Effect of Lactose-Reduction in Murciano-Granadina Semi-Hard Goat Cheese on Physicochemical and Sensory Characteristics.

Semi-hard pressed goat's cheese, a traditional matured cheese in Andalusia, has a residual lactose content that may affect people with intolerance to that carbohydrate. Nowadays, lactose-free dairy products are characterized by presenting a scant sensory quality, far removed from their traditional profile for their pronounced sweet and bitter taste and aroma related to Maillard reactions. The aim of this work was to make a cheese with a similar sensory profile to that of the traditional Andalusian one but without lactose. For this purpose, the doses of the enzyme lactase that would be necessary to add to the milk were investigated so that, during the manufacturing of the cheese, there would remain enough lactose for the starter cultures to trigger lactic fermentation and, in turn, to spark the cheese's own maturity processes. The results show that the combined action of lactase (0.125 g/L, 0.250 g/L, 0.5 g/L, and 1 g/L) and of the lactic bacteria reduces the final content of lactose to below 0.01%, complying with the European Authority of Food Safety's recommendations for considering the cheeses as being under the denomination "lactose-free". The physicochemical and sensory values resulting from the different batches of cheese obtained indicate that the lowest dose studied (0.125 g/L) had very similar ones to those of the control cheese.

Physicochemical Composition, Antioxidant Status, Fatty Acid Profile, and Volatile Compounds of Milk and Fresh and Ripened Ewes' Cheese from a Sustainable Part-Time Grazing System.

We conducted the first nutritional analysis of dairy products from the traditional Roja Mallorquina sheep breed. Samples of bulk raw milk were taken twice a month from December 2015 to March 2016 from sheep fed using a part-time grazing system, and fresh soft (FC, n = 8) and ripened (RC, n = 8) cheeses were made. The variability in vitamins, total phenolic compounds (TPC), total antioxidant capacity (TAC), and fatty acid (FA) content was influenced by the cheese-making process (differences between the cheese and the original milk) and by the type of cheese-making technology (mainly related to heating, the use of starter culture, and ripening). The most notable physicochemical characteristic of the cheeses was low fat content (24.1 and 29.6 g/100 g for FC and RC). Milk and RC were characterised by major concentrations of retinol (211.4 and 233.6 µg/100 g dry matter (DM), respectively) and TPC (18.7 and 54.6 µg/100 g DM, respectively), while FC was characterised by major concentrations of retinol (376.4 µg) and α-tocopherol (361.7 µg). The fat-soluble components of the FC generally exhibited better nutritional value for human health than those of the milk and RC, with a higher level of retinol and α-tocopherol; lower values for saturated FA, atherogenic, and thrombogenic indices; and higher levels of monounsaturated FA, polyunsaturated FA, n-3, and n-6. Acids, alcohols, and ketones comprised almost 95% of the volatile compounds detected. Acetoin and products of lactose and citrate metabolism played an important role in the development of the aromatic attributes of both kinds of cheese. This preliminary study can contribute to add value to these traditional products according to healthy nutritional criteria and supports the implementation of strategies to promote their commercialisation and obtain product labelling as "pasture-fed" or specific marks.

Effect of Citrus By-product on Physicochemical Parameters, Sensory Analysis and Volatile Composition of Different Kinds of Cheese from Raw Goat Milk.

The increased use of concentrates to reduce pasture as a feed source in productive systems like Payoya breed goat farms has made it necessary to decrease feeding costs. The inclusion of agro-industry by-products such as dry orange pulp pellets in goat diets has been suggested as a sustainable alternative to cereal-based concentrates. The aim of this work was to assess the influence of diets including dry orange pulp pellets on the quality of cheeses traditionally made from Payoya breed goat milk. We analysed the physicochemical characteristics, sensory properties and volatile compound profiles of 18 artisanal cheeses made from raw Payoya milk. In this study, goats were fed with different concentrations of dry orange pulp; and cheeses were curdled with animal and vegetable coagulants. Slight differences were detected between some cheeses. However, the use of citrus by-products in the Payoya goat diets did not substantially affect the cheeses' physicochemical properties, olfactory attributes, or volatile profiles. Therefore, dried citrus pulp can be used as a substitute for cereal concentrates without affecting the distinct properties of these ripened raw goat milk cheeses.

Sensory Profile and Physico-Chemical Properties of Artisanal Honey from Zulia, Venezuela.

The physico-chemical parameters and the sensory profile were determined in honeys from apiaries of the Mara and Maracaibo of Zulia State (Venezuela). The analysis of variance showed that there were no significant differences in the mean value between apiaries for most of the physicochemical parameters and sensory attributes. The obtained value for pH (3.58-4.08), free acidity (30.9-36.0 meq/kg), lactone acidity (9.0-14.3 meq/kg), total acidity (42.1-46.0 meq/kg), moisture content (19.1-20.0%), diastase activity (8.11-12.7 ºG), colour intensity (41.5-86.6 mm Pfund), hydroxymethylfurfural (15.7-26.0 mg/kg), and electrical conductivity (0.33-0.52 mS/cm) were within the criteria set by international quality regulations. The sensory profile of these honeys is characterized by being amber in colour, with a floral, acid fruit, balsamic and animal odour/aroma, a sweet, slightly acid taste, and by being fluid and of a medium persistence.

Quality assessment of olive oils based on temperature-ramped HS-GC-IMS and sensory evaluation: Comparison of different processing approaches by LDA, kNN, and SVM.

For the first time, this study describes a HS-GC-IMS strategy for analyzing non-targeted volatile organic compounds (VOCs) profiles to distinguish between virgin olive oils of different classification. Correlations among measured flavor characteristics and sensory attributes evaluated by a test panel were determined by applying unsupervised (PCA, HCA) and supervised (LDA, kNN and SVM) chemometric techniques. PCA and HCA were applied for natural clustering of the samples and LDA, kNN, and SVM methods were used to create predictive models for olive oil classification. Identification of 26 target compounds revealed which compounds are responsible for discrimination, and how their distribution correlates with the sensory evaluation. In the investigated samples, LDA, kNN, and SVM models correctly classified 83.3%, 73.8%, and 88.1% of the samples, respectively. This suggests that mathematical correlations of HS-GC-IMS 3D fingerprints with the sensory analysis may be appropriate for calculating a good predictive value to classify virgin olive oils.