This study aimed to evaluate the antioxidant, anti-inflammatory, and cytotoxic properties and phenolic composition of peel and seed of avocado varieties Hass and Fuerte using green solvents. Ethanol soluble compounds were identified in peel and seed of both varieties using HPLC-MS/MS and quantified using HPLC-DAD. Agro-industrial by-products of both varieties exhibited high radical scavenging activity against synthetic free radicals (DPPH and ABTS) and reactive oxygen species (peroxyl, superoxide, and hypochlorous acid) and high ability to reduce Fe³⁺ to Fe²⁺. The main compounds with significant contribution to the antioxidant activity determined by online HPLC-ABTS^●+ analyses were procyanidin B₂ and epicatechin in the peel and trans-5-O-caffeoyl-D-quinic acid, procyanidin B₁, catechin, and epicatechin in the seed. Peel of Fuerte significantly suppressed TNF-α and nitric oxide (NO) release (459.3 pg/mL and 8.5 μM, respectively), possibly because of the high phenolic content and antioxidant activity detected. Avocado agro-industrial by-products can be used for food and pharmaceutical purposes due to their antioxidant and anti-inflammatory properties.

Azo dyes constitute the largest and most versatile class of synthetic dyes used in the textile, pharmaceutical, food and cosmetics industries and represent major components in wastewater from these industrial dying processes. Biological decolorization of azo dyes occurs efficiently under low oxygen to anaerobic conditions. However, this process results in the formation of toxic and carcinogenic amines that are resistant to further detoxification under low oxygen conditions. Moreover, the ability to detoxify these amines under aerobic conditions is not a wide spread metabolic activity. In this study we describe the use of Brevibacterium sp. strain VN-15, isolated from an activated sludge process of a textile company, for the sequential decolorization and detoxification of the azo dyes Reactive Yellow 107 (RY107), Reactive Black 5 (RB5), Reactive Red 198 (RR198) and Direct Blue 71 (DB71). Tyrosinase activity was observed during the biotreatment process suggesting the role of this enzyme in the decolorization and degradation process, but no-activity was observed for laccase and peroxidase. Toxicity, measured using Daphnia magna, was completely eliminated.

Aquaculture in Brazil has shown expressive development since the 1990s with growth rates superior to those of cattle and poultry. In order to achieve greater productivity, intensive fish cultivation systems are employed, which can cause greater susceptibility to diseases caused by viruses, bacteria, fungi, and parasites. The reduced availability of veterinary medications approved for use in aquaculture in Brazil has lead fish farmers to the indiscriminate use of several chemical substances with antimicrobial activity, such as the dye malachite green (MG). As a result of this use, residues of MG and its main biotransformation product, leucomalachite green (LMG), may be present in fish available for consumption. The presence of residues of these compounds represents a risk to human health due to their toxicity, as well as a potential impact on the environment, and could also raise barriers for commercialization in the country and for exportation. The objective of this review is to provide the context and evidence of the use of MG in aquaculture and of its toxicological and legislative aspects. A review of the analytical methods used to determine MG residues in fish, with emphasis on mass spectrometry, is also presented.