This study investigates the possibilities of applying water generated from the atmosphere for agricultural processes, particularly hydroponic systems. A solar powered, off-grid greenhouse system is proposed as a theoretical solution to food production, in areas affected by water scarcity. Two experiments are conducted with the purpose of testing atmospheric water quality and how it performs in a hydroponic setting. The plausibility of powering said greenhouse system using solar energy is investigated, considering several available solar technologies. Ultimately, the footprint area required to install enough capacity to power the system is discussed, and the potential site of such a system is modelled and visualized. The experiments concluded that atmospheric water is likely suitable for hydroponic use. The study also found that the footprint area required for the greenhouse system probably can be considered reasonable for certain applications, but more research and advances within solar power technology would be beneficial | <p>2021-06-08</p>

The kinetics of light-induced riboflavin loss were examined in several liquid samples, such as skim milk and buffered riboflavin solution, and solid samples, such as elbow macaroni, particulate macaroni, and non-fat dried milk. First and second order kinetics were determined for the liquid and dry system, respectively. Light intensity, using 25, 50, or 100 foot-candles, did not affect riboflavin loss kinetics in elbow macaroni, but the use of a dim light only produced first order loss kinetics. Riboflavin loss in elbow macaroni increased relative to humidity. A quantitative high-performance liquid chromatographic method was used for riboflavin assay. Degradation rate constants are reported. (wz)

Recent research has shown exponentially increased thermal resistance of pathogenic bacteria at a reduced water activity (aw) in thermal treatments. However, information on aw change as affected by food components at high temperatures is limited. The objective of this project was to quantify the influence of major food components on aw changes in low-moisture foods at elevated temperatures. Corn starch, soy protein, coconut, and cheddar cheese powders were selected as high-carbohydrate, high-protein, high-fat, and intermediate products. Vacuum dried powders were equilibrated in the jars containing saturated salt solutions to different aw from 0.11 to 0.84 at 25 °C. The aw of food powders were measured from 25 to 80 °C in hermetically sealed test cells using hight-temperature humidity sensors. For a given initial aw, high-carbohydrate product had more considerable aw increase than high-protein, intermediate, and high-fat foods with increasing temperature. The net isosteric heat of sorption increased from high-fat, intermediate, high-protein, to high-carbohydrate food at same moisture content. These relationships support findings in the literature that bacterial cells are more easily inactivated in high-carbohydrate and high-protein products than in high-fat foods. Understanding the correlation between food components and aw change at elevated temperatures helps predict the thermal resistance of bacteria in low-moisture foods.

²H/¹H ratios in animal biomass reflect isotopic input from food and water. A 10-week controlled laboratory study raised 48 mice divided in two generations (8 mothers Mus musculus and their offspring). The mice were divided into four groups based on the combination of ²H, ¹³C, ¹⁵N-enriched and non-enriched food and water. Glycine, the most common amino acid in bone collagen, carried the ²H, ¹³C, ¹⁵N-isotopic spike in food. ANOVA data analysis indicated that hydrogen in food accounted for ∼81 % of the hydrogen isotope inventory in collagen whereas drinking water hydrogen contributed ∼17 %. Air humidity contributed an unspecified amount. Additionally, we monitored ¹³C and ¹⁵N-enrichment in bone collagen and found strong linear correlations with the ²H-enrichment. The experiments with food and water indicate two biosynthetic pathways, namely (i) de novo creation of non-essential amino acids using hydrogen from water, and (ii) the integration of essential and non-essential amino acids from food. The lower rate of isotope uptake in mothers’ collagen relative to their offspring indicates incomplete bone collagen turnover after ten weeks. The variance of hydrogen stable isotope ratios within the same cohort may limit its usefulness as a single sample proxy for archaeological or palaeoenvironmental research.