engleski

Stability of olive leaf drink upon storage at different temperatures

n the olive oil production, olive leaves mostly often remain insufficiently used and represent waste, although many studies showed its anticancer, antiinflammatory and antimicrobial properties due to abundance of polyphenols, which makes olive leaves potential ingredient for functional food production. Also, olive leaf drink due to it valuable composition represents functional drink itself. But, functional properties can reduce due to polyphenols degradation, especially during storage. Hence, this research aimed to investigate the stability of olive leaf drink during nine weeks storage at different temperatures (8, 22 and 32 °C). Influence of storage time and storage temperature was monitored by analysis of total phenols, antioxidant capacity by DPPH, color parameters (L*, a*, b*, , BI) and sensory properties of olive leaf drink samples. Obtained results showed that total phenols slightly decreased during storage, being most stabile on 8 °C. Antioxidant capacity showed approximately similar trend. Color of all samples darkened by the storage with increase rate of L*, and BI related to temperature increase. Major color changes were observed by the storage ending at 32 °C. Sensory analysis confirmed change of olive leaf drink color, where yellowness decreased as brownness increased by the storage time and temperature. Odor and flavor decreased with time and at higher storage temperatures. Intensity of drink's main taste attributes (astringent and bitter taste) decreased by storage time, especially on higher temperatures, resulting with higher scored harmony taste. Obtained results showed good stability of olive leaf drink, suggesting its potential as a functional product or semi-product.

olive leaf, storage, phenols, color, sensory

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