A Sustainable Material for Sheep's Cheese Wedges Stored under Different Atmosphere Conditions.

This study is based on the need to improve packaging sustainability in the food industry. Its aim was to assess the performance of a recyclable plastic material for semi-hard sheep's cheese wedges packaging as an alternative to conventional non-sustainable plastic materials. Four different packaging treatments (air, vacuum, and CO2/N2 gas mixtures 50/50 and 80/20% (v/v)) were studied. Changes in gas headspace composition, sensory properties, cheese gross composition, weight loss, pH, colour, and texture profile were investigated at 5 ± 1 °C storage for 56 days. The sensory analysis indicated that vacuum packaging scored the worst in paste appearance and holes, and air atmosphere the worst in flavour; it was concluded that cheeses were unfit from day 14-21 onwards. Air and vacuum packaging were responsible for most of the significant changes identified in the texture profile analysis, and most of these happened in the early stages of storage. The colour parameters a* and b* differentiated the air packaging from the rest of the conditions. As in previous studies using conventional plastic materials, modified atmosphere packaging, either CO2/N2 50/50 or 80/20% (v/v), was the most effective preserving technique to ensure the quality of this type of cheese when comparing air and vacuum packaging treatments.

Optimization of Modified Atmosphere Packaging for Sheep's Milk Semi-Hard Cheese Wedges during Refrigerated Storage: Physicochemical and Sensory Properties.

Modified atmosphere packaging (MAP) has become a good potential strategy to retain quality throughout the shelf life of perishable foods. The aim of this work was to evaluate different packaging atmospheres on semi-hard protected designation of origin Idiazabal cheese wedges. Six different packaging treatments (air, vacuum, and CO2/N2 gas mixtures in the ratio of 20/80, 50/50, 80/20, and 100/0% v/v, respectively) were studied. Changes in gas headspace composition, cheese gross composition, weight loss, pH, acidity, colour, and textural and sensory properties were investigated during 56 days of refrigerated storage at 5 ± 1 °C. MAP was the most effective preserving technique compared to air- and vacuum-packaging treatments. The cheese characteristics with the greatest discriminating weight in the preservation techniques were paste appearance, holes, flavour, a* (redness) and b* (yellowness) colour parameters, and slope to hardness. Air-packaged cheeses, on 35 day, presented a mouldy flavour. Vacuum packaging affected paste appearance (greasy, plastic marks, and non-homogeneous colour) and holes (occluded and unnatural appearance) starting after 14 packaging days. MAP mixtures with CO2 concentration between 50/50 and 80/20% CO2/N2 (v/v) are recommended to ensure sensory quality and stability in the distribution of these raw sheep-milk cheese wedges.

A Review of the Preservation of Hard and Semi-Hard Cheeses: Quality and Safety.

Cheese is a dairy product with potential health benefits. Cheese consumption has increased due to the significant diversity of varieties, versatility of product presentation, and changes in consumers' lifestyles. Spoilage of hard and semi-hard cheeses can be promoted by their maturation period and/or by their long shelf-life. Therefore, preservation studies play a fundamental role in maintaining and/or increasing their shelf-life, and are of significant importance for the dairy sector. The aim of this review is to discuss the most effective methods to ensure the safety and sensory quality of ripened cheeses. We review traditional methods, such as freezing, and modern and innovative technologies, such as high hydrostatic pressures, chemical and natural vegetable origin preservatives, vacuum and modified atmosphere packaging, edible coatings and films, and other technologies applied at the end of storage and marketing stages, including light pulses and irradiation. For each technology, the main advantages and limitations for industrial application in the dairy sector are discussed. Each type of cheese requires a specific preservation treatment and optimal application conditions to ensure cheese quality and safety during storage. The environmental impact of the preservation technologies and their contribution to the sustainability of the food chain are discussed.

Simultaneous analysis of carotenoids and tocopherols in botanical species using one step solid-liquid extraction followed by high performance liquid chromatography.

Carotenoids and tocopherols from botanical species abundant in Atlantic mountain grasslands were simultaneously extracted using one-step solid-liquid phase. A single n-hexane/2-propanol extract containing both types of compounds was injected twice under two different sets of HPLC conditions to separate the tocopherols by normal-phase chromatography and carotenoids by reverse-phase mode. The method allowed reproducible quantification in plant samples of very low amounts of α-, ß-, γ- and δ-tocopherols (LOD from 0.0379 to 0.0720 µg g(-1) DM) and over 15 different xanthophylls and carotene isomers. The simplified one-step extraction without saponification significantly increased the recovery of tocopherols and carotenoids, thereby enabling the determination of α-tocopherol acetate in plant samples. The two different sets of chromatographic analysis provided near baseline separation of individual compounds without interference from other lipid compounds extracted from plants, and a very sensitive and accurate detection of tocopherols and carotenoids. The detection of minor individual components in botanical species from grasslands is nowadays of high interest in searching for biomarkers for foods derived from grazing animals.

Rapeseed and sunflower oilcake as supplements for dairy sheep: animal performance and milk fatty acid concentrations.

The influence of different amounts of oilseed cake (rapeseed and sunflower) on animal production parameters and fatty acid (FA) concentrations of the milk was studied in a Latxa dairy sheep experimental flock, both in winter (50% oilcakes; indoor feeding) and in spring (30% oilcakes; part-time grazing). The two different levels of the oilcakes tested did not affect animal production parameters or milk yield. Milk fat content and the fat/protein ratio decreased significantly with 30 and 50% sunflower cake. Yet, fat/protein ratio values were within the range for cheesemaking. Both levels of either type of oilcake tested significantly increased the concentrations of nutritionally interesting FA (CLA isomer C18:2cis-9, trans-11, vaccenic, oleic, and total unsaturated FA), while simultaneously decreasing the concentration of atherogenic FA. The atherogenicity indexes of milks from ewes fed 50 or 30% of either oilcake were significantly lower than those of their corresponding control. The use of cakes in winter increased the concentration of nutritionally interesting FA to the values obtained with part-time grazing.

Effects of seasonal changes in feeding management under part-time grazing on terpene concentrations of ewes' milk.

Terpene composition of ewes' raw milk from nine commercial flocks was analysed from February to July. Ewes' diet consisted of concentrate and conserved forage in winter (indoor feeding) and part-time grazing from spring (transition and outdoor feeding). Regardless of the feeding, limonene and ß-phellandrene were the most abundant monoterpenes and ß-caryophyllene showed the highest concentrations among sesquiterpenes. Terpene content increased in the milks of commercial flocks when animals were reared under grazing management. Monoterpenes were detected in the milks of all the commercial flocks throughout the season, whereas sesquiterpenes were only detected in the milks from flocks grazing on non-cultivated community-owned grasslands in which a higher biodiversity of plant species grew. These preliminary results indicated that ß-caryophyllene could be a potential pasture-diet marker in the case of milks from animals grazing a higher biodiversity of plant species but in-depth studies including information on terpene composition of plants ingested by the animals are necessary to evaluate the suitability of ß-caryophyllene or another terpenoid compound as pasture biomarker.