the unprocessed composite flour. As a result, in vitro protein and starch digestibility of chapati also improved significantly to the extent of 6.89 and 26.6 percent, respectively.
Lactic acid fermentation of carrot as a method of preservation using different lactic acid bacteria, viz. Lactobacillus plantarum, Pediococcus cerevisiae and Streptococcus lactis subsp. diacetylactis as such and in sequence at different temperatures and with varying salt content (2, 2.5 and 3%) were employed in the fermentation of carrot. The differences in fermentation behaviour of different microorganisms were quite contrasting at 26 °C, but the sequential culture started deviating from the very first day and acidity increased up to 6 days. A temperature of 26 °C and salt concentration of 2.5% were the best for lactic acid bacteria (LAB) fermentation of Asiatic carrot as highest acidity (1.40% lactic acid), low pH and low reducing sugars were achieved in sequential fermentation. The LAB count of 7.8×10 8 CFU ml −1 was also higher at these concentrations coupled with higher sensory scores of the products. Among the fermentation types tried, sequential culture fermentation of the vegetables produced the product with higher acidity, low pH and reducing sugars. The sequential culture fermentation imparted the fermented products better flavour, texture and taste than other products fermented naturally or with lactic cultures of Pediococcus cerevisiae, Lactobacillus plantarum and Streptococcus lactis in single separate fermentation. Based on the overall and sensory quality evaluation, the fermented carrot product prepared with sequential culture was the best followed by the product prepared using natural microflora.
