Influence of Variety and Storage Time of Fresh Garlic on the Physicochemical and Antioxidant Properties of Black Garlic.

Black garlic is made from the fresh kind, submitting it to a controlled temperature (~65 °C) and humidity (>85 °C) for a prolonged period of time. The aim of this study was to assess the differences in the process and in the final product as a result of employing three garlic varieties (Spanish Roja, Chinese Spring and California White), and to check the influence of the storage time on fresh garlic in the quality of the final product by using garlic obtained in two different agricultural seasons, that of the current year (2014) and of the previous one (2013). The results revealed some differences in the parameters analysed during the manufacturing of the black garlic from the three varieties used, and even according to the harvest in question. However, when comparing initial and final values of the samples, a very similar evolution in their acidity, reducing sugars, °Brix, pH, polyphenol content, and antioxidant capacity was noted.

Evolution of some physicochemical and antioxidant properties of black garlic whole bulbs and peeled cloves.

Black garlic was processed at three different temperatures of heat treatment (72°, 75° and 78°C) and close to 90% of relative humidity. Two types of material source were used: whole bulbs and peeled cloves. Total soluble solids content (°Brix), pH, water activity (aw), browning intensive (L value), total polyphenol content, antioxidant capacity and total polyphenol index of the raw and heated garlic were determined. This study showed the changes occurring in the physicochemical and antioxidant properties of the garlic during the heat-treatment evolution. The soluble solids content (°Brix) in garlic increased gradually and the pH decreased in whole bulbs and peeled garlics. The polyphenol content measured by the Folin-Ciocalteu method showed a significant increase during the heat-treatment in all the cases. Also, the antioxidant capacity measured by the ABTS radical increased significantly during the heat-treatment.

Descriptive sensory analysis in different classes of orange juice by a robust free-choice profile method.

Free-choice profile (FCP), developed in the 1980s, is a sensory analysis method that can be carried out by untrained panels. The participants need only to be able to use a scale and be consumers of the product under evaluation. The data are analysed by sophisticated statistical methodologies like Generalized Procrustean Analysis (GPA) or STATIS. To facilitate a wider use of the free-choice profiling procedure, different authors have advocated simpler methods based on principal components analysis (PCA) of merged data sets. The purpose of this work was to apply another easy procedure to this type of data by means of a robust PCA. The most important characteristic of the proposed method is that quality responsible managers could use this methodology without any scale evaluation. Only the free terms generated by the assessors are necessary to apply the script, thus avoiding the error associated with scale utilization by inexpert assessors. Also, it is possible to use the application with missing data and with differences in the assessors' attendance at sessions. An example was performed to generate the descriptors from different orange juice types. The results were compared with the STATIS method and with the PCA on the merged data sets. The samples evaluated were fresh orange juices with differences in storage days and pasteurized, concentrated and orange nectar drinks from different brands. Eighteen assessors with a low-level training program were used in a six-session free-choice profile framework. The results proved that this script could be of use in marketing decisions and product quality program development.