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Wild harvested edible insects are characterised by high protein and mineral contents with potential to contribute substantially to nutrition security. However, nutritional content is only beneficial when proteins are digestible and minerals bioaccessible. This study determined the effects of domestic processing on protein digestibility and mineral bioaccessibility of two wild harvested insect species: Eulepida mashona (beetle) and Henicus whellani (cricket). Samples of both insects were subjected to boiling, roasting, or combined boiling and roasting, imitating the way insects are traditionally prepared in Zimbabwe. Moreover, they were in vitro digested according to INFOGEST protocol. Boiling of both insects resulted in loss of protein as it leached into the boiling water. The raw insects had a higher protein in vitro digestibility than the boiled and roasted insects, and the maximal decrease in protein digestibility was around 25% for twice boiling of the beetles and for boiled and roasted crickets. For both insect species, boiling resulted in non-significant loss of iron and zinc. Iron was the least bioaccessible mineral in both insects, based on the concentrations of soluble mineral measured by ICP-AES. However, beetles had a much higher iron bioaccessibility (30.7%) as compared to crickets (8.11%). Interestingly, boiling resulted in about 50% decrease in iron and zinc bioaccessibility in both species while roasting did not. The reduced protein digestibility and mineral accessibility with processing can be explained by protein modification and interactions of minerals with other food components, such as chitin and phytochemicals. Because of the reduction in protein digestibility and mineral accessibility during boiling, roasting should be favoured over boiling and in any case short boiling time is recommended. Unlabelled Image • Eulepida mashona and Henicus whellani proteins are well digestible • Protein digestibility is negatively influenced by boiling and roasting • Iron and zinc content in insects remain stable after boiling • Boiling decreases iron and zinc bioaccessibility while roasting does not • Iron bioaccessibility is higher in beetles than in crickets [ABSTRACT FROM AUTHOR]

Dark green leafy vegetables (DGLVs) are considered as important sources of iron and vitamin A. However, iron concentration may not indicate bioaccessibility. The objectives of this study were to compare the nutrient content and iron bioaccessibility of five sweet potato cultivars, including three orange-fleshed types, with other commonly consumed DGLVs in Ghana: cocoyam, corchorus, baobab, kenaf and moringa, using the in vitro digestion/Caco-2 cell model. Moringa had the highest numbers of iron absorption enhancers on an "as-would-be-eaten" basis, β-carotene (14169 μg/100 g; p < 0.05) and ascorbic acid (46.30 mg/100 g; p < 0.001), and the best iron bioaccessibility (10.28 ng ferritin/mg protein). Baobab and an orange-fleshed sweet potato with purplish young leaves had a lower iron bioaccessibility (6.51 and 6.76 ng ferritin/mg protein, respectively) compared with that of moringa, although these three greens contained similar (p > 0.05) iron (averaging 4.18 mg/100 g) and β-carotene levels. The ascorbic acid concentration of 25.50 mg/100 g in the cooked baobab did not enhance the iron bioaccessibility. Baobab and the orange-fleshed sweet potato with purplish young leaves contained the highest levels of total polyphenols (1646.75 and 506.95 mg Gallic Acid Equivalents/100 g, respectively; p < 0.001). This suggests that iron bioaccessibility in greens cannot be inferred based on the mineral concentration. Based on the similarity of the iron bioaccessibility of the sweet potato leaves and cocoyam leaf (a widely-promoted "nutritious" DGLV in Ghana), the former greens have an added advantage of increasing the dietary intake of provitamin A. [ABSTRACT FROM AUTHOR]

Casein and soybean are superior quality proteins; however, these are known to inhibit mineral absorption. These investigations were aimed at enzymatic modification of these proteins and to study their effect on mineral bioaccessibility. Casein and soybean proteins were hydrolyzed with alcalase and trypsin individually under optimum conditions. The protein hydrolysates, prepared with different degrees of hydrolysis, were freeze dried, fortified with either iron or zinc and analyzed for bioaccessible mineralsin vitro. Proteolytic hydrolysis enhanced the bioaccessibility of iron and zinc in proportion to the degree of hydrolysis. Tryptic hydrolysis enhanced the bioaccessible iron from 1–4% in casein and from 1.3–3.3% in soybean. Alcalase hydrolysis showed a comparatively higher enhancement with both the proteins. Tryptic hydrolysis enhanced zinc bioaccessibity by 3-fold in casein and alcalase hydrolysis enhanced by 2- to 2.5-fold. In soybean, dephytinization showed a synergistic effect. In conclusion, enzymatic hydrolysis of proteins looks promising for enhancing bioaccessibility of minerals in protein matrices. [ABSTRACT FROM AUTHOR]

The in vitro bioaccessibility of iron in context to fortification of key foods to cereal based diets was studied to optimize the meals for enhanced iron bioaccessibility to meet the needs of vegetarian and non-vegetarian adult women. Four individual food items and thirty six composite meals were selected to represent a wide spectrum of meal ingredients. The four individual foods: chapati, rice, dal and saag were choosen on the basis of data reported on meal pattern of surveyed households of north India. The basic meals were then fortified with key food ingredients which may influence in vitro iron bioaccessibility. Eight selected key foods were salad, orange, lemonade, milk, curd, chicken, egg and tea. The results revealed that inclusion of 200 g of chicken, 135 g of salad and 120 g of orange to the basic meals of rice or chapati with either dal or saag enhanced iron bioaccessibility by 1.6 fold to 5.0 fold; 5.2 to 28.9 % and 4.7 to 10.7 %, respectively. The best enhancer of iron absorption for vegetarians was lemonade (250 ml) which resulted in 70.2 and 61.0 % increase of in vitro bioaccessibility of iron to the rice based meals with dal and saag, respectively. The inclusion of lemonade resulted in 1.3 fold increase in iron bioaccessibility in chapati based meals. The major inhibitors of iron bioaccessibility were egg and tea, the percent reduction caused by egg being 16.1 to 50.2 % while by tea, it was between 21.5 to 55.3 %. The study recommends that those vulnerable to iron deficiency should be encouraged to increase overall intake of iron from iron rich foods. The increase should be coupled with efforts to combine appropriate foods in the diet to enhance the bioaccessibility of iron and reduce inhibitory factors. [ABSTRACT FROM AUTHOR]

A refrigerated ready-to-eat food fortified with iron (Fe) and ascorbic acid (AA) was produced using pumpkin ( Cucurbita moschata Duchesne ex Poiret) and applying a dry infusion process. It was observed that the presence of both Fe and AA in the vegetable matrix (control system) produced the browning of the product. The edible coatings application based on k-carrageenan or tapioca starch was proposed in order to improve the product stability. The AA degradation in the tissue was significantly reduced in the pumpkin with a starch-based coating. The result of an “in vitro” gastric and intestinal digestion assay indicated that when Fe was in the coating, Fe solubility at pH 2 was lower than control and tended to improve at pH 8. It was interpreted as a better accessibility of Fe at intestinal lumen level, and moreover, it could avoid gastric side effects. The products obtained were safe from microbiological view point and presented a satisfactory color and texture. Industrial relevance The formulation of food fortified with iron (Fe) represents a challenge from nutritional as well as technological view point because the reactivity of this mineral with other food matrix nutrients. This work proposes the elaboration of a vegetal refrigerated food, ready to eat, fortified with Fe and ascorbic acid (AA). The pumpkin was selected as raw material due its high consume and availability, proper nutritional characteristics and low cost. The dry infusion technique applied is sustainable, economic and with a minimal use of drinking water. In addition, biopolymer-based edible coatings were applied as an emerging technology for the carrying of micronutrients. It was demonstrated that when an edible coating was performed, the color and AA retention were improved and the Fe accessibility at pH of lumen intestinal trended to be higher. This study shows that the production of fortified pumpkin is simple and transferable to the food industry, and constituting a contribution from the food technology to the innovation of processes and formulation of a functional food fortified with Fe. [ABSTRACT FROM AUTHOR]

Dark green leafy vegetables (DGLVs) are considered as important sources of iron and vitamin A. However, iron concentration may not indicate bioaccessibility. The objectives of this study were to compare the nutrient content and iron bioaccessibility of five sweet potato cultivars, including three orange-fleshed types, with other commonly consumed DGLVs in Ghana: cocoyam, corchorus, baobab, kenaf and moringa, using the in vitro digestion/Caco-2 cell model. Moringa had the highest numbers of iron absorption enhancers on an “as-would-be-eaten” basis, β-carotene (14169 μg/100 g; p < 0.05) and ascorbic acid (46.30 mg/100 g; p < 0.001), and the best iron bioaccessibility (10.28 ng ferritin/mg protein). Baobab and an orange-fleshed sweet potato with purplish young leaves had a lower iron bioaccessibility (6.51 and 6.76 ng ferritin/mg protein, respectively) compared with that of moringa, although these three greens contained similar (p > 0.05) iron (averaging 4.18 mg/100 g) and β-carotene levels. The ascorbic acid concentration of 25.50 mg/100 g in the cooked baobab did not enhance the iron bioaccessibility. Baobab and the orange-fleshed sweet potato with purplish young leaves contained the highest levels of total polyphenols (1646.75 and 506.95 mg Gallic Acid Equivalents/100 g, respectively; p < 0.001). This suggests that iron bioaccessibility in greens cannot be inferred based on the mineral concentration. Based on the similarity of the iron bioaccessibility of the sweet potato leaves and cocoyam leaf (a widely-promoted “nutritious” DGLV in Ghana), the former greens have an added advantage of increasing the dietary intake of provitamin A.

The effect of removing phytate (IP6), iron-binding polyphenols, and dietary fibers on iron bioaccessibility in wheat-red sorghum (WrS) and teff-white sorghum (TwS) flour blends used in Ethiopia to make injera , a fermented pancake, was evaluated through the application of exogenous enzymes. Phytase treatment led to >90% reduction in IP6 and to an IP6:Fe molar ratio <1, but iron bioaccessibility was not improved ( P > 0.05). Phytase + xylanase + cellulase (P + X + C) treatment increased iron bioaccessibility in TwS (non-detectable to 1.6%) and WrS (1.9–3.2%), whereas phytase + polyphenol oxidase (P + PPO) treatment only showed improvement in the TwS blend. P + X + C + PPO treatment of the WrS blend increased the soluble non-dialysable iron fraction (6.7%) more than P + PPO treatment (3.9%). Although responses to enzyme treatments and iron bioaccessibility were matrix dependent, a positive effect of dietary fiber hydrolysis with X + C was obtained, irrespective of the blend. Dietary fibers had a negative effect on iron bioaccessibility independent of phytates. [ABSTRACT FROM AUTHOR]

• Dephytinisation of the complementary food mix by phytase activation and and thermal treatments. • Fortification of the complementary food mix and addition of fruit powders improved mineral bioaccessibiliy. • Addition of organic acids to improve iron and zinc bioacessibility. • Product meet 45%,40% and 36% need for protein, iron and zinc requirement. The investigation was undertaken to maximise the bioaccessibility of iron and zinc of a complementary food mix by multiple approaches of dephytinisation and addition of organic acids. A wheat, pulse and oilseed protein flour mix was dephytinized by phytase activation and different thermal treatments. As the mineral content of the mix was low, the spray dried mix was fortified with different iron and zinc salts to identify the salt with the highest bioaccessibility in this matrix. Based on the percent bioaccessibility, the mix with sodium iron EDTA and zinc oxide was chosen for fortification. Bioaccessibility was enhanced by the addition of fruit powders and pure organic acids. Fruit powders showed a significant increase, but citric acid at a higher dose was beneficial in enhancing bioaccessible iron. The strategy of dephytinisation followed by fortification and the addition of fruit powders or organic acids is promising in alleviating iron and zinc deficiencies. [ABSTRACT FROM AUTHOR]

Abstract: Watermelon (Citrullus vulgaris) seeds are high in protein and fat, on enriching protein, it can find application as a protein source in various food formulations. Most of the processed foods are generally fortified with micronutrients. The effect of the matrix on the mineral bioavailability is highly important and hence investigated. Defatted flour and protein isolate were prepared from watermelon seed meal and chemical composition and functionality was analyzed by standard techniques. Multiple regression analysis was done to study the compositional influence on the mineral bioaccessibility. Invitro digestibility of the protein was good. The seeds were a moderate source of iron and zinc. The percent bioaccessibility of all the minerals were found to correlate (R = 0.97–0.99) with the concentration of phytate, tannin and oxalate contents. The seed components exhibited good functionality with good macro and micronutrient density and can find application in many food products. [Copyright &y& Elsevier]

Iron fortification is an important and difficult task since most of the bioavailable iron sources are reactive against food matrix. Microencapsulation technology can prevent iron interaction with food matrix. Co-microencapsulation of iron and ascorbic acid was carried out by spray-drying using a protein concentrate obtained from brewers' spent grain (BSG-PC) and locust bean gum as chelating wall materials. Microcapsules were formulated using a 22 factorial design. The effect of BSG-PC/wall material (8.6 and 17.2 g protein 100 g−1) and ascorbic acid/iron molar ratio (0.9:1 and 1.8:1) on iron encapsulation yield (FeE), ascorbic acid encapsulation (AAE), iron chelated by wall material (FeC), iron bioaccessibility (FeB), particle size, zeta potential, and surface hydrophobicity of the microcapsules were assessed. Higher level of BSG-PC increased FeB at low ascorbic acid/iron molar ratio due to the high iron-chelating activity of BSG proteins (IC50: 7.9 ± 1.2 mg mL−1). At low levels of BSG-PC, FeB was promoted by ascorbic acid in a dose response way. A multiple response maximization of FeE, AAE, FeB, and FeC was performed and validated. Optimal microcapsule formula resulted with 29% of FeB after simulated gastrointestinal digestion. The optimization procedure allowed obtaining a fortifier with the higher iron bioaccessibility and iron content. • Iron and ascorbic acid were co-microencapsulated by spray drying. • Brewers' spent grain polypeptides play an important role as chelating wall material. • Brewers' spent grain proteins and polypeptides reduce oxidation of ascorbic acid. • Iron chelated by wall material and iron bioaccessibility were maximized. • Optimization procedure allowed obtaining a fortifier with high Fe bioaccessibility. [ABSTRACT FROM AUTHOR]