Volatile profile of cashew apple juice fibers from different production steps.

This study aimed to determine the volatile profile of cashew apple fibers to verify which compounds are still present after successive washings and thus might be responsible for the undesirable remaining cashew-like aroma present in this co-product, which is used to formulate food products like vegetarian burgers and cereal bars. Fibers were obtained from cashew apple juice processing and washed five times in an expeller press. Compounds were analyzed by the headspace solid-phase micro extraction technique (HS-SPME) and gas chromatography-mass spectrometry (GC-MS), using a DB-5 column. Sensory analysis was also performed to compare the intensity of the cashew-like aroma of the fibers with the original juice. Altogether, 80 compounds were detected, being esters and terpenes the major chemical classes. Among the identified substances, 14 were classified as odoriferous in the literature, constituting the matrix used in the Principal Component Analysis (PCA). Odoriferous esters were substantially reduced, but many compounds were extracted by the strength used in the expeller press and remained until the last wash. Among them are the odoriferous compounds ethyl octanoate, γ-dodecalactone, (E)-2-decenal, copaene, and caryophyllene that may contribute for the mild but still perceptible cashew apple aroma in the fibers that have been pressed and washed five times. Development of a deodorization process should include reduction of pressing force and stop at the second wash, to save water and energy, thus reducing operational costs and contributing to process sustainability.

Antimicrobial activities of components of the glandular secretions of leaf cutting ants of the genus Atta.

The secretions of the mandibular and metapleural glands of leaf cutting ants contain antimicrobial substances that protect the mutualistic fungal colony within the nest from attack by parasitic micro-organisms. The major constituents of these secretions (citral, 4-methyl-3-heptanol, 2-heptanone, 3-octanone, 4-methyl-2-heptanone, beta-citronellol, geraniol, phenylacetic, indolacetic, hexanoic and octanoic acids were tested against resistant strains of the human pathogens, Escherichia coli, Staphylococcus aureus and Candida albicans. Assays were carried out using filter paper discs impregnated with either hexane or water solutions of the analytes in the concentration range 250-6,000 ng/microl. Although most of the tested compounds presented strong antibacterial and antifungal activities, citral, geraniol, 4-methyl-3-heptanol, hexanoic and octanoic acids were the most effective, particularly against C. albicans. The results suggest that these compounds may be of potential value as antibiotics in the treatment of human candidiasis.