Food Products with High Antioxidant and Antimicrobial Activities and Their Sensory Appreciation

(1) Background: The demand for healthy and nutritious food is growing worldwide. Fermented dairy products are highly valued by consumers for their health benefits. Kefir is a fermented dairy product that brings many benefits to the consumer due to its antioxidant, anticancer, antidiabetic, antihypertensive and antimicrobial properties. Extracts from various plants in the form of volatile oils have a beneficial efct on consumer health. their antioxidant and antimicrobial activities were demonstrated. (2) Methods: In the present study, the main purpose was to obtain a fermented dairy product with a high nutritional value; therefore, kefir, enriched with three types of volatile oils, namely, volatile mint oil, volatile fennel oil and volatile lavender oil, was made. The kefir samples obtained were sensory and texturally analyzed. The beneficial effect on health must also be studied in terms of the acceptability of these products by consumers from a sensory point of view. A non-numerical method based on several multi-personal approval criteria was used to interpret the results obtained in the sensory analysis. In the textural analysis, the consistency, cohesiveness and firmness of the kefir samples were analyzed. (3) Results: The samples enriched with volatile oils obtained superior results compared to the control sample in both conducted examinations. Kefir samples with volatile oils retained their sensory and textural characteristics for a longer time during storage. (4) Conclusions: The volatile oils added to kefir positively influenced the sensory and textural characteristics of the finished product.

Features of the morphology and texture of silica and carbon adsorbents

The morphological and textural characteristics of various silicas (93 fumed silicas and 56 porous silicas), different carbons (230), and porous polymers (53) are analyzed using probe (nitrogen, argon, benzene, n-decane, water) adsorption, small angle X-ray scattering (SAXS), and transition (TEM), scanning (SEM) electron and atom force (AFM) microscopies. There are certain correlations between pore volume (Vp) and specific surface area (SSA, SBET) for these materials. Synthesis and treatment temperatures affect this relationship since a linear Vp - SBET approximation scatter decreases with decreasing these temperatures. Silicas are composed of nonporous nanoparticles (NPNP), but activated carbons (AC) are composed of porous nanoparticles (PNP). For different materials, NP are weakly or strongly packed in secondary structures. However, there are general features of pore size distributions (PSD) for NP-based materials, e.g., minimal contribution of narrow mesopores of 3-5 nm in radius due NP-packing effects. For AC produced using the same chars and activation agents but with varied activation time, the textural characteristics demonstrate smooth changes with increasing burn-off degree: nanopores partially transform into narrow mesopores with opposite PSD shifts of broad mesopores and macropores. Comparison of adsorption (open pores accessible for probes) and SAXS (both open and closed pores) data for carbons shows that the difference decreases with increasing burn-off degree due to decreasing contribution of closed pores. Most clear pictures on the particulate morphology and texture could be obtained in parallel analysis using adsorption, SAXS, and microscopic methods with appropriate data treatments.

The Effect of Steaming Time on the Textural Characteristics of Two Sweet Potatoes with Different Flesh Colors

<p>Sweet potatoes have varied physical characteristics based on their flesh colors. Two selected sweet potato (SP) with white (WF) and yellow-fleshed (YF) colors were collected from local market and analyzed their textural characteristics using a Uniaxial compression and Texture Profile Analysis (TPA) test. The study was conducted in the Food Processing Technology Laboratory, Faculty of Food Science Technology, University of Putra Malaysia. All textural attributes were collected from the samples treated with steaming for 5, 10, 15 and 20 min. The moisture content of the samples were determined before and after steaming. The results showed that the moisture content of WF was lower than YF both before and after steaming, which could be declared as a typical moisture content for each flesh color. This resulted in a greater peak deformation or firmness of the fresh tuber found in WF relative to YF. Steaming SP for 5 min exhibited the “raw” properties tissue, whereas steaming for more than 10 min would generate the “cooked” tissue that significantly affected the textural characteristics. The hardness level decreased considerably along with the time of steaming and was similar for both flesh colors after 15-min steaming. The WF was less adhesive and less elastic; however, it had less chewiness than that of YF. This suggests that the use of WF as a raw material for mashed products would have advantages, such as easiness to mash, less tendency to stick with the cooking tools, and less elastic. <br /><br /></p>