Production of flavor compounds from olive mill waste by Rhizopus oryzae and Candida tropicalis

Abstract The purpose of this study was to investigate the production of flavor compounds from olive mill waste by microbial fermentation of Rhizopus oryzae and Candida tropicalis. Olive mill waste fermentations were performed in shake and bioreactor cultures. Production of flavor compounds from olive mill waste was followed by Gas Chromatography–Mass spectrometry, Gas chromatography- olfactometry and Spectrum Sensory Analysis ®. As a result, 1.73-log and 3.23-log cfu/mL increases were observed in the microbial populations of R. oryzae and C. tropicalis during shake cultures, respectively. C. tropicalis can produce a higher concentration of d-limonene from olive mill waste than R. oryzae in shake cultures. The concentration of d-limonene was determined as 185.56 and 249.54 µg/kg in the fermented olive mill waste by R. oryzae and C. tropicalis in shake cultures respectively. In contrast, R. oryzae can produce a higher concentration of d-limonene (87.73 µg/kg) d-limonene than C. tropicalis (11.95 µg/kg) in bioreactor cultures. Based on sensory analysis, unripe olive, wet towel, sweet aromatic, fermented aromas were determined at high intensity in olive mill waste fermented with R. oryzae meanwhile olive mill waste fermented with C. tropicalis had only a high intensity of unripe olive and oily aroma.

Composição mineral de folhas de Oliveira (Olea europaea L. ) em sistema de produção convencional / Mineral composition of olive (Olea europaea L. ) leaves in conventional production system

Objetivou-se com este trabalho quantificar a composição mineral das folhas de Oliveira a fim de diagnosticar o estado nutricional das plantas cultivadas em sistema convencional. O experimento foi conduzido com sete cultivares Arbequina, MGS Asc 315, MGS Mariense, MGS Grap 541, MGS Grap 561, Grappolo 575 e Leccino, em blocos casualizados com 4 repetições e parcelas com cinco plantas. Em maio de 2010 foram coletadas 60 folhas de cada cultivar (12 por planta) e submetidas a analise foliar. As cultivares apresentaram diferenças significativas entre si quanto aos teores foliares médios de nutrientes. Observou-se também que apesar da analise de solo apontar níveis elevados de Fe e Mn, a análise foliar acusou deficiência para esses elementos em todas as cultivares de Oliveira avaliadas. Os resultados alertam para os altos níveis de Cu, como consequência do uso abusivo de fungicidas a base de oxicloreto e calda bordalesa nos pomares. A concentração elevada desse elemento nas folhas pode causar fitotoxidez às plantas. Desta forma, sugere-se o uso racional de fertilizantes e de produtos fitossanitários no cultivo da oliveira a fim de evitar fitotoxidez ou deficiências nutricionais.

This study aimed to quantify the mineral composition of olive leaves to diagnose nutritional status of plants grown in conventional system. The experiment was conducted with seven cultivars: Arbequina, MGS Asc 315, MGS Mariense, MGS Grap 541, MGS Grap 561, Grappolo 575 and Leccino, in a randomized block design with four replications and five plants perplot. In May 2010, we collected 60 leaves for each cultivar (12 per plant),whichwere dried and subsequently analyzed. The results advert to the high levels of Cu, a consequence of the excessive use of fungicides based on copper oxychloride and Bordeaux mixture in the orchards. The high concentration of this element in the leaves can bephytotoxicity to plants and harmful to human health, since the leaves are used popularly as an aid in procedures for weight loss. Thus, we suggest the rational use of fertilizers and pesticides in the cultivation of olive trees to prevent nutritional deficiency or phytotoxicity and, if the research acknowledges the phytotherapic effect of leaves, the adoption of crops in the differentiated system of production, to obtain raw material with good quality and suitable for consumption in natura.