Substitution of Pork Fat by Emulsified Seed Oils in Fresh Deer Sausage ('Chorizo') and Its Impact on the Physical, Nutritional, and Sensory Properties.

Meat products are consumed worldwide, but their high content of saturated fatty acids requires a reformulation of that type of food. In this regard, the objective of this study is to reformulate 'chorizos' by replacing the pork fat with emulsified seed oils from seeds (50%, 75%, and 100%). Commercial seeds (chia and poppy) and other seeds considered wastes from the agri-food industry (melon and pumpkin) were evaluated. Physical parameters, nutritional composition, fatty acid profile, and consumer evaluation were analyzed. The reformulated chorizos presented a softer texture but a better fatty acid profile due to their decrease in saturated fatty acids and their increase in linoleic and linolenic fatty acids. Regarding consumer evaluation, all the batches were positively evaluated in all the parameters studied.

Evolution of Virgin Olive Oil during Long-term Storage.

In this work, the evolution of virgin olive oil from 4 olive varieties when stored at 5°C, 10°C and 20°C for a period of up to 3 years was studied. Free acidity increased progressively for the 4 varieties, staying below the limit for extra virgin olive oil, even at the highest temperature. The peroxide value also increased, reaching its maximum after about 28 months of storage, when some samples stored at 20°C exceeded the limit for extra virgin olive oil. The maximum values for K270 and K232 were reached at the end of the storage period, also exceeding the limit for extra virgin olive oil in the case of some varieties stored at 20°C. Oxidative stability decreased by 38%-50% depending on the storage temperature and the variety. Most of the color indexes increased in value because of the degradation of the oil pigments.

Storage stability and composition changes of three cold-pressed nut oils under refrigeration and room temperature conditions.

Chemical composition and stability parameters of three cold-pressed nut oils (almond, walnut and pistachio) were monitored for up to 16 months of storage at 5 °C, 10 °C, 20 °C and room temperature. Freshly pressed pistachio oil had lower peroxide value than almond oil and higher induction period than almond and walnut oils, indicating a higher stability. The peroxide values increased faster at room temperature than at lower temperatures during the storage time, and the highest increase was for pistachio oil stored at room temperature exposed to daylight. The induction period decreased for all three nut oils during the storage time, regardless of the storage conditions. Pistachio oil remained the most stable oil at the end of the storage time, followed by almond oil. The percentage of polyunsaturated fatty acids decreased slightly throughout the storage.

Quality and Composition of Virgin Olive Oil from Varietties Grown in Castilla-La Mancha (Spain).

The regulated physicochemical quality parameters (free acidity, peroxide value and UV absorption characteristics), sensory parameters (median of fruity, median of defect, panel classification, bitterness and pungency), stability parameters (total phenols and oxidative stability at 100°C) and chemical composition (fatty acids, sterols and triterpenic dialcohols) of virgin olive oils obtained from 12 olive varieties cultivated in 6 of the most representative zones of Castilla-La Mancha (La Alcarria, Campos de Calatrava, Campos de Hellín, Campos de Montiel, Montes de Toledo and Sierra de Alcaraz) were evaluated. The varieties Cornicabra and Picual showed remarkable total polyphenols content and high stability, in contrast with Arbequina. The other less common varieties were in-between these two groups. Cornicabra and Picual showed also high oleic and low linoleic acids content, while Arbequina showed low oleic, high linoleic high palmitic and high palimitoleic acid content. The varieties Benizal and Cornicabra showed very high campesterol content. Benizal stood out by its high stigmasterol, low apparent ß-sitosterol and low total sterols content, and the latter was below the established limit for olive oil. Triterpenic dialcohol content was significantly lower for Arbequina than for Cornicabra.

Preservation of saffron floral bio-residues by hot air convection.

Large amounts of floral bio-residues are wasted in saffron spice production, which need to be stabilized because of how quickly they deteriorate. These bio-residues are rich in phenolic compounds, and the aim of this study was to evaluate the effect of drying temperatures and air flows on their color and phenolic composition. Anthocyanins and flavonols were degraded at 110 and 125°C. The best drying temperatures were 70 and 90°C for maintaining their physicochemical quality. The duration at 70°C was double than that of 90°C. Anthocyanins and flavonols were stable at 70 and 90°C with 2, 4, 6 and 8ms(-1). Dehydrations at 90°C with 2, 4 and 6ms(-1) were the most appropriate, due to a better color and greater similarity to control samples for their flavonols and anthocyanins.

Characterization of oil obtained from grape seeds collected during berry development.

The surpluses of the wine industry that originate from wine production in the European countries must be reduced. Green harvesting, consisting in collecting the grapes when they are still green, could contribute to the reduction of the yield of vineyards. The green grapes are not suitable for wine production, but they can be used for seed oil extraction. Grape seed oil is a linoleic acid rich oil that has been suggested as an alternative to traditional vegetable edible oils. In this work, grape samples were collected at different stages during berry development for seed oil extraction. The grapes collected at a very early stage showed a very low oil extraction yield compared with that of the samples collected at later stages. The oil from the grapes collected at an early stage had considerably higher sterols content and had a significantly different fatty acid composition compared with those of the oil extracted from grapes collected at later stages. However, the oil samples from grapes collected before veraison did not show significant differences with samples collected after veraison as regards oil extraction yield, fatty acids composition, and total sterol content and composition. Our data suggest that grapes collected from green harvesting near veraison could be suitable for seed oil extraction, with characteristics similar to those of the oil extracted from the seeds of mature grapes.

Influence of different drying and aging conditions on saffron constituents.

A dehydration postharvesting treatment is necessary to convert Crocus sativus L. stigmas into saffron spice. Three different dehydration treatments were evaluated: dehydration at room temperature; dehydration with hot air at different temperatures (70, 90, and 110 degrees C); and dehydration following traditional processing in Castille-La Mancha (Spain) with three different heating sources (vineshoot charcoal, gas cooker, and electric coil). The time (between 28 and 55 min) and mean temperature (between 54 and 83 degrees C) conditions for traditional dehydration were established for the first time. The highest coloring strength was obtained when saffron was submitted to higher temperatures and lower times. These findings may be supported by the fact that samples dehydrated at high temperature were more porous than those dehydrated at room temperature, as was observed by scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). The higher the temperature during the process, the higher the proportion of trans-crocetin di-(beta-D-gentibiosyl) ester, although trans-crocetin (beta-D-glucosyl)-(beta-D-gentibiosyl) and trans-crocetin di-(beta-D-glucosyl) ester decrease while cis-crocins did not change significantly. A thermal aging process reveals that the trans-crocetin di-(beta-D-gentibiosyl) ester increases when saffron is resubmitted to a heating treatment before it is decomposed by the extreme conditions. The picrocrocin extinction during the aging process does not imply a consistent generation of safranal.

High-Temperature Short-Time Inactivation of Peroxidase by Direct Heating with a Five-Channel Computer-Controlled Thermoresistometer †.

The thermal inactivation kinetics of horseradish and asparagus peroxidase in high-temperature short-time conditions was studied by heating in a five-channel computer-controlled thermoresistometer. Horseradish peroxidase was heated between 111.5 and 145°C and the reaction was analyzed assuming that two isoenzymes with EaL = 44.1 and Eas = 22.0 kcal/mol were present. Asparagus peroxidase heated from 110 to l20°C reacted with first-order kinetics, with Ea = 20 kcal/mol. The five-channel computer-controlled thermoresistometer enabled us to study the inactivation kinetics of the more labile fraction of horseradish peroxidase at temperatures above 100°C; this equipment was suitable for studying the heat resistance of peroxidase at high temperatures.

Inactivation and Regeneration Kinetics of Horseradish Peroxidase Heated at High Temperatures.

The inactivation kinetics of horseradish peroxidase (HRP) heated in capillary tubes in the range 110 to 135°C was studied. Its regeneration kinetics when stored at 4 and 25°C was also considered. As the severity of the treatment increased, the absolute value of the regeneration decreased. The storage temperature of the enzyme did not affect the percentage of maximum activity regenerable, although when this temperature was raised from 4 to 25°C the speed of regeneration increased. Kinetics of HRP inactivation determined after heating and after regeneration were compared. Both forms of the enzyme showed similar behavior with first-order inactivation kinetics, with Ea = 19.5 ± 1.0 kcal/mol and k120°C = 3.7 ± 0.2 min-1, and Ea = 18.8 ± 1.2 kcal/mol and k120°C = 3.7 ± 0.2 min-1, respectively.

Thermal Inactivation at High Temperatures and Regeneration of Green Asparagus Peroxidase.

A spectrophotometric method was developed for determining the peroxidase activity of green asparagus in small samples. The optimum conditions for the analysis in the cuvette were 45 mM of H2O2 36 mM of guaiacol, and pH 7. The method can be used to determine enzyme activity at up to two decimal reductions. A study was performed of the regeneration and inactivation kinetics of the enzyme when heated between 90 and 125°C. Regenerated asparagus peroxidase reached its maximum activity after being stored 6 days at 25°C. The regenerated enzyme followed first-order inactivation kinetics, showing an Ea = 13.62 kcal/mol and k100°C = 2.07 min-1.