Nutritional studies with food vehicles containing seaweed and seaweed bioactives : effects on plasma lipids and glucose

Abstract

Evidence would indicate that obesity, as a public health problem, is rising. It is associated with several non‐communicable diseases, lower psychosocial wellbeing, and elevated risk of death. Brown seaweeds and their extract alginates have shown lipase inhibition, attenuating dietary fat digestion, absorption, and could be a possible agent for reducing obesity. Work from our lab has shown significant inhibition of pancreatic lipase action in vitro by specific alginate. Importantly, alginate has the potential to be a natural alternative for Orlistat (a lipase inhibitor), an anti-obesity drug which has gastrointestinal (GI) side effects. Therefore, the focus of this thesis has been on the addition of brown marine non-digestible polysaccharides (alginate) into enriched fat food products such as cheese and pork sausage, maintaining food acceptability and gastrointestinal wellbeing. This aim was achieved through two human intervention studies to assess the acceptability and ease of habitual diet incorporation of novel cheese and pork sausage containing brown seaweed and alginate. Their effect on gastrointestinal wellbeing functions was also examined. In the first study, the participants consumed seaweed, alginate, and control cheese weekly and in the second the participants consumed alginate and control sausages weekly. The results showed no significant changes in macronutrients intake of calories, carbohydrate, fat, and protein and no significant change to the GI wellbeing such as fullness, bloatedness, flatulence, anxiousness, and fitness. However, fibre intake in the alginate sausage week was significantly increased. It was concluded that consuming alginate and seaweed cheese and sausage were acceptable and had no impact on GI wellbeing. An acute feeding of alginate and control pork sausage meal that investigated the fat and carbohydrate digestion showed that alginate attenuated serum triglycerides concentration in a small sample of healthy participants with no effect on plasma glucose. The static in vitro digestion of enriched alginate foods carried out by the synthetic model gut system, allowed for measurement of glycerol released and alginate quantification. This shows a significant reduction in fat digestion by the seaweed cheese.