New insights into the digestion and bioavailability of a high-melting-temperature solid triacylglycerol fraction in bovine milk fat.

Clarifying the health risks associated with the consumption of high-melting-temperature solid triacylglycerol (TAG) from milk fat has profound significance for the nutritional evaluation and development of new dairy products. Our previous work effectively separated butterfat into solid/liquid fractions (30S and 30L) at 30 °C and successfully reconstituted milk fat globules (MFGs) with these fractions. The current study examined the postprandial digestive and daily metabolic properties of a high-melting-temperature solid TAG fraction by performing animal experiments (rats) with 30S-reconstituted MFG emulsion gavage for 240 min and 30S-containing diet administration for 4 weeks. Compared to the consumption of whole butterfat, 30S consumption altered apolipoprotein levels and did not lead to dyslipidaemia in the rats. Conversely, 30S administration induced significant body weight loss by enhancing satiety signals (glucagon-like peptide 1, GLP-1; cholecystokinin, CCK; and peptide YY, PYY), increasing faecal losses, and upregulating the level of hepatic lipolysis-associated enzymes (hormone-sensitive lipase, HSL; adipose triglyceride lipase, ATGL; and protein kinase A, PKA). The 30S diet efficiently improved adipocyte hypertrophy and reduced fat accumulation by downregulating the level of acetyl-CoA carboxylase (ACC) in adipose tissue. This study is of relevance to nutrition science and the dairy industry.

Structural and functional characteristics of optimised dry-heat-moisture treated cassava flour and starch.

The flexibility of hydrothermal conditions gives rise to an array of effects on the properties of starch-containing systems. This study examined and optimised moisture, temperature and time conditions with regards to functional properties of cassava flour and starch. The derived optimal conditions for cassava flour were 25%, 90 °C and 45 min, respectively, while cassava starch were 27%, 120 °C and 21 min, respectively. Consequently, effect of the optimal conditions on structural, physicochemical, rheological and melting characteristics of cassava flour and starch were studied. Optimal heat-moisture treatments changed both morphology and size distribution of cassava flour and starch granules. Relative crystallinity of cassava flour increased (34 to 40%) and cassava starch decreased (32% to 23%) following optimal-heat-moisture treatment. Both cassava flour and starch upon optimal dry-heat-moisture treatment exhibited enhanced; swelling power (15.57 to 21.62 g/g and 17.24 to 19.64 g/g, respectively), peak viscosity (3555 to 5493 cP and 6377 to 8701 cP, respectively), elasticity (tan δ) (0.31 to 0.24 and 0.58 to 0.47, respectively) and melting onset temperature to conclusion temperature range (14.66 to 15.75 °C and 23.26 to 30.69 °C, respectively). This research presents hydrothermal conditions that can effectively be applied in industry to improve the bakery potentials of cassava flour and starch.

Impact of steam-heat-moisture treatment on structural and functional properties of cassava flour and starch.

In this study, moisture, steam-temperature and time conditions were optimised in relation to functional properties of cassava flour and starch. The optimal conditions for cassava flour were 15% moisture, 120 °C and 1 bar for 10 min and for cassava starch were 19% moisture, 120 °C and 1 bar for 20 min. Structural, physicochemical, viscoelastic and thermal characteristics of cassava flour and starch upon the optimal steam-heat-moisture treatments were examined Volume-based diameter (D(4.3)) of cassava flour granules reduced (107.87 to 42.94 µm) and cassava starch granules increased (17.67 to 50.88 µm) when subjected to optimal steam-heat-moisture treatments. The optimal steam-heat-moisture treatments had no effect on the crystal patterns of cassava flour and starch (A-type), nonetheless, relative crystallinity of cassava flour was increased (34 to 59%) and cassava starch was decreased (32 to 27%). Increments in swelling power (17.24 to 19.07 g/g) and peak viscosity (6377 and 7330 cP) and, reductions in solubility and loss factor (tanδ) were ensued by the optimal steam-heat-moisture treatment of cassava starch. Both optimal steam-heat-moisture treatments of cassava flour and starch had increased thermal stability but reduced breakdown viscosity, setback viscosity (528 to 230 cP and 1259 to 938 cP, respectively) and gelatinisation enthalpy.