Health benefits of first and second extraction drum‐dried pitted olive pomace

Abstract

Olive pomace (OP) is the main by‐product of olive oil extraction. After pit and skin removal, OP pulp has high concentrations of dietary fiber and phenolics with high antioxidant capacity. This study evaluated mice health benefits of drum‐dried pitted OP pulp 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. OP was characterized by proximate analysis, total soluble phenolics (TSP), individual phenolics, and dietary fiber. Drum‐dried pitted OP from first and second extraction was formulated at 10% and 20% in a high fat mice diet. Low fat (5%) and high fat (18%) control diets were also used for comparison. First extraction OP had higher TSP than OP from second extraction. Hydroxytyrosol was the main phenolic in 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 OP diets, indicating poor protein retention in mice, possibly by phenolics binding of protein and enzymes. 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. Mice gut microbiota analysis indicated that Actinobacteria decreased in the OP diets compared to the two control diets while Bacteroidetes increased, indicating a positive correlation with reduced body fat and weight. Drum‐dried pitted OP is a novel agricultural by‐product with its bioactive compounds having the potential to be incorporated in feeds and foods providing health benefits. Practical Application Drum‐dried pitted olive pomace can be produced from first or second olive oil extraction byproducts to be used as a shelf‐stable healthy food or feed supplement.

Health Benefits of High Protein and Dietary Fiber Dry-Fractioned Brewery Spent Grain Fines

“…31 The fat content in the liver and stools was measured as previously described. 30 Plasma lipoprotein cholesterol was determined by size-exclusion chromatography as previously described. Briefly, the lipoprotein fractions were separated on a Superose 6HR HPLC column (Pharmacia LKB Biotechnology, Piscataway, NJ) and combined in a postcolumn reactor with an enzymatic cholesterol analysis mix (Cholesterol SL, Sekisui Diagnostics).…”

“…Fresh BSG was hot air-dried following the procedures described in Inzunza-Soto et al (2022). 30 Partial Milling and Dry Fractionation. BSG was partially milled at 2 s bursts in a Knifetec 1095 sample mill (Foss Analytical, HillerØd, Denmark).…”

“…Measurements to determine water activity in triplicate at 25 °C in dried BSG were done in an Aqua Lab 4TE (Decagon Devices Inc., Pullman, WA). 30 Protein, ash content, fat analysis, and soluble and insoluble fiber content were analyzed as previously described. 30 Amino Acid Analysis.…”

“…30 Protein, ash content, fat analysis, and soluble and insoluble fiber content were analyzed as previously described. 30 Amino Acid Analysis. This analysis was performed using a Hitachi L-8800 A amino acid analyzer (Hitachi Medical Systems).…”

“…Blood was collected in EDTA tubes, and plasma was separated as previously described. 30 Analysis of Blood, Organs, and Feces of Mice. The nitrogen content of 150 mg of dried feces for fecal protein was analyzed using an FP-628 TrueSpec N analyzer (Leco Corporation, St. Joseph, MI).…”