Catálogo de publicaciones - revistas

<jats:p> Among the different factors that influence the acceptance or rejection of food, attitudes, beliefs and opinions of their potential consumers are relevant and can in some cases be decisive. The influence of these factors on food choice and purchase is especially important in the acceptance of some types of foods (organic or ecological, genetically modified or functional) that are presented to the consumer as a possible alternative to conventional food. This review paper describes the main qualitative and quantitative methods applicable to the investigation on the consumers’ opinions and attitudes towards food. Comments are made on some of the features of the information gathered. </jats:p>

<jats:p>The effect of coating, hot-air and microwave drying on the texture, microstructure and rehydration characteristics of Golden Deliciousapple slices (22mm diameter, 4mm thickness) was investigated. Blanching was carried out in hot water (80°C, 1 min) to prevent undesirable enzymatic reactions. To induce a porous structure during microwave treatment, coating with a starch (suspension), pectin and carboxymethylcellulose (CMC) solution (20 g/L) with and without CaCl<jats:sub>2</jats:sub>(10 g/L) was carried out. A puncture test and a scanning electron microscopy (SEM) technique were used to analyse the effects of these processes on texture and microstructure. Rehydration in distilled water was also studied. Coating, air-drying (70°C, 1.5 m/s) and microwave treatment (300W, 10s) resulted in the production of puffed and porous products. Microstructure of samples coated by starch and pectin with CaCl<jats:sub>2</jats:sub>improved. Coating had a beneficial effect on the microstructure of samples after microwave treatment. In addition, microstructural studies showed that coating with pectin had a significant effect on the thickness of the cell wall whereas those treated with starch or CMC did not exhibit such an effect. Adding CaCl<jats:sub>2</jats:sub>to the coating solution improved the microstructural properties and prevented central heating phenomena.</jats:p>

<jats:p> In this work a methodology to evaluate the sensory properties of honeys has been developed. The sensory analysis was carried out by means of a quantitative descriptive analysis (QDA) method, based on several reference scales, for the coverage of the designed range for each descriptor. The peculiarity of this sensory analysis is that the reference scales have been constituted by common foodstuffs agreed upon by consensus of the panel. The main sensory attributes evaluated in the analyses were: adhesiveness, viscosity, bitterness, aroma, sweetness, acidity, color and granularity. Both the intensity and persistence of honey aromas have also been estimated, together with the classification of the identified aromatic attributes into different groups. The method was applied to 55 artisanal honeys from Madrid (Spain) with the following results: (i) the developed sensory profile sheet allowed a satisfactory description of Madrid honeys; (ii) correlations between sensory attributes of three broad groups of Madrid honeys were obtained and (iii) aroma persistence, sweetness, bitterness, color and granularity appeared as the main sensorial characteristics of honey with discrimination power between floral and honeydew honeys. </jats:p>

<jats:p> The aim of this work was to study the influence of the binary and ternary combinations of bovine plasma proteins (BPP), inulin (I) and κ-carrageenan (C) in the overall quality of fat-reduced sausages. The influence of these components over different properties (chemical composition, weight loss after cooking, emulsion stability, texture profile and sensory analysis of fat-reduced sausages) was studied and compared against two samples, one without fat reduction and another a fat-reduced sample without addition of texturing agents. In this sense, a full factorial experimental design of two levels with central point was used. The samples containing BPP+I and BPP+C showed a synergy in which the binary combinations presented higher values of moisture and protein content than the samples containing the individual components. The reduction of fat content increases the values of hardness and decreases the values of springiness. Samples with 5% BPP (w/w) and binary combinations of BPP+C and BPP+I had the best stability values (low total fluid loss), demonstrating a significant synergistic effect by combining BPP+C. Similar results were obtained from the study of weight loss after cooking. However, both studies showed a destabilization of the sample BPP+I+C as emulsion stability decreased and weight loss increased after cooking compared to binary combinations ( P &lt; 0.05). Samples with a binary combination of BPP+C and BPP+I do not present a statistically significant difference in the chewiness with respect to a not-fat-reduced commercial sample ( P &gt; 0.05). The less acceptable sample for flavor and texture was the one containing only BPP. However, when BPP combined with I or C, a major acceptability was obtained, demonstrating the synergistic effect of these binary combinations. Therefore, our studies revealed that the binary combinations of BPP with I or C are good alternatives for the development of fat-reduced sausage. </jats:p>

<jats:p> The aim of this study was to assess the effect of O<jats:sub>3</jats:sub> treatment on the quality of different cultivars of apples ( Malus domestica Borkh.). Apples were stored for six months at different concentrations of ozone. During the research, minor differences between ozone-treated and control fruits were found in terms of cell integrity and epicuticular wax structure. Ozone application for apple treatment could accelerate the natural ageing of the waxes found on the surface of apples, thereby reducing the thickness of the waxes. The rate of degradation for the epicuticular wax was found to be cultivar dependent. After six months of storage, the ozonation process prevented the decay of ‘Iedzenu’, ‘Auksis’ and ‘Belorusskoje Malinovoje’ apple cultivars, but it accelerated damage in the ‘Gita’ apple cultivar. A positive impact of ozone during long-term storage was found regarding flesh firmness of ‘Iedzenu’ apple cultivar samples subjected to O<jats:sub>3</jats:sub> exposure at concentrations of 0.8 ppm and 3.0 ppm. In other cultivars of apples, significant differences between ozonation and cold storage (control) were not found. In general, ozone treatment has a potential to be applied in order to maintain the sensory quality and biologically active compound level in apples during six-month storage; however, the degree of effectiveness depends both on the cultivar and on the concentration of ozone. </jats:p>

<jats:p>The purpose of this study was to explore the activity of bacteriocin enterocin KP and lactococcin BZ against Escherichia coli O157:H7, a Gram-negative foodborne pathogen, in ultra-high temperature (UHT) milks with different fat ratios. Enterocin KP and lactococcin BZ were produced from two bacteriocinogenic strains, isolated in previous studies from White cheese and Boza. Full fat (3.0%), half fat (1.5%), and low fat (&lt;0.1% fat) UHT milks inoculated with 10<jats:sup>2</jats:sup>, 10<jats:sup>4</jats:sup>, and 10<jats:sup>6</jats:sup>CFU/ml of E. coli O157:H7 were treated with different concentrations (400, 800, 1600, and 2500 AU/ml) of lactococcin BZ, enterocin KP, or a combination of both and stored at 4 or 20 ℃ for 20 days. The survival of E. coli O157:H7 was determined at both storage temperatures during the storage period of 20 days. Lactococcin BZ and enterocin KP had a bactericidal impact on E. coli O157:H7 in all UHT milk samples either separately or in combination. However, antibacterial activity of the bacteriocins decreased with increasing fat content of milk and inoculum levels of bacterium. The results of this study indicate that lactococcin BZ and enterocin KP may be useful candidates either separately or in combination as biopreservatives for use in the dairy industry to control the growth of pathogenic microorganisms.</jats:p>

<jats:p> Valorisation of an agroindustry by-product, through its uses as an ingredient, in the development of a product may be an opportunity for industries to reduce wastes; generating a valuable product rich in bioactive compounds. Nevertheless, as happens with every new product, food manufacturers follow the market trend ensuring that any new product or idea meets consumer’s expectations. The aim of this work is to study the expectation and the acceptability of consumers towards fibre-enriched cookies using blueberry pomace as a functional ingredient. A label for the blueberry cookies, created for this purpose, was evaluated by consumers who rated their expected liking when observing this label. Fibre-enriched cookies were formulated using blueberry pomace powder as source ingredient for antioxidant dietary fibre. A cookie without fibre was evaluated as a reference. Cookies were evaluated by a group of consumers who rated their degree of liking when tasting the sample under blind and informed conditions. Results showed that the consumer expectations were not fulfilled when assessing the product. Acceptability scores of blueberry pomace, fibre-enriched cookies show that most consumers are not willing to compromise hedonic aspects of cookies for their healthful attributes. Focus group was used to explore the characteristics a healthy cookie should have. Formulation of cookies must be optimised taking into account the acceptability of consumers. </jats:p>

<jats:p> Calçots are the immature floral stems of the second-year onion ( Allium cepa L.) resprouts. Modified atmosphere packaging or vacuum packaging are suitable alternatives to preserve fresh-cut vegetables. The objective of this study was to evaluate the effect of postharvest storage time of raw vegetable stored under controlled atmosphere and used packaging system after minimal processing on the quality of fresh-cut calçots. Calçots used for minimal processing were stored under 1.0 kPa O<jats:sub>2</jats:sub> + 2.0 kPa CO<jats:sub>2</jats:sub> at 1 ℃ for 30 and 60 days. Fresh-cut calçots were packaged using passive modified atmosphere packaging or vacuum packaging and were stored at 4 ℃ for 15 days. Calçots stored under controlled atmosphere for 30 days presented better retention of quality and in turn, being more suitable for minimally processing. Vacuum packaging preserved the physicochemical quality of fresh-cut calçots better after 15 days. Mesophilic aerobic counts were also higher in fresh-cut calçots stored under modified atmosphere packaging, but all counts were below the recommended limits during and at the end of their shelf-life (15 days). The most suitable conservation strategy might be to store whole calçots under controlled atmosphere for 30 days and after minimally processing, packaged under vacuum in order to extend the shelf-life of fresh-cut calçots. </jats:p>

<jats:p> Mixed gels of carrageenan (Car) and caprine whey protein concentrate (WPCc) (pH 7) were studied and compared with those prepared with Car and commercial bovine whey protein concentrate (WPCb). Dynamic rheology studies indicate that gels with WPCc were weaker (lower G′) than those made with WPCb. However, textural parameters such as, hardness, springiness and cohesiveness were similar in both type of gels. The addition of CaCl<jats:sub>2</jats:sub> incremented the elastic modulus (G′), hardness and adhesiveness of gels. The samples with caprine whey showed higher water holding capacity than samples with bovine whey. Confocal laser scanning microscope images of the gels, showed very different aspects according to the type of WPC used: WPCc-Car gels exhibited aggregates of proteins that interrupt the carrageenan network, while WPCb-Car gels showed a homogeneous appearance with proteins distributed throughout all the matrix. </jats:p>