Jan Frank

‘Loche’ squash ( Cucurbita moschata ) is an ancient cucurbit landrace from northern Peru, with deep cultural roots in the Moche cuisine tradition. To our knowledge, this is the first study to combine phytochemical profiling of raw and cooked pulp with standardized in vitro gastrointestinal digestion and intestinal cell-based assessment in this matrix. This study assessed the carotenoid, tocopherol, and (poly)phenol composition of raw and boiled pulp, evaluated bioaccessibility through standardized in vitro gastrointestinal digestion (INFOGEST), and investigated the effects of the bioaccessible fraction on intracellular glutathione levels in a Caco-2:HT29-MTX-E12 co-culture model. UHPLC-DAD-MS² tentatively identified 16 phytochemicals, including phenolic and hydroxycinnamic acids, coumarin, and glycosylated derivatives. Lutein and α-tocopherol were the predominant carotenoid and tocopherol in raw pulp, respectively. Boiling substantially reduced all quantified phytochemicals, with tocopherols showing the greatest losses (77–93%) and phenolic acids being nearly depleted (retention 7–11%). Bioaccessibility was compound-specific: zeaxanthin showed the highest micellarization efficiency (70.9%), tocopherols were moderately to highly bioaccessible, and phenolic acids were poorly recovered (≤ 3.6%). No significant effects on cell viability or intracellular glutathione levels were observed. These findings support the nutritional valorization of this culturally significant Andean crop.

Rice (Oryza sativa L.) is a globally consumed staple food, commonly in its white rice form. However, milling processes such as dehusking and polishing remove nutrient-dense outer layers, causing significant losses of key compounds like vitamin E, minerals, and other bioactives (i.e. γ-oryzanol and polyphenols). This study evaluated the impact of rice milling on nutrient retention in 11 rice samples from subspecies Indica, Aromatic, and Japonica grown in Costa Rica, and for selected samples examined the in vitro bioaccessibility and Caco-2 cellular absorption of major bioactive compounds in rice bran. Samples were processed into white rice and rice bran and analyzed for vitamin E (tocopherols and tocotrienols) and mineral content. White rice contained 66% less vitamin E and 75% fewer minerals than bran, and no clear association was observed between degree of milling and vitamin E loss, suggesting that variation in nutrient retention is more closely related to intrinsic sample characteristics than to milling degree. The in vitro digestion followed by Caco-2 cell assays was used to measure bioaccesibility and absorption of γ-tocotrienol, γ-oryzanol, and ferulic acid from bran. Ferulic acid demonstrated the highest digestive stability, solubility, bioaccesibility (186-1159%) and absorption (0-20%). Γ-Oryzanol showed moderate bioaccesibility (59-162%) and uptake (maximum 0.1-0.7%), likely due to its esterified form, while γ-tocotrienol, though bioaccesible (32-241%), had no detectable absorption. These results confirm rice bran as a valuable source of bioavailable antioxidants and underscore the need to optimize processing methods to retain its nutritional properties.

Quinoa seeds contain high amounts of minerals, carotenoids, and tocochromanols (vitamin E) and can be classified into bitter and nonbitter genotypes based on their saponin contents. Saponins may form complexes with minerals and cholesterol, but their impact on the bioaccessibility of minerals, carotenoids, and tocochromanols from quinoa is unknown. We therefore subjected the seeds of 12 quinoa genotypes (n = 6 bitter, n = 6 nonbitter) to in vitro digestion and quantified the concentrations of the nutrients in digesta. Bitter and nonbitter quinoa did not differ in digestive stability, solubility, bioaccessibility, and micellar efficiency of these compounds. Mineral bioaccessibility was low, whereas that of the lipid-soluble compounds was low to medium. The mean micelle sizes and negative surface charges of mixed micelles did not differ between bitter and nonbitter quinoa seeds. In conclusion, the saponins in quinoa do not appear to affect micellar characteristics or to impair the bioaccessibility of minerals, carotenoids, and tocochromanols.

Fiber‐rich rye foods reduced body weight in overweight or obese individuals compared to refined wheat, though the underlying mechanisms remain unclear. This study compared the effects of whole grain fermented and unfermented rye with refined wheat crispbread on body weight and lipid metabolism in rats. Exploratory outcomes included adiposity, appetite biomarkers, glucose homeostasis, colon inflammation, integrity, and permeability. Sprague Dawley rats ( n = 54) were acclimatized (2 weeks) and randomized to control ( n = 9) or high‐fat diets ( n = 45) for 16 weeks. Animals in the high‐fat group were randomized to continue the high‐fat ( n = 9) or receive a standard diet alone ( n = 9) or the standard diet with either refined wheat crispbread ( n = 9), fermented rye crispbread ( n = 9), or unfermented rye crispbread ( n = 9) for 8 weeks. A high‐fat diet did not affect final body weight, glucose homeostasis, and colon inflammation, but increased energy intake, adiposity, and leptin compared to control, and hepatic triacylglycerols compared to all other groups. Unfermented rye crispbread increased plasma HDL‐cholesterol and reduced hepatic triacylglycerols and cholesterol compared to refined wheat, despite the absence of effects on obesity and glycemic control. No differences were observed between fermented and unfermented rye. Unfermented whole‐grain rye crispbread may potentially exhibit favorable lipid‐modulating effects.