Food Science Research: April/May 2022

Roast Level and Brew Temperature Affect the Color of Brewed Coffee

Beverage color significantly affects perceived sensory quality and consumer preference. Although the color of coffee beans is well known to vary strongly with roast level, little work has examined how roast level and brewing conditions affect the color of the final beverage. These authors report that the color of full immersion brewed coffee is significantly affected by both roast level and brewing temperature. Coffees from three different origins were each roasted to three different levels (light, medium, and dark) and then brewed at three different temperatures (4°C, 22°C, and 92°C). Each sample was brewed toward full extraction and then diluted to precisely 2% total dissolved solids so that differences in concentration would not confound color measurements. Absorbance spectra (UV-vis) and color tristimulus values (L*a*b*) were then collected and analyzed. The authors concluded that roast level had the strongest impact on brew color, and that brew temperature had a significant impact on color for light and medium roasts, with less impact on dark roasts. Qualitatively, the cold brewed coffees tended to be redder, while the hot brewed coffees were blacker. The results suggest that there is an opportunity to manipulate and brand brewed coffee color through judicious choices of roast level and brewing temperature. Journal of Food Science. Published online ahead of print March 29, 2022. DOI: 10.11111750-3841.16089

Production of Non-Alcoholic Beer via Cold Contact Fermentation

The use of non-conventional yeasts is increasingly seen as an option for the production of low and alcohol-free beers. In this study, four non-conventional yeasts (Kazachstania servazzii, Kluyevoromyces marxianus, Pichia fermentans, and Torulaspora delbrueckii), originally isolated from sourdough cultures, were assessed by screening their ability to reduce wort aldehydes at a fermentation temperature of 1.0°C ± 0.5°C. Of the evaluated yeasts, T. delbrueckii was found to be most promising, being capable of the removal of wort-derived aldehyde off-flavors, while being sufficiently sensitive to low temperatures to limit the formation of ethanol. Despite the different alcohol by volume (0.07% vs. 0.28%), the beers produced via cold contact fermentation at 10 L scale with T. delbrueckii and a reference lager yeast strain were similar, with no major differences found after sensory analysis. The results suggest that T. delbrueckii could be used in cold contact fermentation to produce non-alcoholic beers with alcohol content at, or close to, 0%. Journal of The Institute of Brewing. 2022;128:28-35.

Sodium Reduction Strategies in Foods

In response to health concerns generated by increased sodium intake, many new approaches have been studied to reduce the sodium content in processed food. It has been suggested that reducing sodium in the food supply may be the most appropriate solution. The aim of this review was to establish what sodium reduction strategies are effective in maintaining acceptable sensory qualities for various food industry applications. Studies that evaluate and report on the effectiveness of a sodium reduction strategy relevant to food and included outcomes detailing how the strategies were received by human participants using sensory data are included, as well as book chapters, literature reviews, and patents focusing on sodium reduction strategies. Only those published in English since 1970 were included, and 277 primary studies, 27 literature reviews, 10 book chapters, and 143 patents were selected for inclusion. Data extracted included details such as analytical methods, broad and specific treatment categories, significant outcomes, and limitations, among other material. Sodium reduction methods were categorized as either salt removal, salt replacement, flavor modification, functional modification, or physical modification. Although salt removal and salt replacement were the focus of most of the studies included, future research would benefit from combining methods from other categories while investigating the impact on sensory characteristics, technological aspects, and consumer perception of the strategy. Comprehensive Reviews in Food Science and Food Safety. 2022;21:1300-1335.