Acerola byproduct

The step-by-step procedure for preparing the kombucha-like beverage using acerola byproduct as a raw material, as detailed in the study, involves the following key steps:

Preparation#

Acerola Byproduct Preparation#

The acerola byproduct obtained from the juice clarification step is dried, milled, and subjected to hydrothermal extraction at concentrations of 1%, 3%, and 5% (w/v on a dry basis) to yield extracts with varied total phenolic content.

Inoculum Preparation#

The starter culture or SCOBY is obtained and maintained in sugared green tea. The inoculum is prepared by infusing green tea, adding glucose, fructose, liquid broth, and biofilm from the mother kombucha.

Fermentation Process#

Mix acerola extracts with glucose-fructose substrate and inoculum. Prepare samples with 1%, 3%, and 5% acerola byproduct concentrations and ferment for 15 days at 30°C. Monitor pH, sugar consumption, total phenolic content, and products (ethanol, acetic acid, and cellulose) during fermentation.

Characterization#

Measure pH values during fermentation. Determine concentrations of sugars (glucose and fructose), acetic acid, ethanol using High-Performance Liquid Chromatography (HPLC). Evaluate total phenolic content, antioxidant activity, vitamin C content. Conduct microbiological analysis for yeast and acetic acid bacteria counts. Purify cellulose samples for characterization.

Results and Discussion#

Analyze the kinetic profile of pH reduction during fermentation. Assess the production of ethanol, acetic acid, bacterial cellulose, total phenolic content, antioxidant activity, and vitamin C content. Characterize the physicochemical and morphological structures of bacterial cellulose.

Analytical results#

Ethanol#

The final concentration of ethanol in all samples was approximately 9.5 g/L, achieved at different fermentation durations: 12 days for 1% acerola byproduct, 9 days for 3%, and 6 days for 5%.

Acetic Acid#

The highest production of acetic acid was observed with 5% acerola byproduct, reaching a concentration of 16.3 g/L.

Bacterial Cellulose#

The highest production of bacterial cellulose was also achieved with 5% acerola byproduct, with a concentration of 4.0 g/L. The membranes obtained were less porous and denser, with a highly crystalline structure (96.4%), indicating enhanced production in the presence of higher amounts of acerola byproduct.

Health benefits#

The study highlighted potential positive health benefits of the fermented beverage preparation. The evidence found in the study includes:

Antioxidant Properties#

The kombucha-like beverage showed an increase in total phenolic content during fermentation, potentially enhancing its antioxidant activity. This could contribute to reducing oxidative stress and promoting health benefits.

Immune-Boosting Potential#

The presence of polyphenolic compounds in acerola byproduct, which contribute to high antioxidant activity, implies that the beverage may help boost the human immune response, offering health-promoting properties similar to traditional kombucha.

Functional Properties Enhancement#

Incorporating acerola byproduct in the fermentation process could lead to the development of a beverage with novel functional properties due to its antioxidant-rich nature. This may result in a product with enhanced health benefits beyond traditional kombucha.

These findings suggest that the kombucha-like beverage made with acerola byproduct could offer positive health effects, potentially enhancing antioxidant properties, immune response, and overall well-being.

Reference#

Leonarski, E., Cesca, K., Zanella, E., Stambuk, B. U., de Oliveira, D., & Poletto, P. (2021). Production of kombucha-like beverage and bacterial cellulose by acerola byproduct as raw material. LWT - Food Science and Technology, 135, 110075. DOI: 10.1016/j.lwt.2020.110075