Efficient Anthocyanin Recovery from Black Bean Hulls Using Eutectic Mixtures: A Sustainable Approach for Natural Dye Development.

There is a growing interest in exploring new natural sources of colorants. This study aimed to extract anthocyanins from broken black bean hulls (Phaseolus vulgaris L.) by modifying water with a eutectic mixture (choline chloride:citric acid (ChCl:Ca)). Ultrasound-assisted extraction (UAE) was employed and optimized in terms of temperature (30-70 °C), ultrasound power (150-450 W), and eutectic mixture concentration in water (1-9% (w/v)), resulting in an optimal condition of 66 °C, 420 W, and 8.2% (w/v), respectively. The main quantified anthocyanins were delphinidin-3-O-glycoside, petunidin-3-O-glycoside, and malvidin-3-O-glycoside. The half-life of the anthocyanins at 60 °C increased twelvefold in the eutectic mixture extract compared to the control, and when exposed to light, the half-life was 10 times longer, indicating greater resistance of anthocyanins in the extracted eutectic mixture. Additionally, the extracts were concentrated through centrifuge-assisted cryoconcentration, with the initial cycle almost double the extract value, making this result more favorable regarding green metrics. The first concentration cycle, which showed vibrant colors of anthocyanins, was selected to analyze the color change at different pH levels. In general, the technology that uses eutectic mixtures as water modifiers followed by cryoconcentration proved to be efficient for use as indicators in packaging, both in quantity and quality of anthocyanins.

Bioactive compounds recovered from apple pomace as ingredient in cider processing: monitoring of compounds during fermentation.

The apple pomace-industrial residue of apple beverages manufacture-presents 42-58% of the phenolic content of fresh fruit. As the phenolic composition influences the quality of ciders, it is very relevant to monitor the evolution of these compounds during the industrial process. Therefore, this research aim was to monitor the cider composition with the addition of phenolic extract from apple pomace during the fermentation. Two treatments, S1 (without extract) and S2 (with added extract), were evaluated during 15 days of fermentation. After 15 fermentation days, the sample S2 presented an increase of 23% in total phenolic compounds and 40% in flavonoids without harm to the fermentation kinetics. Concerning the evolution of monomeric phenolic compounds, the phenolic acids in S1 and S2 presented a similar trend during the fermentation period. Enzymatic hydrolysis reactions resulted in the chlorogenic acid content decreasing, in line with increased levels of caffeic acid. Phloridzin and quercetin glycosides content showed the greatest increase in S2. The final product S2 presented higher antioxidant activity and some sensorial characteristics (astringency, bitterness and colour) were accentuated. This work shows that phenolic compounds added were maintained during the process and it did not prejudice the fermentation reactions. Therefore, this is a good alternative to valorize apple pomace and improve the functional and sensorial quality of the cider.

Pressurized aqueous solutions of deep eutectic solvent (DES): A green emergent extraction of anthocyanins from a Brazilian berry processing by-product.

Deep eutectic solvents (DES) are emergent solvents with high extractability of bioactive compounds. Therefore, anthocyanin rich-fractions were recovered from jaboticaba peels by combining aqueous solutions of DES and pressurized liquid extraction (PLE). The extraction occurred at 10 MPa, 12 min, with conditions optimized through response surface methodology: 47% DES concentration, 90 °C, and 5.3 mL/min flow rate. PLE with different DES (choline chloride combined with propylene glycol or malic acid) solutions were compared to conventional solvents (water and acidified water) concerning yield, thermostability, antioxidant, anti-diabetic, and anti-obesity activities. DES solutions presented anthocyanin yields up to 50% higher than conventional solvents. ChCl:Ma, with the highest anthocyanin stability ( E a  = 77.5 kJ.mol-1), was a promising solvent concerning color, anti-diabetic and anti-obesity potential. Environmental analysis by Green Certificate and EcoScale indicated PLE with DES solutions is a green and efficient approach to recover anthocyanin from jaboticaba peel, providing useful extracts.

Effect of cryoconcentration process on phenolic compounds and antioxidant activity in apple juice.

BACKGROUND: Freeze concentration is an alternative process where bioactive compounds are preserved during the processing of juice concentrates. This study proposed a simple and cheaper cryoconcentration process assisted by centrifugation in apple juice. RESULTS: The levels of phenolics increased significantly (P < 0.05) with each freeze concentration cycle that was performed. Furthermore, the process resulted in an average increase in the concentration of phenolics of 1.9, 2.9 and 3.8 times for the first, second and third steps of the concentration, respectively. In relation to phenolics, the antioxidant potential, which was evaluated by radical scavenging activity and reduction power, also increased with the cryoconcentration steps. The influence of the phenolics on the in vitro antioxidant activity was confirmed by a significant correlation between the antioxidant assays and total phenolics, flavonoids, flavan-3-ols, and flavonols (r > 0.70). CONCLUSION: The increase in antioxidant activity may have been attributed to the increase in the phenolic compounds in the apple juices because of the cryoconcentration process. Therefore, this could be an excellent natural product to supplement and enrich blends, juices, ciders, smoothies, and jams in order to improve the sensorial, nutritional and antioxidant properties. © 2018 Society of Chemical Industry.

Quality assessment of white mold-ripened cheeses manufactured with different lactic cultures.

BACKGROUND: White mold-ripened cheeses were investigated with the objective of proposing a colorimetric method to monitor the surface growth of Penicillium candidum and to evaluate the influence of the mesophilic (homofermentative (QMO) and heterofermentative (QMLD)) and thermophilic (QT) starter cultures on the physicochemical composition and sensory description. RESULTS: The whiteness index was effective in proving the appearance of superficial mycelium and the stability of white mold growth. The lactic cultures showed significant influence on most of the physicochemical analyses. The cheese made with thermophilic lactic culture had a 1 day gain in the growth of mycelium on the surface; nevertheless, the appearance of this product was potentially not acceptable for consumers. The heterofermentative mesophilic cheese had a better appearance and texture profile. However, the homofermentative mesophilic cheese showed aspects of fresh cheese and was acceptable for a wide range of consumers. CONCLUSION: The whiteness index was efficient to monitor the surface growth of P. candidum. The highest proteolytic effect was found in the QMLD and QT cultures. However, the cheese elaborated with the QMLD culture showed the best sensory acceptance. © 2015 Society of Chemical Industry.