Composition, structure, and valorisation of fibres from olive fruit and by products
Dietary fibres (DF) are highly complex substances that can be described as carbohydrates (cellulose, hemicellulose and pectin), lignins and associated substances that resist to digestion by human alimentary enzymes. There is an abundance of scientific evidence regarding the beneficial effects of DF, as they play a significant role in several physiological processes and in the prevention of several diseases, such as metabolic syndrome and different types of cancers by the normalization of blood lipids, and the regulation of glucose absorption and insulin secretion…). DF could play an important role in the prevention of diabetes. Some dietary fibres (soluble fibres as guar gum and β-glucan) may improve glycemic control by reducing the rate of glucose absorption which resulted in decreasing glycemia and hence decreasing insulin secretion; or by modulating gut hormones such as gastric inhibitory polypeptide and glucagon-like peptide (1). The importance of fibres has led to the appearance of products named as fibre-enriched food and gelling agents. Olive fruit contains a considerable amount of fibres with promising functional properties, such as better gel formation and water holding capacity. During olive oil processing, two by-products are obtained: olive pomace, and olive mill wastewater (OMWW). The last is known for its environmental concerns related to the pollution of water, alteration in soil and toxicity for bacteria, plants and animals. However, it can also contains high amounts of dietary fibres as pectin material, which could be recovered from OMWW. The purpose of this mini-review was to discuss the composition and structural characterization of dietary fibres in olives (fruit and olive oil by-products) related to their potential applications as an interesting valorisation option.
The growing demand by consumers for healthier products has been stimulated by the research on beneficial and functional compounds recovered from natural products. The importance of dietary fibres (DF) has been emphasized by numerous authors during the recent years (1, 2, 3). These studies showed that DF are important components in our diet, and they can provide beneficial effects on our health for example by contributing to the prevention, reduction and treatment of certain cancers (colorectal and breast cancer), cardiovascular diseases, diabetes and obesity (4-7, 8). DF is a plant-derived material resistant to the digestion by human alimentary enzymes (9). They can include cell wall components (cellulose, hemicellulose, lignin and pectin), non-stru