Examination of the interrelationships between nutrition, environmental sustainability and food-processing: A concept study using model diets.

Recent work has focused on understanding the link between diet quality and environmental impact, however it is also important to consider the role food processing plays in this relationship. Using model meal plans, this paper examines the link between nutrient content, environmental impact, and processing. Four distinct meal plans were considered - 'Healthy', 'Unhealthy', 'Healthy (plant-based)', 'Healthy (plant-based, processed)'. For each a variety of environmental impact, processing and nutritional composition metrics were compared. Alternative healthy eating index (AHEI) score for the Unhealthy diet was significantly lower than the other three diets. The 'Healthy (plant-based)' diet had the highest AHEI score but was not significantly different to the 'Healthy (plant-based, processed)' and 'Healthy' diet scores. The greenhouse gas emissions for the two plant based diets were not significantly different to each other or to the 'Healthy' diet but were significantly lower than the 'Unhealthy' diet. The 'Healthy', 'Unhealthy', and 'Healthy (plant-based)' diets had similar processing specific energy consumption values however, the 'Healthy (plant-based, processed)' diets had significantly greater specific energy consumption. There was no clear link between diet quality and food processing when considered using processing specific energy value. When the number of processes in each diet was estimated, the unhealthier diet had considerably more processes associated with it. Examining the interaction of nutritional quality, environmental impact and processing of diets in this way highlights the complexity of the inter-relationships. Understanding these interactions is necessary to support the transition to healthy diets from sustainable sources.

Serum 25-hydroxyvitamin D response to vitamin D supplementation using different lipid delivery systems in middle-aged and older adults: a randomised controlled trial.

Food fortification improves vitamin D intakes but is not yet mandated in many countries. Combining vitamin D with different dietary lipids altered vitamin D absorption in in vitro and postprandial studies. This randomised, placebo-controlled trial examined the effect of the lipid composition of a vitamin D-fortified dairy drink on change in 25-hydroxyvitamin D (25(OH)D) concentrations. Sixty-three healthy adults aged 50+ years were randomised to one of the following for 4 weeks: vitamin D-fortified olive oil dairy drink, vitamin D-fortified coconut oil dairy drink, vitamin D supplement or placebo control dairy drink. All vitamin D groups received 20 µg of vitamin D3 daily. Serum was collected at baseline and post-intervention to measure 25(OH)D concentrations and biomarkers of metabolic health. Repeated-measures general linear model ANCOVA (RM GLM ANCOVA) compared changes over time. There was a significant time × treatment interaction effect on 25(OH)D concentrations for those classified as vitamin D-insufficient (P < 0·001) and -sufficient at baseline (P = 0·004). 25(OH)D concentrations increased significantly for all insufficient participants receiving vitamin D3 in any form. However, for vitamin D-sufficient participants at baseline, 25(OH)D concentrations only increased significantly with the coconut oil dairy drink and supplement. There was no effect of vitamin D on biomarkers of metabolic health. Vitamin D fortification of lipid-containing foods may be used in lieu of supplementation when supplement adherence is low or for individuals with dysphagia. These results are important given the recent recommendation to increase vitamin D intakes to 15-20 µg for older adults in Ireland.

Enhancing the bioaccessibility of vitamin D using mixed micelles - An in vitro study.

Vitamin-D deficiency is a global issue and a food fortification strategy may reduce deficiency levels. Mixed micelles (MM) are crucial to vitamin-D absorption in vivo and may enhance vitamin-D food fortification. This study compared the ability of MM based delivery systems to oil-in-water emulsions to improve vitamin-D bioaccessibility in vitro. Vitamin-D loaded emulsions were formed with olive or coconut oil alone or with added l-α-phosphatidylcholine, as well as two MM based systems. Particle size throughout digestion, fatty acid release, and vitamin-D bioaccessibility were measured. After digestion, particles in the MM size range (∼6-10 nm) were observed for emulsions but not for MM based systems. The bioaccessibility of vitamin-D in olive and coconut emulsions was 75% and 78%, respectively, and âˆ¼ 90% with added l-α-phosphatidylcholine. Bioaccessibility for the MM alone was 93% and 90% when mixed with a protein/lactose base. Overall, MM show good potential as a delivery system for vitamin-D in vitro.

Postprandial 25-hydroxyvitamin D response varies according to the lipid composition of a vitamin D3 fortified dairy drink.

In-vitro evidence suggests that the lipid component of foods alters vitamin D absorption. This single-blinded, cross-over postprandial study examined the effect of changing the lipid component of a 20 µg vitamin D3 fortified dairy drink on postprandial 25(OH)D concentrations. Participants consumed one dairy drink per visit: a non-lipid, a pre-formed oleic acid micelle, an olive oil and a fish oil dairy drink. There was a significant time*drink*baseline status effect on 25(OH)D concentrations (p = 0.039). There were no time*drink, time or drink effects on 25(OH)D in vitamin D sufficient participants (>50nmol/L). However, there was an effect of time on changes in 25(OH)D concentrations after the olive oil dairy drink (p = 0.034) in vitamin D insufficient participants (<50nmol/L). There were no effects after the other diary drinks. Olive oil may improve vitamin D absorption from fortified foods. Further research is needed to examine the practical implications of changing the lipid component of fortified foods.

Improving vitamin D3 stability to environmental and processing stresses using mixed micelles.

Deficiency of vitamin-D is prevalent globally and can lead to negative health consequences. The fat-soluble nature of vitamin-D, coupled with its sensitivity to heat, light and oxygen limits its incorporation into foods. Mixed micelles (MM) have potential to enhance bioavailability of vitamin-D. This study explores the stability of MM to food processing regimes and their ability to protect vitamin-D. Subjecting MM to a range of shearing speeds (8,000-20,500 rpm) and to high pressure processing (600 MPa, 120sec) resulted in no change in MM size (4.1-4.5 nm). MM improved the retention of vitamin-D following exposure to UV-C light, near UV/visible light, and heat treatment. MM suspensions protected vitamin-D over a four week storage period at refrigeration or freezer conditions. Overall MM show potential to protect vitamin-D from degradation encountered in food processing and storage and may be beneficial as a mechanism to fortify foods with vitamin-D.

Vitamin D3 bioaccessibility: Influence of fatty acid chain length, salt concentration and l-α-phosphatidylcholine concentration on mixed micelle formation and delivery of vitamin D3.

Vitamin D (VD) is a fat-soluble vitamin with high deficiency levels evident globally. Bioaccessibility of VD is influenced by formation of mixed micelles (MM) during digestion. This study assessed the impact of fatty acid (FA) type, phospholipid concentration on MM formation and stability of MM to salts. MM formation occurred at NaCl and KCl concentrations ranging from 20 to 100 mM, when octanoic acid (C8) or stearic acid (C18) were used. MM hydrodynamic size increased with increasing l-α-phosphatidylcholine concentration (1.5-7.5 mM) for both C8 and C18, above which concentration MM did not form. FA chain length impacted MM with hydrodynamic size increasing from 3.8 nm for decanoic acid (C10) to 4.4 nm for C18. VD3 incorporation in MM was not influenced by the FA used (C10 or C18). Understanding stability and formation of MM and VD3 loading is an essential first step towards manipulating food structures for improving delivery of VD.