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ARS Home » Pacific West Area » Albany, California » Western Regional Research Center » Healthy Processed Foods Research » Research » Publications at this Location » Publication #385714

Research Project: New Sustainable Processes, Preservation Technologies, and Product Concepts for Specialty Crops and Their Co-Products

Location: Healthy Processed Foods Research

Title: Health benefits of first and second extraction drum-dried pitted olive pomace

item INZUNZA-SOTO, MARCE - Autonomous University Of Sinaloa
item Thai, Thanh Thao S
item Sinrod, Amanda
item Olson, Donald
item Avena Bustillos, Roberto
item LI, XUEQI - University Of California, Davis
item ROLSTON, MATTHEW - University Of California, Davis
item WANG, SELINA - University Of California, Davis
item TERAN-CABANILLAS, ELI - Autonomous University Of Sinaloa
item Yokoyama, Wallace - Wally
item McHugh, Tara

Submitted to: Journal of Food Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/3/2021
Publication Date: 10/12/2021
Citation: Inzunza-Soto, M., Thai, T.T., Sinrod, A., Olson, D.A., Avena Bustillos, R.D., Li, X., Rolston, M.R., Wang, S.C., Teran-Cabanillas, E., Yokoyama, W.H., McHugh, T.H. 2021. Health benefits of first and second extraction drum-dried pitted olive pomace. Journal of Food Science. 86(11):4865-4876.

Interpretive Summary: Olive pomace (OP) is the main by-product (80% of olive fruit) in olive oil production. OP is mainly composed of pigments, fatty acids, proteins, phenolic compounds, and dietary fiber. The main functional property of OP is related to its high polyphenol content. Hydroxytyrosol is considered the main phenolic compound of OP (54%). This molecule has been associated with various antioxidant activities, antimicrobial, anti-inflammatory and anti-tumor properties, as well as beneficial effects on neurovascular, cardiovascular, and metabolic diseases, that have been demonstrated in animal and human studies. The development of foods rich in bioactive compounds such as fiber and phenolic compounds has become a novel trend in the food industry. The addition of common foods with olive byproduct compounds can improve the nutritional profile of products or the stability of food matrices and contribute to the health benefit of consumers. The objective of this study was to evaluate relevant nutritional and health benefits of drum-dried pitted olive pomaces obtained after first and second olive oil extraction with high phenolics and dietary fiber.

Technical Abstract: Main byproduct of olive oil extraction is pomace (OP) consisting of pulp, skins and pits. OP is used as feed for cows and other farm animals. After pits and skin removal, there is the possibility of using OP pulp as additive for human foods as it is rich in dietary fiber and contains high concentrations of phenolics with high antioxidant capacity compared to fruits and vegetables. This study evaluated mice health benefits of drum-dried pitted OP with high phenolics and dietary fiber, obtained after first and second oil extraction. Fresh OP was steam blanched, then pits and skins separated in a pulper/finisher, and pulp drum-dried and milled. First and second extraction OP were characterized by proximate analysis, total soluble phenolics (TSP), individual phenolics, soluble and insoluble fiber, and water activity. Also, drum-dried pitted OP from first and second extraction was formulated at 10% and 20% in a high fat diet to feed mice. A low fat (5%) and high fat (18%) diets were also used for comparison. First extraction OP has higher TSP than OP from second extraction. Hydroxytyrasol was the main phenolic in both OP. Mice weight gain was lower for the four OP diets compared to high and low-fat control diets. Fecal protein was high for all 4 OP diets, indicating poor protein retention in mice, possibly by phenolics protein and enzymes binding. Liver weight and adipose tissue were lower in mice consuming the four high fat OP diets compared to high fat control diet. Also, there was no effect on blood glucose by OP in diets as indicators of health benefits. Mice feces gut microbiota analysis indicated that Actinobacteria phylum decreased in the OP diets compared to the two control diets while Bacteroidetes phylum increased, indicating both a positive correlation with reduced body fat and weight. Drum-dried pitted OP is a novel agricultural byproduct with potential of its bioactive compounds to be incorporated in feeds and foods, providing health benefits.