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micro-topography of cutting surface, DMC 2005, Development of Metal Cutting , Kosice, Slovakia, 12–13 September 2005, pp. H 1–4. ISO 4287/1-1997: Geometrical Product Specifications (GPS) — Surface texture: Profile method
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.
The textural properties and hydration capacity of legumes in general and of beans in particular is a subject about which much research has been done. However, at present there is still no practical answer to the “Hard to Shell” and “Hard to Cook” effects. The present investigation studies 14 varieties of recently picked beans that were grown in Mexico. The beans were classified by size using K-means multivariate analysis, and three fractions were obtained for each variety: large (L), medium (M) and small (S). These fractions were evaluated for hardness, water absorption rate and total water absorption. It was found that the small bean fraction of the varieties studied had the lowest hardness values in comparison to the medium and large fractions. This same behaviour was observed for the water absorption rate and total water absorption; the smaller beans absorbed water more quickly and had greater total water absorption than the other fractions. One kind of bean (Pinto Villa) proved to be much harder than the other varieties. The total water absorption increased and hardness decreased for beans with greater ash content, but no correlation was found between these two properties (water absorption and hardness) for protein and fiber content.
Table olives are prepared from the sound fruits of varieties of the cultivated olive tree ( Olea europaea L.) that are chosen for their production of olives whose volume, shape, flesh-to-stone ratio, fine flesh, taste, firmness and ease of detachment from the stone make them particularly suitable for processing. The world production in the crop year 2006/2007 is estimated at 1.8 million tons of table olives and in the last fifteen years it has constantly increased. Most of the Slovenian Istria table olive production is based on a modification of the Spanish style. Results of qualitative and quantitative sensory assessments of two olive cultivars, ‘Storta’ and ‘Istrska belica’, are presented. Sensory characteristics were determined after four and six months of fermentation. Texture differences between the two production systems were revealed. Significant decrease in hardness was determined after six months of fermentation with initial alkaline treatment. The effect of cultivar type was also evident. After four and six months, the bitterness of table olives produced by the traditional technology decreased and the olives were appropriate for consumption.
The objective of this work was to determine the effects of fatty acid composition of liquid margarines (LM) on the sensory properties of sponge cakes and compare it with cakes containing solid margarines and butter. Fats were different in principal groups of fatty acid and were of the following composition: SFA (9.3–66.4), TFA (1.2–10.3), PUFA (1.9–53.9%). The taste and aroma of cakes scored lower with increasing content of unsaturated FA, especially PUFA and higher with increasing content of SFA and TFA combined. With respect to taste and aroma, cakes containing LM scored lower in comparison to cakes containing butter, while the texture of such cakes was rated as high as cakes containing butter. Approximately 34–65% of young consumers perceived such cakes as “like very much” and “like moderately”, however, 5% of consumers described them as “dislike a lot”. The results of this study indicate that liquid margarines could be recommended for cakes in large-scale manufacture. Regarding recommendations of reducing the intake of TFA in processed foods, it is justified to replace hydrogenated vegetable by liquid fats for manufacture of bakery products.
Results are given on the milk clotting properties and casein hydrolytic behaviour of partially purified extracts of four new cysteine plant endopeptidases: balansain, hieronymain, asclepain f, and philibertain g. Milk coagulation behaviour was different for the assayed proteases: balansain and hieronymain showed a similar performance, whereas asclepain f exhibited the lowest clotting activity; philibertain g exhibited the highest one when was previously incubated with cysteine. According to the relative ratio of clotting activity to proteolytic activity, balansain, philibertain g and hieronymain appear as possible vegetable rennets. Casein hydrolysates were produced with each enzyme and the hydrolysis pattern was analysed by tricine SDS-PAGE. The α S2 - and α S1 -casein fractions, associated with cheese texture, showed different degradation patterns: higher degradation kinetics was obtained for philibertain g, followed by balansain and hieronymain, whereas asclepain f showed the lowest activity. The β-casein fraction, related to bitterness, showed similar initial degradation kinetics for balansain and asclepain f; degradation was faster in the case of philibertain g and slower for hieronymain. In the case of the κ-casein fraction, involved in milk clotting, the most remarkable behaviour was that of hieronymain, as this casein fraction was quickly degraded by the protease.
Sensory acceptance of four trials of probiotic petit-suisse cheese was investigated. Cheeses were prepared using Streptococcus thermophilus TA 040 as starter not supplemented with any probiotic culture (T1-control), Lactobacillus acidophilus La-5 (T2), Bifidobacterium animalis subsp. lactis BL04 (T3) and L. acidophilus + B. animalis subsp. lactis (T4). Sensory acceptance tests were performed after 7 and 14 days of storage at 4±1 °C, using a 9-point hedonic scale to evaluate flavour, texture and overall acceptability. The population of La-5 and BL04 remained at 7.0 log CFU g −1 and at 8.0 log CFU g-1, respectively, during storage for up to 28 days. After 7 and 14 days of storage, cheese T4 presented the highest sensory acceptance for all attributes evaluated and differed significantly from the other cheeses (P<0.05). After 14 days of storage, cheese T3 presented the lowest acceptance and differed significantly from the other cheeses (P<0.05). The supplementation of petit-suisse cheese T4 with both La-5 and BL04 in coculture with a starter culture resulted in a product with high probiotic populations during storage and excellent sensory acceptance. The results also showed that, when added separately, La-5 and BL04 did not affect the sensory acceptability of petit-suisse cheese.
The influence of a food-grade long-chain polyphosphate mixture on the growth and survival of spoilage micro-organisms during storage in an experimental processed cheese spread formulation was evaluated. The emulsifying salt was added to the cheese blend at a concentration of 0.5% or 1.0%. A control product was also manufactured, which contained monophosphate instead of polyphosphate as emulsifying salt, with all other ingredients being identical to those in the experimental processed cheese spread. Half of the finished products were subjected to accelerated shelf-life testing at 37 °C for 10 days, whereas the other half of them was stored refrigerated at 4 °C for 120 days. Microbiological analyses (enumeration of viable cell counts, mesophilic sulphite-reducing clostridia, coliforms, yeasts and moulds) and sensory tests were performed at regular intervals. The results showed that polyphosphates had a beneficial effect on the shelf-life of the processed cheese spread tested in that they significantly reduced (P<0.05) the growth or survival rates of spoilage bacteria, especially of mesophilic sulphite-reducing clostridia. Polyphosphates also beneficially influenced the sensory, including textural properties of the experimental processed cheese spread. All the samples containing less than 1% polyphosphate showed signs of butyric blowing significantly earlier (P<0.05), during both accelerated shelf-life tests and regular refrigerated storage, than did the products fortified with 1% polyphosphate. In conclusion, the suitability of the long-chain polyphosphate formulation tested for shelf life extension of processed cheese spreads was demonstrated.
Microwave vacuum drying is a novel and mild food preserving technology. Beside its basic preserving function, it can be combined with other technologies, like hot-air drying. As a result of this combination, special snack can be produced from apple. The product is characterized by its unique consistency, high nutritional value, and consumer preference. In this work physical (dry mass content, hardness, bulk density, and colour), sensory (appearance, colour, odour, taste, texture) and nutritional (antioxidant activity and total phenolics) properties of dried apple snack were investigated as a function of pre-drying, microwave energy input, and batch weight. For evaluation of data, central composite experimental design was applied. According to the results, the physical properties of products produced by microwave vacuum drying combined with hot-air pre-drying (CMVD) mainly depend on the specific energy input. Higher specific energy input results higher dry mass content, which is associated with harder consistency, lower bulk density, and positive consumer perception as well. Bulk density had an optimum point of batch weight at 336 g. Higher value of pre-dried dry mass content resulted lighter colour but less antioxidant activity and less total phenolics, therefore shorter hot-air drying and prolonged microwave vacuum drying is recommended.
