Changes in chemical and microbiological composition of two varieties of olive during fermentation

Autor: Y. Erdek, I. Alperden, E. Özsan, Mehlika Borcakli, Güner Özay
Rok vydání: 1993
Předmět:
Zdroj: Grasas y Aceites, Vol 44, Iss 4-5, Pp 253-258 (1993)
Grasas y Aceites; Vol. 44 No. 4-5 (1993); 253-258
Grasas y Aceites; Vol. 44 Núm. 4-5 (1993); 253-258
Grasas y Aceites
Consejo Superior de Investigaciones Científicas (CSIC)
ISSN: 1988-4214
0017-3495
DOI: 10.3989/gya.1993.v44.i4-5.1075
Popis: In this study, the changes in chemical and microbiological composition of two olive varieties, Edincik and Gemlik, have been examined during fermentation at industrial scale. Prior to processing, the olives have been thoroughly characterized chemically and microbiologically. Then, the nature of the fermentation process has been investigated during the 9 months of fermentation period by taking samples at certain intervals. The most important characteristics of the two varieties before processing were determined as follows: Edincik variety was found to have relatively higher reducing sugar (5.94%) and moisture (59.53%) contents than that of Gemlik variety (4.45% reducing sugar and 43.18% moisture). Polyphenol concentrations of two varieties were 2.50% and 2.40%, respectively. During fermentation, reducing sugar and polyphenols contents were decreased gradually in the fruit, while other constituents were slightly changed or remained almost unchanged. While reducing sugar decreased to the values of 0.98% and 0.65%, free acidity in brine increased to 0.41% and 0.35%, pH value of brine were 4.4 and 4.9 and salt content in fruit were reached to the final values of 7.4% and 6.9% for Edincik and Gemlik varieties, respectively. Microflora of the raw samples was consisted of various bacteria mainly, lactobacilli, Gram-negative, anaerobic sulfide producing, coliform bacteria and yeasts. During the fermentation of both varieties, yeasts were dominated starting from the 40th days of fermentation.En este estudio, se han examinado los cambios en la composición química y microbiológica de dos variedades de aceituna, Edincik y Gemlik, durante la fermentación a escala industrial. Las aceitunas se caracterizaron química y microbiológicamente antes del tratamiento. Posteriormente, la naturaleza del proceso se investigó durante ios nueve meses del periodo de fermentación tomando muestras cada ciertos intervalos. Se determinaron las características más importantes de las dos variedades antes del tratamiento: la variedad Edincik tuvo un mayor contenido relativo en azúcares reductores (5.94%) y humedad (59.53%) que la variedad Gemlik (4.45% azúcares reductores y 43,18% humedad). Las concentraciones de polifenoles de las dos variedades fueron 2.50% y 2.40% respectivamente. Durante la fermentación, los contenidos en azúcares reductores y polifenoles disminuyeron gradualmente en el fruto, mientras que otros constituyentes cambiaron ligeramente o permanecieron casi inalterados. En la salmuera los azúcares reductores disminuyeron hasta valores de 0.98% y 0.65%, aumentando la acidez libre hasta 0.41 % y 0.35%, con unos valores de pH de 4.4 y 4.9, alcanzando el contenido en sal en el fruto valores finales de 7.4% y 6.9% para las variedades Edincik y Gemlik respectivamente. La microflora de las muestras originales estuvo constituida por bacterias, principalmente del tipo: lactobacitos, Gram-negativo, anaerobios productores de sulfuro, bacterias coliformes y hongos. Durante la fermentación de ambas variedades, los hongos fueron controlados a los 40 días de fermentación.
Databáze: OpenAIRE
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