Efficacy of Selected Powdered Floor Treatments Against Salmonella, E. coli, and L. monocytogenes on Polyurethane-Concrete Flooring Material Carriers.

Food processing environment flooring can become contaminated with pathogens in many ways including foot and equipment traffic, incoming materials, and floor drain backups.  Natural antimicrobial turmeric and commercially available powdered floor treatments may reduce the levels of pathogens on flooring thereby reducing the risk of cross contamination from the floor to food contact surfaces. These chemicals were evaluated to determine their effectiveness against cocktails of Salmonella , Escherichia coli , and Listeria monocytogenes dried onto the surfaces of carriers made from polyurethane-concrete commercial flooring material.  Aqueous test solutions were prepared from the minimum treatment required per m 2 from the manufacturer's instructions diluted in sterile water.  Potential synergy between turmeric and a percarbonate based commercial floor treatment was explored with a mixture of turmeric and sodium percarbonate, each at approximately 37g/m 2 application rate.  Each inoculated carrier was exposed to the treatment solutions or a sterile water control for 10 minutes at room temperature, neutralized with Hi-Cap neutralizing broth, the bacteria suspended, enumerated, and log 10 reductions calculated for each treatment and inoculum combination.  Mean log 10 CFU/carrier reductions with standard deviations ranged between 4.29±0.34 for the sodium percarbonate (SPC) based treatment and 0.004±0.23 for turmeric for Salmonella , 4.81±0.16 for SPC based treatment and -0.16±0.62 for turmeric for E. coli , and 4.88±0.6 for SPC based treatment and -0.16±0.15 for turmeric for L. monocytogenes .

Food Sustainability in the Context of Human Behavior.

The long-term goal of food sustainability is to produce enough food to maintain the human population. The intrinsic factors to guarantee a sustainable food system are a fertile land, water, fertilizers, a stable climate, and energy. However, as the world population grows, the volume of food needed in the future will not depend just on these intrinsic factors, but on human choices. This paper analyzes some of the human actions that may affect the sustainable future of the food supply chain, including diet, obesity, food miles, food waste, and genetically modified organisms.

Fermentation of Soybean Meal Hydrolyzates with Saccharomyces cerevisiae and Zymomonas mobilis for Ethanol Production.

Most of the ethanol currently produced by fermentation is derived from sugar cane, corn, or beets. However, it makes good ecological and economic sense to use the carbohydrates contained in by-products and coproducts of the food processing industry for ethanol production. Soybean meal, a co-product of the production of soybean oil, has a relatively high carbohydrate content that could be a reasonable substrate for ethanol production after fermentable sugars are released via hydrolysis. In this research, the capability of Saccharomyces cerevisiae NRRL Y-2233 and Zymomonas mobilis subsp. mobilis NRRL B-4286 to produce ethanol was evaluated using soybean meal hydrolyzates as substrates for the fermentation. These substrates were produced from the dilute-acid hydrolysis of soybean meal at 135 °C for 45 min with 0, 0.5%, 1.25%, and 2% H2 SO4 and at 120 °C for 30 min with 1.25% H2 SO4 . Kinetic parameters of the fermentation were estimated using the logistic model. Ethanol production using S. cerevisiae was highest with the substrates obtained at 135 °C, 45 min, and 0.5% H2 SO4 and fermented for 8 h, 8 g/L (4 g ethanol/100 g fresh SBM), while Z. mobilis reached its maximum ethanol production, 9.2 g/L (4.6 g ethanol/100 g fresh SBM) in the first 20 h of fermentation with the same hydrolyzate.

Tolerance of S. cerevisiae and Z. mobilis to inhibitors produced during dilute acid hydrolysis of soybean meal.

The objective of this research was to determine the minimum inhibitory concentration of 5-hydroxymethyl furfural, furfural, and acetic acid on Saccharomyces cerevisiae (NRRL Y-2233) and Zymomonas mobilis subspecies mobilis (NRRL B-4286) in both detoxified hydrolyzed soybean meal and synthetic YM broth spiked with the three compounds. Soybean meal was hydrolyzed with dilute sulfuric acid (0.0, 0.5, 1.25, and 2.0% wt v(-1)) at three temperatures (105, 120, and 135°C) and three durations (15, 30, and 45 min) followed by detoxification with activated carbon. Of all the combinations, only the treatments obtained at 135°C, 2.0% H2SO4, and 45 min and the one at 135°C, 1.25% H2SO4, and 45 min showed inhibition in the growth of the tested microorganisms. Spiked YM broths showed inhibition for the highest levels of inhibitors, either applied individually or in combination.

Effect of additives on subcritical water hydrolysis of whey protein isolate.

The objective was to examine the effect of the additives acetic acid, lactic acid, sodium bicarbonate, sodium chloride, and sodium hydroxide on the hydrolysis of whey protein isolate with subcritical water. A screening experimental design was used to study the effect of temperature, time, and additives. The most influential additive, sodium bicarbonate, along with temperature and time was used in a second experimental design to predict the treatment conditions to maximize the degree of hydrolysis and production of free amino acids. The maximum degree of hydrolysis achieved was 50% at a concentration of 1.24 M sodium bicarbonate, 291 °C, and 28 min. The highest concentration of total amino acids was 83.0 mg/g of whey protein isolate with 0.83 M sodium bicarbonate at 264 °C for 29 min. Compared to water alone, sodium bicarbonate increased the degree of hydrolysis 4-fold and the production of amino acids by 44% and decreased peptides' molecular weight.

Hydrolysis of whey protein isolate using subcritical water.

Hydrolyzed whey protein isolate (WPI) is used in the food industry for protein enrichment and modification of functional properties. The purpose of the study was to determine the feasibility of subcritical water hydrolysis (SWH) on WPI and to determine the temperature and reaction time effects on the degree of hydrolysis (DH) and the production of peptides and free amino acids (AAs). Effects of temperature (150 to 320 °C) and time (0 to 20 min) were initially studied with a central composite rotatable design followed by a completely randomized factorial design with temperature (250 and 300 °C) and time (0 to 50 min) as factors. SWH was conducted in an electrically heated, 100-mL batch, high pressure vessel. The DH was determined by a spectrophotometric method after derivatization. The peptide molecular weights (MWs) were analyzed by gel electrophoresis and mass spectrometry, and AAs were quantified by high-performance liquid chromotography. An interaction of temperature and time significantly affected the DH and AA concentration. As the DH increased, the accumulation of lower MW peptides also increased following SWH (and above 10% DH, the majority of peptides were <1000 Da). Hydrolysis at 300 °C for 40 min generated the highest total AA concentration, especially of lysine (8.894 mg/g WPI). Therefore, WPI was successfully hydrolyzed by subcritical water, and with adjustment of treatment parameters there is reasonable control of the end-products.