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Spirulina is a highly nutritious microalgae commonly used as a food additive. During fermentation, different adjuncts are incorporated to act as a nutrient source for yeast and fortify or modify the sensory attributes of the final product. In this study, the effect of Spirulina on the characteristics of controlled yeast fermentation and the production of volatile organic compounds (VOCs) was analyzed. Spirulina was added to malted barley during mashing and fermented under standard conditions. An unaltered mash (negative control) and yeast extract (positive control) were also fermented. The addition of Spirulina resulted in an increased fermentation rate (~14% faster) and bigger yeast cells (~34% larger) in comparison to the negative control. There were differences in color (determined as SRM) between treatments; however, there were only minor differences in VOCs, with no statistical differences observed between chemical compound groups. No differences were observed in the pH, total number of yeast cells, or final attenuation between treatments. The primary mechanism for the observed differences is believed to be an increase in amino acids available to yeast that were contributed by the Spirulina. This shows both that Spirulina has a high potential as a fermentation adjunct and that the amino acid profile of an adjunct can significantly impact fermentation. [ABSTRACT FROM AUTHOR]

ABSTRACT Hibiscus beverage was treated with dense phase carbon dioxide (DPCD), and inactivation was determined using yeasts and molds (Y&M) and aerobic plate counts (APCs). A central composite design with pressure (13.8-34.5 MPa) and residence time (5-8 min) at constant temperature (40C) and %CO2 was used. A storage study (14 weeks at 4C) included the DPCD treated (34.5 MPa, 8% CO2, 6.5 min and 40C), thermal treated (HTST) (75C for 15 s) and untreated (control) beverages monitoring microbial growth, pH, °Brix, titratable acidity (TA) and color. A minimum of 5 and 0.85 log reductions for Y&M and APC was achieved for all DPCD treatments. APC remained ∼2 logs during the 14 weeks of storage, while Y&M were reduced ∼3 logs and remained stable for both DPCD and HTST samples. °Brix and pH were not affected by DPCD treatment, whereas TA increased. A slight decrease was observed for a*, b*, hue angle and chroma for all treatments. Overall results showed that DPCD can be competitive with HTST process producing a shelf stable product while minimally affecting its physicochemical attributes. PRACTICAL APPLICATIONS Hibiscus beverage processing requires an extraction step followed by a preservation method. New processing technologies such as dense phase carbon dioxide require little to no heat and may help to maintain the fresh-like color, flavor and nutrients of the beverage. This research pursues the optimal processing conditions for a hibiscus beverage by comparing dense phase carbon dioxide processing with traditional pasteurization, and following the microbial stability and physicochemical attributes of these beverages after processing and during storage. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the impact of temperature on the potential extraction of bioactive compounds from aqueous hop extract samples. The main bioactive components were characterised and analysed by LC-MS/MS, FT-IR, phenolic compounds and total flavonoids. Antifungal activity was evaluated in vitro and in vivo in bell peppers. LC-MS/MS analysis demonstrated increases and decreases of bioactive compounds in both extracts depending on the extraction temperature of 25 or 65 °C. The bioactive compounds showed significant changes in the bands between 2786 to 3600 cm -1 and 1022 to 1729 cm -1 in the FT-IR spectrum. The highest antifungal activity against the microorganisms was observed in the Ekuanot MT extract at an extraction temperature of 65 °C. The in vivo test with bell peppers presented antifungal activity during five days of evaluation under normal environmental conditions without refrigeration, presenting ≤ 52% of the disease due to F. oxysporum and A. solani .