Effect of fermentation on the physicochemical characteristics and sensory quality of Arabica coffee.

This work aims to assess the physicochemical characteristics and final sensory quality of Yellow Catuai IAC 62 Arabica coffee fermented with Saccharomyces cerevisiae. For such a purpose, a Composite Central Rotational Design (CCRD) was performed to investigate how fermentation time,temperature and pH conditions, moisture content and concentration of sugars and organic acids affect its sensory quality on two different roast levels in accordance with Specialty Coffee Association (SCA) protocols. It was found that fructose concentration decreased from 12 g/L to around 5 g/L during fermentation, regardless of temperature condition. Furthermore, longer fermentation times and higher temperatures have lowered sucrose and glucose concentrations from 4 to 2 g/L and 7 g/L to zero, respectively. Glycerol concentration was higher as time and temperature increased, and optimal conditions ranged at temperatures between 24 °C and 32 °C from 35 to 45 h of fermentation time. pH decreased as fermentation time elapsed, but there was a more significant reduction due to higher temperatures, starting at around pH 5 and, lower than 4 under extreme conditions. Contents of organic acids such as acetic, propionic, succinic, and lactic acids, were measured at the final stage of each fermentation process under studied conditions. It was observed that coffee samples achieved final scores ranging from 81 to 85 (SCA score), even in longer times and extreme temperature conditions, thus all samples have been classified as specialty coffees. This work described the initial step towards parameterizing fermentation processes, given that the response variables of temperature and fermentation time, were optimal and enhanced the sensory quality of coffee as beverage. Saccharomyces cerevisiae, a commercial product which has already been made available for producers, can ensure an increase in the sensory quality of coffee.

Characterization of quail egg powders obtained by liquid egg drying and foam-mat drying.

BACKGROUND: Quail eggs have nutritional, therapeutic, and functional potential but are still not widely consumed globally. Their availability in powder form can contribute to expanding their consumption worldwide. However, drying can significantly affect their properties. To the best of our knowledge, there is no study comparing the effect of drying methods on the rehydration capacity and functional properties of whole quail egg powder. In this context, this work aimed to obtain powdered quail eggs by convective oven drying and freeze drying of eggs in liquid and foam form, to evaluate the effect of each drying method on their physical, rehydration, and functional characteristics. RESULTS: The powder obtained by freeze-drying eggs in the liquid form (L-FD) showed the most desirable foaming capabilities; however, it produced less stable emulsions. The powder obtained by convective oven drying of eggs in liquid form (L-CONV) had the worst rehydration and foaming capabilities but produced firmer gels and had good emulsifying capacity. Finally, the powders obtained by foam-mat drying yielded very stable foams and emulsions. CONCLUSION: The methods for quail egg powder production that were evaluated performed well. The results point to the strong potential of quail egg powder as an ingredient. Liquid freeze-dried (L-FD) eggs stood out for their rehydration capacity. Each powder had different functional properties, so the choice of the best method depends on the intended application of the powder as specific characteristics and functional properties are suitable for preparing each food. © 2022 Society of Chemical Industry.

Evaluation of the microencapsulation process of conidia of Trichoderma asperellum by spray drying.

Microencapsulation of microorganisms has been studied to increase product shelf life and stability to enable the application in sustainable agriculture. In this study, the microencapsulation of Trichoderma asperellum conidia by spray drying (SD) was evaluated. The objective was to assess the effect of drying air temperature and wall material (maltodextrin DE20, MD20) concentration on the microencapsulation and to identify the optimum conditions to produce, in high yield, microparticles with low moisture, high conidial viability and conidial survival. Microparticles were characterized in terms of morphology, particle size, and shelf life. A central composite rotatable design (CCRD) was used to evaluate the effect of operating parameters on drying yield (DY), moisture content, conidial viability (CV), and conidial survival (SP). Microencapsulation experiments were carried out under optimum conditions to validate the obtained model. The optimum temperature and MD20/conidia dry weight ratios were 80 °C and 1:4.5, respectively, which afforded a drying yield of 63.85 ± 0.86%, moisture content of 4.92 ± 0.07%, conidial viability of 87.10 ± 1.16%, and conidial survival of 85.78 ± 2.88%. Microencapsulation by spray drying using MD20 as wall material extended the viability of conidia stored at 29 °C compared with the control. The mathematical models accurately predicted all the variables studied, and the association of the microencapsulation technique using DE20 maltodextrin was able to optimize the process and increase the product's shelf life. It was also concluded that high inlet air temperatures negatively affected conidia survival, especially above 100 °C.