Yerba Mate (Ilex paraguariensis) Processing and Extraction: Retention of Bioactive Compounds.

Ilex paraguariensis is a native tree from South America known for the presence of bioactive compounds, and its processed leaves are consumed as hot and cold infusions. After harvest (step 1), the leaves are subjected to flame blanching to inactive the enzymes (step 2), followed by drying and milling (step 3). The impacts of I. paraguariensis processing on leaf composition were investigated by extracting the major compounds (chlorogenic and isochlorogenic acids (3-CQA, 4-CQA, 5-CQA, 3,4-DQA, 3,5-DQA and 4,5-DQA), p-coumaric acid, caffeine and rutin) using different ratios of ethanol and water as extraction solvent (EW 25:75, 50:50, and 75:25 (w/w)). The solvent ratio of EW 50:50 was more effective in extracting the chlorogenic acids isomers, with retention of chlorogenic acids of 3463, 9485, and 9516 µg mL- 1 for steps 1, 2, and 3, respectively. Rutin and p-coumaric acid exhibited similar behavior with the increment of processing steps; however, p-coumaric acid was only detected in steps 2 and 3 for the solvent ratios EW 50:50 and 25:50. The caffeine extraction from I. paraguariensis varied from 936 to 1170 µg mL- 1 for all processing steps, with emphasis on its concentration extracted in step 1. The evolution of processing steps led to a higher retention of phenolic compounds from I. paraguariensis, which was not observed when using different solvent ratios, and the solvent ratio EW 50:50 was more effective for the extraction of chlorogenic acids. The successful extraction of chlorogenic acids from I. paraguariensis in this study proved to be a promising alternative for the use of yerba mate beyond the cuia cup.

Bioactive Compounds from Jambolan (Syzygium cumini (L.)) Extract Concentrated by Ultra- and Nanofiltration: a Potential Natural Antioxidant for Food.

Jambolan is an unexplored fruit rich in bioactive compounds like anthocyanins, catechin, and gallic acid. Thus, the extraction of bioactive compounds allows adding value to the fruit. In this context, the present study reports the recovery and concentration of jambolan fruit extract by ultra and nanofiltration for the first time. Acidified water was used to extract polyphenols from the pulp and peel of jambolan. The extracts were concentrated using ultrafiltration and nanofiltration membranes with nominal molecular weight cut-off ranging from 180 to 4000 g mol-1. Total monomeric anthocyanin, total phenolic compounds, and antioxidant capacity were analyzed. Phenolic compounds were quantified, and anthocyanins were identified by high-performance liquid chromatography coupled to diode-array detection and mass spectrometry (HPLC-DAD-MS). Concentration factors higher than 4.0 were obtained for anthocyanins, gallic acid, and catechin after nanofiltration of the extracts. Other compounds such as epicatechin, p-Coumaric acid, and ferulic acid were quantified in the concentrated extract, and the main anthocyanins identified were 3,5-diglucoside: petunidin, malvidin, and delphinidin. Therefore, jambolan extract showed a high potential to be used as a natural dye and antioxidant in food products.

Red araçá pulp microencapsulation by hydrolyzed pinhão starch, and tara and arabic gums.

BACKGROUND: Red araçá is a Brazilian native species whose fruits are rich in phenolic acids, flavonoids, anthocyanins, and carotenoids. To preserve the properties of compounds during processing, red araçá pulp (RAP) was encapsulated by hydrolyzed pinhão starch (PS), tara gum (TG), and arabic gum (AG) in different blends in equal proportions, serving as a coating material. RESULTS: Fresh RAP had a gallic acid equivalent of 3098 mg per 100 g of dry weight, 156.29 µg ß-carotene per gram of dry weight, total anthocyanins of 18 mg per 100 g of dry weight and exhibited high antioxidant activity. The highest encapsulation efficiency achieved with the PS, TG, and AG blend was 80.4% for the total carotenoids, and that for the total anthocyanins was 76% with the TG and AG blend. Only one step of antioxidant activity degradation was identified, and the carrier system PSTG was efficient at maintaining the antioxidant activity, with half-life of 23.60-37.27 days. CONCLUSION: The use of PS alone as a coating material or associated with TG and AG gums resulted in improved retention of bioactive compounds, these being an excellent alternative coating material since they improved the stability of the antioxidant activity of RAP. © 2020 Society of Chemical Industry.

Impact of the use of saccharides in the encapsulation of Ilex paraguariensis extract.

The yerba mate (Ilex paraguariensis A.St.-Hil.) is abundant on phenolic compounds and their preservation by encapsulation can promote increased stability. The objective was to produce mate extract with a high concentration of bioactive compounds, microencapsulate and characterize them. A commercial yerba mate was used to produce the extracts and select the best extraction solvent (ethanol, water, and ethanol:water (1:1). The ethanol:water extract was encapsulated at 1:1 (w/w) by fructooligosaccharide (FOS) and gum arabic (GA), in different combinations: FOS, GA:FOS (1:3), GA:FOS (1:1), GA:FOS (3:1) and GA. The encapsulation of chlorogenic acids was around 80%, considering the major phenolic compounds by HPLC. Thermal stability, by DSC, increased at treatments FOS, GA:FOS (1:3), and GA:FOS (1:1) compare to the unencapsulated extract, and changes were noticed in ATR-FTIR bands and antioxidant activity. The encapsulated phenolic compounds from I. paraguariensis can be stable in food under heat processing.

Films based on protein isolated from croaker (Micropogonias furnieri) and palm oil.

BACKGROUND: The microstructure and the physical, mechanical, barrier and thermal properties of films based on different concentrations of protein isolated from croaker waste (CPI) and palm oil (PO) were analyzed. Films were elaborated by a casting technique using 2, 3 and 4 g CPI 100 g(-1) of a filmogenic solution and 0, 10 and 20 g of PO 100 g(-1) CPI. RESULT: Microstructure of the film surfaces of CPI with PO showed no presence of lipid droplets dispersed in the filmogenic matrix, although a rough surface was present. Films with 3% and 4% CPI and 20% PO had the lowest rates of water vapor permeability. When there was an addition of PO to the reduced tensile strength of the films, regardless of the concentration of CPI, this addition reduced the elongation of films with 3% and 4% CPI; however, it did not influence films with 2% CPI, which did not differ from the control film (0% OP). Thermal analysis revealed that films with the highest PO percentage had a lower initial weight loss when compared with other films, due to higher hydrophobicity. CONCLUSION: The use of protein isolate obtained from fish residues of low commercial value and palm oil is viable for the production of biodegradable films because the latter constitute good barrier properties and thermal stability. © 2015 Society of Chemical Industry.

Ozone oxidation of cassava starch in aqueous solution at different pH.

Ozone is a more powerful oxidant than common oxidising agents, such as sodium hypochlorite and hydrogen peroxide. It is considered as a safer starch modification method for both consumers and the environment. However, few studies have investigated the changes in starch properties associated with ozone treatment, particularly when applied in aqueous solution. This work aimed to evaluate the carbonyl and carboxyl contents, the X-ray diffraction patterns, the spectrum profiles of Fourier transform infrared spectroscopy, the pasting properties and the surface morphology of ozone-oxidised cassava starch during 60 min under different pH (3.5, 6.5 and 9.5) at 25°C. The pH 6.5 and 9.5 seemed to favour the cross-linking between the depolymerised starch molecules during ozonation. The pH 3.5 was more effective in reducing the peak viscosity, breakdown, setback and final viscosity of cassava starch during ozonation in aqueous solution. No differences in the granule surface morphology were observed in the ozone-treated cassava starches compared to native starch.

Development of oxidised and heat-moisture treated potato starch film.

This study investigated the effects of sodium hypochlorite oxidation and a heat-moisture treatment of potato starch on the physicochemical, pasting and textural properties of potato starches in addition to the water vapour permeability (WVP) and mechanical properties of potato starch films produced from these starches. The carbonyl contents, carboxyl contents, swelling power, solubility, pasting properties and gel texture of the native, oxidised and heat-moisture treated (HMT) starches were evaluated. The films made of native, oxidised and HMT starches were characterised by thickness, water solubility, colour, opacity, mechanical properties and WVP. The oxidised and HMT starches had lower viscosity and swelling power compared to the native starch. The films produced from oxidised potato starch had decreased solubility, elongation and WVP values in addition to increased tensile strength compared to the native starch films. The HMT starch increased the tensile strength and WVP of the starch films compared to the native starch.