What is food-to-food fortification? A working definition and framework for evaluation of efficiency and implementation of best practices.

Food-to-food fortification (FtFF) is an emerging food-based strategy that can complement current strategies in the ongoing fight against micronutrient deficiencies, but it has not been defined or characterized. This review has proposed a working definition of FtFF. Comparison with other main food-based strategies clearly differentiates FtFF as an emerging strategy with the potential to address multiple micronutrient deficiencies simultaneously, with little dietary change required by consumers. A review of literature revealed that despite the limited number of studies (in vitro and in vivo), the diversity of food-based fortificants investigated and some contradictory data, there are promising fortificants, which have the potential to improve the amount of bioavailable iron, zinc, and provitamin A from starchy staple foods. These fortificants are typically fruits and vegetables, with high mineral as well as ascorbic acid and ß-carotene contents. However, as the observed improvements in micronutrient bioavailability and status are relatively small, measuring the positive outcomes is more likely to be impactful only if the FtFF products are consumed as regular staples. Considering best practices in implementation of FtFF, raw material authentication and ingredient documentation are critical, especially as the contents of target micronutrients and bioavailability modulators as well as the microbiological quality of the plant-based fortificants can vary substantially. Also, as there are only few developed supply chains for plant-based fortificants, procurement of consistent materials may be problematic. This, however, provides the opportunity for value chain development, which can contribute towards the economic growth of communities, or hybrid approaches that leverage traditional premixes to standardize product micronutrient content.

African Adansonia digitata fruit pulp (baobab) modifies provitamin A carotenoid bioaccessibility from composite pearl millet porridges.

Food-to-food fortification of staple cereal products using nutrient-dense plants shows promise to address multiple micronutrient deficiencies including vitamin A, iron and zinc in Sub-Saharan Africa. However, there is limited information on the potential interaction effects that such food-to-food fortified strategies may have on individual micronutrient bioavailability. The main objective of the current study was to investigate the impact of incorporating Adansonia digitata (baobab fruit pulp), a mineral-rich plant material, on the delivery of carotenoids from a composite cereal porridge. Formulations of native fruit/vegetable-cereal composites were screened for interactions which could influence both bioaccessibility and subsequent intestinal uptake of provitamin A carotenoids. Proportions of pearl millet flour and plant materials were dry blended to provide composite cereal porridges with total provitamin A carotenoid concentrations ranging from 3590.7 ± 23.4 to 3698.5 ± 26.5 µg/100 g (fw) and baobab concentrations ranging from 0 to 25% (dw).While there were no significant differences in provitamin A carotenoid bioaccessibility from porridge formulations containing 5 or 15% baobab, inclusion of 25% baobab resulted in a significant (p < 0.05) decrease in bioaccessibility (13.3%) as compared to the control (23.8%). Despite the reduced bioaccessibility, 6 h uptake efficiency of provitamin A carotenoids by Caco-2 human intestinal cells was not significantly altered by 25% baobab inclusion. These findings suggest that the inhibitory effects on carotenoid micellarization (bioaccessibility) observed with increased baobab addition may not ultimately limit the bioavailability of carotenoids.

Trait stacking simultaneously enhances provitamin A carotenoid and mineral bioaccessibility in biofortified Sorghum bicolor.

Vitamin A, iron, and zinc deficiencies are major nutritional inadequacies in sub-Saharan Africa and disproportionately affect women and children. Biotechnology strategies have been tested to individually improve provitamin A carotenoid or mineral content and/or bioaccessibility in staple crops including sorghum (Sorghum bicolor). However, concurrent carotenoid and mineral enhancement has not been thoroughly assessed and antagonism between these chemical classes has been reported. This work evaluated two genetically engineered constructs containing a suite of heterologous genes to increase carotenoid stability and pathway flux, as well as phytase to catabolize phytate and increase mineral bioaccessibility. Model porridges made from transgenic events were evaluated for carotenoid and mineral content as well as bioaccessibility. Transgenic events produced markedly higher amounts of carotenoids (26.4 µg g-1 DW) compared to null segregants (4.2 µg g-1 DW) and wild-type control (Tx430; 3.7 µg g-1 DW). Phytase activation by pre-steeping flour resulted in significant phytate reduction (9.4 to 4.2 mg g-1 DW), altered the profile of inositol phosphate catabolites, and reduced molar ratios of phytate to iron (16.0 to 4.1), and zinc (19.0 to 4.9) in engineered material, suggesting improved mineral bioaccessibility. Improved phytate : mineral ratios did not significantly affect micellarization and bioaccessible provitamin A carotenoids were over 23 times greater in transgenic events compared to corresponding null segregants and wild-type controls. A 200 g serving of porridge made with these transgenic events provide an estimated 53.7% of a 4-8-year-old child's vitamin A estimated average requirement. These data suggest that combinatorial approaches to enhance micronutrient content and bioaccessibility are feasible and warrant further assessment in human studies.

Mixed Berry Juice and Cellulose Fiber Have Differential Effects on Peripheral Blood Mononuclear Cell Respiration in Overweight Adults.

Berries and other anthocyanin-rich foods have demonstrated anti-obesity effects in rodents and humans. However, the bioactive components of these foods and their mechanisms of action are unclear. We conducted an intervention study with overweight and obese adults to isolate the effects of different berry components on bioenergetics. Subjects consumed whole mixed berries (high anthocyanin, high fiber), pressed berry juice (high anthocyanin, low fiber), berry-flavored gelatin (low anthocyanin, low fiber), or fiber-enriched gelatin (low anthocyanin, high fiber) for one week prior to a meal challenge with the same treatment food as the pre-feed period. Peripheral blood mononuclear cells were collected 2 h after the meal challenge, and cellular respiration was assessed via high-resolution respirometry. The high-anthocyanin, low-fiber treatment (berry juice) and the low-anthocyanin, high-fiber treatment (fiber-enriched gelatin) had opposite effects on cellular respiration. In the fasted state, berry juice resulted in the highest oxygen-consumption rate (OCR), while fiber-enriched gelatin resulted in the highest OCR in the fed state. Differences were observed in multiple respiration states (basal, state 3, state 4, uncoupled), with the greatest differences being between the pressed berry juice and the fiber-enriched gelatin. Different components of berries, specifically anthocyanins/flavonoids and fiber, appear to have differential effects on cellular respiration.

Co-extruded wheat/okra composite blends result in soft, cohesive and resilient crumbs rich in health-promoting compounds.

This work investigates the partial solubilization of cell wall polysaccharides in okra flours and the changes in the profile of free and bound phenolics through twin-screw extrusion. The comparison between extruded wheat flour-native okra flour (EWF-OF) and extruded wheat flour-extruded okra flour (EWF-EOF) composite blends revealed that extrusion led to an increase of soluble dietary fiber from 7.76 to 10.02 g/100 g. Extrusion of okra also resulted in a significant increase of free and bound phenolic acids, the latter consisting mostly of ferulic acid, as well as the thermal degradation of free epigallocatechin, and the binding of a small portion of quercetin-3-O-glucoside likely to a carbohydrate fraction. Bread crumbs from EWF-EOF (at 15% replacement level) exhibited a significantly lower hardness and higher elasticity, cohesiveness and resilience (from 28.28 N, 0.94, 0.49 and 0.17 to 7.54 N, 0.99, 0.70 and 0.35, respectively), which closely resembled the textural attributes of wheat bread.

Effects of Concord grape juice flavor intensity and phenolic compound content on glycemia, appetite and cognitive function in adults with excess body weight: a randomized double-blind crossover trial.

Background & aims: Concord grape (Vitis lambrusca) juice (CGJ) contains a unique combination of polyphenolic compounds with diverse effects on human health. It also has an intense sensory profile that may modify food choice. Daily consumption of CGJ over 8 weeks reduced fasting blood glucose. However, the impact on 24h-postprandial glucose response from CGJ is still not clear. The purpose of this study was to assess the effect of CGJ flavor intensity and phenolic content on 24 h postprandial glucose concentrations, appetitive sensations, and cognitive function in adults with excess body weight when consumed alone or with a meal. Methods: In a randomized, double-blind, crossover design study, participants consumed three types of beverages: 100% CGJ, a polyphenol-free grape flavored drink with the same flavor essence (LP) or a polyphenol-free grape flavored drink with reduced flavor essence (LPF) either without (trial I) or with (trial II) a meal. 24 h glucose was measured through continuous glucose monitoring. Phenolic metabolite excretion was assessed in 24 h urine samples. Appetite (hunger, thirst, fullness, desire to eat, and prospective consumption) and cognitive function (alertness, energetic, strength, calmness, and relaxation) were assessed hourly through visual analog scales. Results: Thirty-four adults completed trial I and 34 adults completed trial II. When consumed with a meal, beverages with customary flavor essence (CGJ and LP) reduced hunger, desire to eat, and prospective consumption and consumption of the polyphenol-free reduced flavor essence beverage was associated with higher 24 h glucose tAUC. No consistent effects were observed for cognitive outcomes. When consumed alone, CGJ was related to lower glycemic responses by those excreting a higher concentration of the phenolic metabolite iso/ferulic-3'-O-glucuronide, but in beverages without CG phenolics and reduced flavor essence, glycemia was higher among those excreting higher concentrations of caffeic acid-O-sulfate. Conclusions: Both natural phenolics and flavor essence of CGJ may help to moderate appetite and glycemia. Clinical Trials registered at http://www.clinicaltrials.gov: NCT03409484 (trial I) and NCT03409497 (trial II).

Increasing Doses of Blueberry Polyphenols Alters Colonic Metabolism and Calcium Absorption in Ovariectomized Rats.

SCOPE: Blueberries are rich sources of bioactive polyphenols that may provide health benefits when consumed regularly, leading to their increased marketing as dietary supplements. However, the metabolic changes associated with consuming concentrated doses of purified polyphenols, as may be present in dietary supplements, are unknown, especially when considering the colonic metabolites formed. This study aimed to evaluate the pharmacokinetics of high doses of purified blueberry polyphenols. METHODS AND RESULTS: 5-month old, ovariectomized Sprague-Dawley rats are acutely dosed with purified blueberry polyphenols (0, 75, 350, and 1000 mg total polyphenols per kg body weight (bw)) and 45 Ca to measure calcium absorption. Blood and urine are collected for 48 h after dosing and phenolic metabolites measured via ultra high-pressure liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The most prominent metabolites are colonically generated cinnamic and hippuric acids. Smaller amounts of other phenolic acids, flavonols, and anthocyanins are also detected. Most metabolites follow a dose-response relationship, though several show saturated absorption. Maximal metabolite concentrations are reached within 12 h for a majority of compounds measured, while some (e.g., hippuric acid) peaked up to 24 h post-dosing. Calcium absorption is significantly increased in the highest dose group (p = 0.03). CONCLUSION: These results indicate that increased doses of blueberry polyphenols induce changes in intestinal phenolic metabolism and increase calcium absorption.

Development of a genetic framework to improve the efficiency of bioactive delivery from blueberry.

In the present study, we applied a novel high-throughput in vitro gastrointestinal digestion model to phenotype bioaccessibility of phenolics in a diverse germplasm collection representing cultivated highbush blueberries. Results revealed significant (P < 0.05) differences between accessions, years, and accession by year interaction for relative and absolute bioaccessibility of flavonoids and phenolic acids. Broad sense heritability estimates revealed low to moderate inheritances of relative and absolute bioaccessibility, suggesting that besides environmental variables, genetics factors could control bioaccessibility of phenolics. Acylated anthocyanins had significantly higher relative bioaccessibility than non-acylated anthocyanins. Correlation analysis indicated that relative bioaccessibility did not show significant association with fruit quality or raw concentration of metabolites. The study also identified accessions that have high relative and absolute bioaccessibility values. Overall, combining the bioaccessibility of phenolics with genetic and genomic approaches will enable the identification of genotypes and genetic factors influencing these traits in blueberry.

An Anthocyanin-Rich Mixed-Berry Intervention May Improve Insulin Sensitivity in a Randomized Trial of Overweight and Obese Adults.

Evidence supports the beneficial effects of berries on glucoregulation, possibly related to flavonoid content, fiber content, or both. The purpose of this study was to assess the potential of mixed berries to improve insulin sensitivity and to identify the potential role of flavonoids and fiber. In a randomized cross-over trial with four treatment periods, overweight/obese men and women were fed a controlled 45% fat diet for one week prior to a meal-based glucose tolerance test. The same base diet was provided during each feeding period with the addition of one of four treatments: whole mixed berries, sugar matched mixed berry juice, sugar matched gelatin, and sugar/fiber matched gelatin. Subjects then completed a meal-based oral glucose tolerance test. Serum glucose, insulin and non-esterified fatty acids were not different between individual treatments. However, in a secondary analysis, the combined berry preparations resulted in a lower serum insulin area under the curve (difference of 0.15 ± 0.066 ln pmol min/mL, mean ± SE, p = 0.0228), compared to the combined gelatin treatments, while the difference for serum glucose did not quite meet statistical significance (difference of 0.17 ± 0.093 ln mg·min/dL, mean ± SE, p = 0.0738). These results suggest the potential for mixed berry preparations to improve post-prandial insulin response.