French Guiana honeys from the Amazon biome: First description of volatile fraction and antioxidant capacity

Various honeys from French Guiana were collected and analyzed to investigate their volatile fraction composition and antioxidant activity. Volatile composition was assessed using HS-SPME/GC, GC-MS technique. Oxygenated monoterpenes like hotrienol (0.5-45.3%) were found as major molecules, followed by non terpenic compounds like phenylacetaldehyde (0.8-18.2%) or 3-hydroxy-4-phenyl-2-butanone (0.1-29.3%). Three chemical groups using statistical analysis were classified within investigated honey samples: norisoprenoids/shikimates, mevalonate and their combination. Total phenolics content (TPC) was determined by Folin-Ciocalteu method. Antioxidant activity was assessed by oxygen radical absorbance capacity (ORAC) and 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) assays. TPC and anti-radical activity were compared with multifloral honeys from neighboring regions, indicating the possible presence of compounds from the polyphenol family. These results are promising for further biological studies involving honeys from French Guiana.

Recent advances and trends in extraction techniques to recover polyphenols compounds from apple by-products

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Apple by-products are a source of phenolic compounds associated with bioactivities.

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Apple processing industries generate by-products that could be better used.

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This work provides an up-to-date literature overview on extraction techniques.

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Gaps and future trends related to apple by-products are critically presented.

Apple is one of the most consumed fruits worldwide and has recognized nutritional properties. Besides being consumed fresh, it is the raw material for several food products, whose production chain generates a considerable amount of by-products that currently have an underestimated use. These by-products are a rich source of chemical compounds with several potential applications. Therefore, new ambitious platforms focused on reusing are needed, targeting a process chain that achieves well-defined products and mitigates waste generation. This review covers an essential part of the apple by-products reuse chain. The apple composition regarding phenolic compounds subclasses is addressed and related to biological activities. The extraction processes to recover apple biocompounds have been revised, and an up-to-date overview of the scientific literature on conventional and emerging extraction techniques adopted over the past decade is reported. Finally, gaps and future trends related to the management of apple by-products are critically presented.

Edible flowers from Theobroma speciosum: Aqueous extract rich in antioxidant compounds

Theobroma speciosum, known as "cacauí" in Brazil, is considered a prominent unconventional food plant. The objective of this work was to evaluate the chemical profiles, antioxidant capacity and minerals of the aqueous extract and fractions from its flowers. The identified compounds were sugars, organic acids and phenolics compounds such as citric, malic and protocatechuic acids, quercetin, quercetin pentoside and quercetin-3-O-glucoside. The extract was rich in phenolic compounds (640 mg GAE g^-1). Furthermore, fractions also presented phenolic compounds from 170.7 to 560.7 mg GAE g^-1 (mainly protocatechuic acid, quercetin and derivatives), which influenced on the high antioxidant capacity in DPPH, ABTS, FRAP and co-oxidation β-carotene/linolenic acid assays. Flowers presented potassium (115 ± 2 μg mL^-1), magnesium (18.4 ± 0.2 μg mL^-1), phosphorus (7.0 ± 0.0 μg mL^-1) and calcium (3.1 ± 0.1 μg mL^-1). Moreover, the flowers aqueous extract represents a new promising food source rich in antioxidant compounds.

Germination in Optimal Conditions as Effective Strategy to Improve Nutritional and Nutraceutical Value of Underutilized Mexican Blue Maize Seeds

Germination of grains is a bioprocess of emerging interest to improve nutritional and nutraceutical profile of cereals in a natural way. The aim of this work was to identify optimal germination conditions (temperature/duration) for producing a functional blue maize flour with maximum values of protein content (PC), antioxidant activity (AoxA), and total phenolic and anthocyanin contents (TPC, TAC). A central composite rotatable experimental design (response surface methodology) with two factors [Germination temperature (Gtemp, 20-40 °C) / Germination duration (Gdur, 12-220 h)] in five levels was used (13 treatments). Blue maize seeds were soaked in distilled water (25 °C / 12 h) before germination. The sprouts were dried, tempered (25 °C), and ground to obtain germinated blue maize flours (GBMF). The prediction models developed for each response variable showed high coefficients of determination, demonstrating their adequacy to explain the variations in experimental data. Maximum values of PC, AoxA, TPC, and TAC were attained at Gtemp = 26.9 °C / Gdur = 207.7 h. Optimized germinated blue maize flour (OGBMF) presented higher PC (+38.48%), AoxA (ABTS: +192%, ORAC: +160%, DPPH: +148%), TPC (+79%), and TAC (+9.9%) than unprocessed blue maize flour (UBMF). Germination at optimal conditions is an effective strategy to increase the nutritional/nutraceutical quality of blue maize seeds, thus the flour of these germinated seeds could be used for the development of functional foods.