Development of a Functional Food Product Using Guavas

The global market of functional foods and demand for a healthy lifestyle among consumers in recent years is growing. Guava is a highly perishable fruit and a rich source of vitamin C. Guava Cheese (GC) is a semi-solid concentrated fruit product that could be consumed as a snack. The objectives were to develop a guava cheese (GC) and determine the antioxidant potential of the product. Formulation consisted of guava puree with added sucrose or agave, chia seeds and almonds. Pectin was added at select concentrations (0.5%, 1%, 1.5%) along with citric acid to enhance the consistency of GC. Physiochemical and sensory parameters were analyzed for extended shelf life (3 months) studies. Moisture content, pH, water activity, color (L*, a*, b*) and texture profile analysis (hardness, springiness, cohesiveness, gumminess, chewiness) did not change over the 90-day period. Ash, protein and fat contents of 0% pectin were 2% lower than GC with pectin. Sensory parameters (firmness, mouthfeel, flavor and overall acceptability) of GC 0% pectin and 1% GC were similar. Total content in 0%, 0.5%, 1%, and 1.5% pectin added GC were 150.49 ± 32.76, 340.17 ± 54.65, 346.39 ± 53.04, and 355.72 ± 14.24 mg gallic acid equivalent (GAE)/100g. Flavonoid content in 0%, 0.5%, 1%, and 1.5% GC were 159.73 ± 13.31, 332.77 ± 13.31, 341.65 ± 15.37, and 350.52 ± 16.60 mg catechin equivalent (CE)/100g. Similarly, antioxidant of potential measure by DPPH radical scavenging was similar in all samples (IC50 at 0.8 mg/ml). Guava cheese may be utilized as a healthy fruit snack because of added alternative sweeteners and functional ingredients to obtain health benefits. Adding pectin to guava cheese improved functionality by increasing antioxidant potential as well as physical properties.

Chemopreventive Potential of Probiotics and Prebiotics

Utilization of probiotics and prebiotics in food products and in the diet supplemental form continues to gain interest because of their health benefits. Cancer is the leading cause of death and strategies for chemoprevention are important to reduce mortality and morbidity. Probiotics are gaining attention to use as preventive agents. Efficacy of their use as chemopreventive agents was established through research. This review focused on the mechanisms of prebiotics and probiotics action against cancer. Benefits of probiotics against cancer are attributed to competitive exclusion of pathogenic bacteria, direct physical binding to carcinogens, altering intestinal environment to modulate the production enzymes, antioxidant activity and immune modulation. Prebiotics are indigestible food components that could promote the growth of probiotics. Chemopreventive properties of prebiotics are due to their production of short chain fatty acids and enhancing the immunity of the host. Anticarcinogenic properties of pre- and probiotics result from a combination of events rather from a single event.

Modulation of Anti-Microbial Resistant <i>Salmonella heidelberg</i>Using Synbiotics (Probiotics and Prebiotics) in Two <i>In-Vitro</i>Assays (Cross-Streaking and Agar Wells Diffusion)

Salmonellosis is the most prevalent bacterial foodborne disease in many countries worldwide. Utilization of probiotics is one of the most accepted ways to reduce Salmonella, especially lactic acid bacteria, as it has proven to reduce the enteric pathogens in monogastric and ruminant livestock animals through different mechanisms such as antimicrobials production, competitive adhesion to the gastrointestinal tract, and immune stimulation. Prebiotics could be utilized solely for health benefits as an alternative to probiotics or in addition to probiotics for a synergistic effect known as synbiotics. The aim of this study was to compare effects of different probiotic strains (Lactobacillus acidophilus (La-14), Lactobacillus paracasei (Lpc-37), Streptococcus thermophiles (St-21), Bifidobacterium bifidum (Bb-06), and Aspergillus niger (ATCC®16888TM) and without prebiotics (Mannose;Xylose;Galactooligosaccharides GOS;Inulin;and Dandelion extract) on lowering Salmonella heidelberg CFU in vitro. Different inhibition levels probiotic strains were assessed and compared in the presence and absence of 2.5% prebiotic compounds using cross-streaking and agar well diffusion assays. Recommendations for the growth of selected microorganisms such as temperature and oxygen conditions were taken into consideration. All the analysis was conducted in triplicates. The results showed that all the probiotics strains except S. thermophiles were able to significantly (P < 0.05) inhibit the growth of S. heidelberg in at least one of the assays. The difference in inhibition percentage confirms that probiotic strains have multiple inhibition mechanisms, such as production of antimicrobials, lower pH by producing organic acids (acetic acid, lactic acid, etc.), and inhibition of pathogen’s virulence factor expression, and production of lipopolysaccharide solubilizing compounds.

Viscosity Effects of the Precursor Solution and Surface Structure of Gadolinium Oxide (Gd₂O₃) and Gadolinium Oxide Europium Doped (Gd₂O₃:Eu³⁺) Sol-Gel Films

The sol-gel method is a novel technique for the preparation of thin films. In this research, gadolinium oxide (Gd2O3) and gadolinium oxide europium doped (Gd2O3:Eu3+) films prepared via the sol-gel and dip coating methods were investigated. In addition to the elaboration on the sol-gel preparation routes and additional observations of the films’ surface morphology as characterized by scanning electron microscope (SEM), we determined via viscosity measurements that the sols were stable for 398 days. FTIR analysis of the Gd2O3 and Gd2O3:Eu3+ dip coated films was made to monitor the decomposition and oxidation reactions that occurred during processing as well as process stability.