Optimising the ratio of long- to short-chain triglycerides of the lipid phase to enhance physical stability and bioaccessibility of lycopene-loaded beverage emulsions

Oil-in-water beverage emulsions (pH3.2) with different long- to short-chain triglyceride (LCT to SCT) ratios were used to encapsulate lycopene. Beverages containing 3% w/w oil from carrier lipids were prepared as follows (w/w): 100:0, 75:25, 50:50, 25:75, and 0:100 (corn oil:tributyrin). The beverages prepared using a low LCT to SCT ratio (0:100) were physically unstable mainly due to Ostwald ripening phenomena, as indicated by confocal laser microscopy. The oil droplet size was significantly reduced for emulsions formulated with corn oil (2.6 μm) compared with tributyrin (5.4 μm). Lycopene was not bioaccessible in beverages formulated with tributyrin only and bioaccessibility increased significantly with increasing the LCT to SCT ratio. Data indicated that bioaccessibility for lycopene is 2.7% for emulsions with high LCT ratios (>75). Results indicate that the carrier lipid phase of emulsion-based systems is critical for the formulation of functional drinks for the delivery of lipophilic bioactive compounds.     

Physiochemical and nutritional characteristics,bioaccessibility and sensory acceptance of baked crackers containing broccoli co-products

The effects of the inclusion of broccoli co-products into crackers on the bioaccessibility as well as their overall physical and nutritional quality were evaluated. Crackers were formulated using a 12.5 or 15.0% flour substitution level. Broccoli-containing crackers presented higher specific volume and spread ratio and lower weight and specific volume than control crackers (P < 0.05). Crackers containing broccoli co-products showed an increased green hue and a higher colour intensity (P < 0.05). Incorporation of broccoli co-products into crackers significantly increased the total phenolic content and antioxidant capacity (P < 0.05). A simulated gastrointestinal digestion suggested that the amount of phenolic and antioxidant compounds released during digestion might be higher than what could be expected from common water-organic extracts. The incorporation of broccoli co-products into baked crackers would not only reduce the amount of food discarded as waste but also promote health and open novel commercial opportunities to food processors.     

Characterisation of O/W emulsions encapsulating ergocalciferol using onion skin waste saponins: insights on formulation and release properties

The study was conducted to produce ergocalciferol (Vit-D₂) loaded oil-in-water (O/W) emulsions utilising the onion skin waste saponins (OSW) as a natural emulsifier and almond oil as carrier oil. The impact of different formulations upon the digestibility of lipids, LCT (long-chain triglycerides) or MCT (medium-chain triglycerides), and bioaccessibility of Vit-D₂ was analysed. The mean particle size diameter of almond oil-based O/W emulsions was decreased with increasing homogenisation pressure and emulsifier concentration. During 120 mins of digestion in small intestinal fluids (SIF), almond oil in high-lipid emulsions (5% w/w) was not fully digested, resulting in a lower bioaccessibility of ergocalciferol than low-lipid samples. Almond oil emulsions with larger particle size have a slower rate of lipid digestion than the smaller size particles, but the release rate of free fatty acids was constant throughout the digestion process. Moreover, almond oil emulsions showed similar Vit-D₂ bioaccessibility to the oil-based emulsions but were much higher than MCTs.     

In vitro calcium bioaccessibility in raw and cooked cladodes of prickly pear cactus (Opuntia ficus-indica L. Miller)

The aim of this work was to determine the calcium bioaccessibility in Opuntia ficus indica L. Miller cultivars (Milpa Alta and Atlixco) and to evaluate the effect of cooking by using an in vitro digestion and dialysis method. The studied cladodes had a high content of calcium; however, only 16 and 9% of total calcium was dialyzable in Milpa Alta and Atlixco cultivars, respectively. The calcium dialyzability of Milpa Alta could be classified as medium level (10-19%) and Atlixco at the top of the rank assigned to low food dialyzability (<10%). Our results presented a significant negative correlation, between total oxalate and ionic dialyzable calcium (r = - 0.716, P ≤ 0.05). Milpa Alta could be a better source of calcium due to the higher bioaccessibility of ionic dialyzable calcium and lower total oxalate/calcium ratio. The cooking process did not affect significantly intestinal calcium bioaccessibility in any of the cultivars studied.     

Enhanced Bioaccessibility of Curcuminoids in Buttermilk Yogurt in Comparison to Curcuminoids in Aqueous Dispersions

Curcuminoids have low bioavailability due to low aqueous solubility. We compared the bioaccessibility of curcuminoids delivered in buttermilk yogurt to that of curcuminoid powder in an aqueous dispersion. Buttermilk containing added curcuminoids (300 mg/100 g, 0.3% w/w) was used for yogurt manufacture. We measured percentage of curcuminoids remaining in yogurts after manufacture and after exposure to simulated gastrointestinal fluids, and the in vitro bioaccessibility of the curcuminoids. Curcuminoids were stable during yogurt manufacture. At the end of in vitro digestion, approximately 11% of the curcuminoids delivered in yogurt was degraded compared to <1% for curcuminoids in an aqueous dispersion. However, curcuminoids delivered in yogurt was 15‐fold more bioaccessible than curcuminoids in aqueous dispersion. The small change in yogurt properties (decrease in total lactic acid bacteria counts of <1 log and increased viscosity) on addition of curcuminoids has to be balanced against the benefits of increased bioaccessibility of curcuminoids when delivered in yogurts.     

Stability of Trans‐Resveratrol Encapsulated in a Protein Matrix Produced Using Spray Drying to UV Light Stress and Simulated Gastro‐Intestinal Digestion

Trans‐resveratrol has demonstrated the potential to provide both therapeutic and preventive activities against chronic diseases such as heart disease and cancer. The incorporation of trans‐resveratrol into food products would allow for broader access of this bioactive compound to a larger population. However, this strategy is limited by instability of trans‐resveratrol under environmental conditions and within the digestive system leading to isomerization of trans‐resveratrol (bioactive form) to cis‐resveratrol (bio‐inactive form). Studies in the stabilization of trans‐resveratrol into protein microparticles are presented. Trans‐resveratrol was encapsulated using whey protein concentrate (WPC) or sodium caseinate (SC), with or without anhydrous milk fat (AMF). Binding of resveratrol and aromatic residues in protein was estimated utilizing the Stern–Volmer equation and the number of tryptophan residues. The stability of encapsulated resveratrol was evaluated after exposure to ultraviolet A (UVA) light and 3‐stage in vitro digestion. After UVA light exposure, SC‐based microcapsules maintained a higher trans:cis resveratrol ratio (0.63, P < 0.05) than WPC‐based microcapsules (0.43) and unencapsulated resveratrol (0.49). In addition, encapsulation of resveratrol in both protein microparticles led to an increased digestive stability and bioaccessibility in comparison to unencapsulated resveratrol (47% and 23%, respectively, P < 0.05). SC‐based microcapsules provided a higher digestive stability and bioaccessibility (86% and 81%; P < 0.05) compared to WPC‐based microcapsules (71% and 68%). The addition of AMF to the microcapsules did not significantly change the in vitro digestion values. In conclusion, SC‐based microencapsulation increased the stability of trans‐resveratrol to UVA light exposure and simulated digestion conditions. This encapsulation‐system‐approach can be extended to other labile, bioactive polyphenols.