Development of an extruded micronutrient delivery vehicle for the fortification of nixtamalised maize with chelated iron at the point of wet milling

The use of high‐temperature extrusion for the development of a micronutrient delivery vehicle (MDV), made of rice and maize (1:1 w/w), as part of a fortification technology for traditional nixtamalised maize (NM) masa at the point of use was evaluated. A Welly puffing extruder and a peristaltic pump were used to establish a uniform extrusion process for MDVs containing 302 ± 13 mg kg^?1 of NaFeEDTA or 656 ± 8 mg kg^?1 of ferrous bisglycinate. After manual premixing (30 s) of MDVs with NM (1:20 or 1:40 MDV:NM) and grinding with a pilot scale burr mill (5 min), iron distribution in masa was variable, ranging 3–21% RSD within sections of individual 2‐kg batches. Kneading (5 min) shortly after grinding resulted in uniformed iron distribution (<4% RSD). Despite the iron source and fortification level, fortified NM masa was harder and darker than control after 8‐h storage at room temperature; however, these changes require further sensory evaluation.     

γ-Oryzanol and tocopherol contents in residues of rice bran oil refining

Rice bran oil (RBO) contains significant amounts of the natural antioxidants γ-oryzanol and tocopherols, which are lost to a large degree during oil refining. This results in a number of industrial residues with high contents of these phytochemicals. With the aim of supporting the development of profitable industrial procedures for γ-oryzanol and tocopherol recovery, the contents of these phytochemicals in all the residues produced during RBO refining were evaluated. The samples included residues from the degumming, soap precipitation, bleaching earth filtering, dewaxing and deodorisation distillation steps. The highest phytochemical concentrations were found in the precipitated soap for γ-oryzanol (14.2 mg g⁻¹, representing 95.3% of total γ-oryzanol in crude RBO), and in the deodorisation distillate for tocopherols (576 mg 100 g⁻¹, representing 6.7% of total tocopherols in crude RBO). Therefore, among the residues of RBO processing, the deodorisation distillate was the best source of tocopherols. As the soap is further processed for the recovery of fatty acids, samples taken from every step of this secondary process, including hydrosoluble fraction, hydrolysed soap, distillation residue and purified fatty acid fraction, were also analyzed. The distillation residue left after fatty acid recovery from soap was found to be the best source of γ-oryzanol (43.1 mg g⁻¹, representing 11.5% of total γ-oryzanol in crude RBO).     

Effects of parboiling,storage and cooking on the levels of tocopherols,tocotrienols and γ-oryzanol in brown rice (Oryza sativa L.)

Vitamin E and γ-oryzanol display a wide range of biological activities including hypocholesterolemic, anti-inflammatory and antioxidant activities. Although white rice is far more popular worldwide, consumption of brown rice is increasing, partially on account of the presence of bioactive compounds; however, the effects of parboiling, storage and cooking on them are not well-characterized. The effects of parboiling and a 6-month storage period on the contents of vitamin E and γ-oryzanol in three brown rice cultivars grown in three different locations in Brazil were investigated. Also, their levels in branded non-parboiled and parboiled brown rice were monitored before and after cooking. Vitamin E homologues and γ-oryzanol were separated by RP-HPLC equipped with PDA and fluorescence detectors. The average levels of total tocols and γ-oryzanol in the raw brown rice cultivars studied were 25 and 188 mg/kg, respectively. Of the vitamin E homologues, γ-tocotrienol contributed with 74% of total tocols, followed by α-tocopherol, α-tocotrienol and γ-tocopherol in minor quantities. The combined processes, parboiling, storage and cooking, led to an approximate 90% reduction in tocols and only γ-tocotrienol was detectable after any of the processes. Parboiling followed by storage resulted in an approximate 40% loss of γ-oryzanol. Cooking had almost no further effect over γ-oryzanol levels in parboiled rice previously stored for 6 months.     

Evaluation of various Bacillus coagulans isolates for the production of high purity L-lactic acid using defatted rice bran hydrolysates

Defatted rice bran (DRB) constitutes an abundant by-product stream, generated during rice milling and subsequent bran oil extraction. Enzymatic hydrolysis of starch and protein content in DRB was optimised in terms of solid loading. Among the four solid loadings evaluated (10%, 15%, 20% and 25%), the hydrolysate derived from 20% solids resulted in the highest concentration of glucose (82.3 g L⁻¹) and free amino nitrogen (234.8 mg L⁻¹). The fermentability of the hydrolysate was evaluated via screening of sixteen isolates. All the strains were able to grow and produce high purity L-lactic acid, utilising the DRB as sole carbon and nutrient source. Among the studied strains, the Bacillus coagulans A107 isolate presented the most promising results in terms of final lactic acid concentration (75.9 g L⁻¹), yield (0.90 g g⁻¹) and productivity (2.7 g L⁻¹ h⁻¹). The results of this study indicate that DRB could be employed as an inexpensive, alternative substrate for L-lactic acid production.     

Variation of mineral contents with nutritional interest in a collection of Solanum tuberosum group Phureja tubers

Colombia has a biodiversity centre of diploid potatoes located at south of the country. This study evaluated the amounts of potassium (K), calcium (Ca), iron (Fe) and zinc (Zn) in a biodiversity panel of potato tubers, constituting native cultivars, accessions of the Working Collection of Potato Breeding Program at the Universidad Nacional de Colombia (CCC) and commercial cultivars. The highest quantity of minerals found were as follows: 34 333 ± 4509 mg K kg⁻¹ potato dry weight (DW; CCC112), 1965 ± 898 mg Ca kg⁻¹ potato DW (CCC23), 87.5 ± 8.8 mg Fe kg⁻¹ potato DW (CCC116) and 60.7 ± 5.1 mg Zn kg⁻¹ potato DW (CCC31). As compared to those in commercial cultivars, the currently evaluated tubers had an increase of 1.4, 12.5, 3.5 and 3.6-fold in K, Ca, Fe and Zn. These genotypes can be used in the future breeding programmes to enhance specific mineral contents in tubers.     

Quantification of major camel milk proteins by capillary electrophoresis

Proteins from dromedary camel milk (CM) produced in Europe were separated and quantified by capillary electrophoresis (CE). CE analysis showed that camel milk lacks β-lactoglobulin and consists of high concentration of α-lactalbumin (2.01 ± 0.02 mg mL⁻¹), lactoferrin (1.74 ± 0.06 mg mL⁻¹) and serum albumin (0.46 ± 0.01 mg mL⁻¹). Among caseins, the concentration of β-casein (12.78 ± 0.92 mg mL⁻¹) was found the highest followed by α-casein (2.89 ± 0.29 mg mL⁻¹) while κ-casein represented only minor amount (1.67 ± 0.01 mg mL⁻¹). These results were in agreement with sodium dodecyl sulphate-polyacrylamide gel electrophoresis patterns. Overall, CE offers a quick and reliable method for the determination of major CM proteins, which may be responsible for the many nutritional and health properties of CM.     

CFD simulation of ozone gas flow for controlling Sitophilus zeamais in rice grains

Ozone gas (O₃) is a prominent alternative for the integrated pest management of stored products. The present study fitted a computational fluid dynamics (CFD) model to elucidate the ozone gas flow dynamics in an aeration system, at a lethal concentration for Sitophilus zeamais Mots in rice grains. First, an experiment was carried out to understand the flow of ozone gas (2.2 mg L⁻¹; 2 L min⁻¹) in a cylindrical PVC column filled with 4 kg of rice grains. The ozone gas concentration was monitored every 12 h, at a point immediately above the grains. The gas flow was modeled using the CFD technique. The parameters used to feed the model and adjust it to the experimental data were the mass transfer coefficient and ozone-rice grain reaction constant. Then, a simulation of ozone gas injection in a silo with a static capacity of 69.6 tons of rice was performed. In the ozone gas injection experiment, 100% of insect mortality was observed on the sixth day, when the O₃ concentration reached 0.1 mg L⁻¹. In this case, the mass transfer coefficient was 0.55 m s⁻¹, and the reaction constant was 0.78 s⁻¹. At the concentration of 0.8 mg L⁻¹, it is possible to treat 69.6 tons of rice grains within 9 days.     

Iron content and availability studies in some Sri Lankan rice varieties

Thirty‐eight rice varieties, grown in Low Country Wet Zone, during Yala (2006) and Maha (2006/2007) seasons were screened for stable high iron rice varieties and were statistically analysed. Iron contents ranged 1.89–3.73 mg 100 g^?1 and varied significantly (P < 0.05) with variety and season. Selected fifteen high iron rice varieties, at degree of polishing 8–10% were analysed for iron, zinc and phytate. High iron contents in endosperm were observed in Suduru Samba (0.47 mg 100 g^?1), Basmati 370 (0.37 mg 100 g^?1), Kalu Heenati (0.42 mg 100 g^?1), Rathu Heenati (0.44 mg 100 g^?1) and Sudu Heenati (0.37 mg 100 g^?1). Phytate contents of polished rice varieties ranged from 200–300 mg 100 g^?1. Large reduction in iron content (84.5–93.6%) was observed in polished rice while the reduction in phytate content (18.9–40.8%) was low. Percentage dialyzability of iron in selected endosperm high iron rice varieties ranged from 1.73 to 8.71. Dialysability of iron in cooked polished rice did not show a relation to the phytate content in raw rice.     

Comparative study of the phenolics,antioxidant and metagenomic composition of novel soy whey-based beverages produced using three different water kefir microbiota

Water kefir microbiota was used to develop novel soy whey-based beverages that have antioxidant activity. In the present study, comparative phenolics, antioxidant and metagenomic composition of the soy whey beverages fermented using three different water kefir microbiota, named WKFS-A, WKFS-B and WKFS-C were investigated. WKFS-B beverage had the highest concentrations of isoflavone aglycones (208.73 ± 2.78 mg L⁻¹) and phenolic acids (132.33 ± 3.41 mg L⁻¹) compared with WKFS-A (193.88 ± 1.15 mg L⁻¹) and (91.73 ± 2.34 mg L⁻¹) and WKFS-C (160.63 ± 1.76 mg L⁻¹) and (97.13 ± 2.63 mg L⁻¹), respectively. The WKFS-B also showed higher DPPH and ABTS radical scavenging activity and ferric reducing antioxidant power compared with WKFS-A and WKFS-C beverages. Microbial species diversity index analysis showed that a higher concentration of isoflavone aglycones, phenolic acids and increased antioxidant activity in the WKFS-B beverage correlates with the higher relative abundance of Lactobacillus genus. This study thus revealed that Lactobacillus dominated water kefir microbiota produces soy whey beverages with high phenolic acids, isoflavone aglycones and antioxidant activity.     

Nanofiltration process for the nutritional enrichment and refining of rice bran oil

Crude rice bran is a natural source of γ-oryzanol, a nutritionally valuable phytochemical with antioxidant properties. In the present paper the refining and γ-oryzanol enrichment of rice bran oil was investigated through solvent extraction optimization and nanofiltration processing. Several solvent resistant nanofiltration membranes were screened and successfully applied in a two step membrane cascade with fluxes between 39 and 53 L m⁻² h⁻¹. A first membrane stage operation provided the separation between glycerides and γ-oryzanol, promoting the oil enrichment in this phytochemical. In the second membrane stage the oil could be refined to acceptable consumption levels (FFA < 0.20 wt.%) and its γ-oryzanol content was further enhanced. Overall, the integrated process provided a RBO γ-oryzanol enrichment from 0.95 to 4.1 wt.% in oil, which corresponded to more than a two fold increase in the oil’s antioxidant capacity. These results demonstrate the potential of organic solvent nanofiltration as a technology to enrich and refine oil based products.     

Preparation of iron‐fortified rice using edible coating materials

Iron‐fortified rice premix (IFRP) was prepared using soaking and spraying method followed by coating with hydroxypropyl methyl cellulose (HPMC), methyl cellulose (MC), combination of HPMC and MC, zein, palmitic acid (PA) and stearic acid (SA). Steaming caused a reduction in iron content in iron‐fortified rice premix than without steaming treatment. Iron content ranged from 1.33 to 7.11 and 1.61 to 4.49 mg g^?1, respectively, in IFRP prepared using soaking and spraying method. Retention of iron in IFRP samples coated with 9% PA, 7% and 9% SA, and combination of HPMC and MC at 2% level, respectively, after washing twice with distilled water was similar (P > 0.05). Retention of iron in these coated IFRP ranged from 87.34% to 89.39% (P > 0.05) as compared to 39.12% in uncoated IFRP. Sensory acceptability indicated the scope for the production of IFRP by spraying of iron solution with iron content 20.1 mg mL^?1, 180‐min tempering time and coating with 2% HPMC and MC followed by drying.     

Pyropia columbina phycocolloids as microencapsulating material improve bioaccessibility of brewers’ spent grain peptides with ACE-I inhibitory activity

The effects of wall hydrocolloids on delivery and bioaccessibility of encapsulated brewers’ spent grain ACE-I inhibitory peptides after simulated gastrointestinal digestion were assessed. Microencapsulation of peptides was carried out by spray drying using locust bean gum, P. columbina phycocolloids, or its mixtures as wall materials. Microcapsules presented round external surfaces with some concavities, negative surface charge and encapsulation efficiencies higher than 90%. The incorporation of phycocolloids to formulations increased the encapsulation efficiency, negative surface charge and resistance against digestive enzymes of microcapsules. Encapsulated peptides with P. columbina phycocolloids showed lower IC₅₀ value of ACE-I inhibition than un-encapsulated peptides (2.4 ± 0.2 vs. 7.2 ± 0.3 mg mL⁻¹ protein), but higher than that obtained for hydrolysate (1.5 ± 0.2 mg mL⁻¹ protein), indicating a 75% protection of bioactivity. Electrostatic and hydrophobic interactions between P. columbina phycocolloids and brewers’ spent grain peptides could be implicated in the protection of peptides during gastrointestinal digestion.     

Effects of polyphenol oxidation on in vitro iron availability in faba bean (Vicia faba L.) flour

Tannic acid (TA) and green tea extract (GTE) were added to faba bean flour, before and after incubation with polyphenol oxidase (mushroom tyrosinase), and the effect on in vitro iron availability was investigated. The inhibitory effect of TA and GTE was dose dependent, and the in vitro iron availability decreased from 64.5% in the pure faba bean flour to 9.8% (P < 0.05) with the addition of 1 mg of TA 1 g^?1 to faba bean flour. The addition of 5 mg of GTE resulted in low in vitro iron availability as after the addition of 10 mg of TA (11.6% against 10.3% for 1 mg TA). Incubation of the polyphenols with tyrosinase before addition to the faba bean flour significantly increased the in vitro iron availability. The increase in iron availability was significant (P < 0.05) when amounts of 0.2, 0.5 or 1 mg g^?1 TA or GTE added to faba bean flour, respectively, were oxidised, even with the lowest amount of tyrosinase (150 u). Oxidation of 1 mg TA or GTE with 150 u tyrosinase increased the in vitro iron availability from 10.3% to 15.5% and from 19.2% to 26.1%, respectively. At the 300‐u level, the addition of higher amounts of enzyme (from 600 to 900 u) did not have any effect. The results from the study therefore suggest that the oxidation of polyphenols may be a promising way to increase the availability of iron in polyphenol‐containing legume foods.     

Selective separation and characterisation of dual ACE and DPP-IV inhibitory peptides from rainbow trout (Oncorhynchus mykiss) protein hydrolysates

Microwave pretreatment and hydrolysis were applied to rainbow trout (Oncorhynchus mykiss) by-products to produce bioactive peptides with dual in vitro angiotensin-I converting enzyme (ACE) and dipeptidyl-peptidase IV (DPP-IV) inhibitory activities. Peptides were fractionated using the single step electrodialysis with ultrafiltration membrane (EDUF). Concentration of cationic peptides (CP) increased in the recovery solution, reaching 125 μg mL⁻¹ after a 4-h treatment with migration rate of 15.68 ± 2.98 g m⁻² h. CP fractions displayed ACE and DPP-IV I inhibitory properties, with IC₅₀ values of 0.0036 mg mL⁻¹ and 1.23 mg mL⁻¹ respectively. The bioactivity was attributed to the low molecular weight peptides (300–500 Da) recovered. CP exhibited non-competitive inhibition patterns for ACE and DPP-IV, which were dose dependent. These results showed that bioactive peptides can successfully be separated from complex hydrolysate mixtures by EDUF. The fractionated peptides can serve as potential functional food ingredients or nutraceuticals for the management of hypertension and diabetes.     

Evaluation of furosine,lactulose and acid-soluble β-lactoglobulin as time temperature integrators for whipping cream samples at retail in Austria

Three heat load indicators, i.e., furosine, lactulose and acid-soluble β-lactoglobulin, were determined in whipping cream samples purchased from Austrian market (n = 33), as well as commercial samples obtained directly from one Austrian dairy company (one brand, n = 25). Furosine contents were 47.8 ± 14.0, 72.2 ± 36.6, and 172.5 ± 17.7 mg 100 g⁻¹ protein, and β-lactoglobulin contents were 143 ± 91, 195 ± 150, and 89 ± 31 mg L⁻¹ for retailed pasteurised, extended shelf life (ESL), and ultra-high temperature (UHT) cream samples, respectively. Lactulose concentrations (analysed enzymatically) were 29 ± 10, 56 ± 41, and 201 ± 24 mg L⁻¹ for pasteurised, ESL and UHT cream samples, respectively. Linear correlation obtained for furosine and lactulose concentrations indicated that these indicators can reliably assess the heat load of pasteurised, ESL and UHT cream samples, whereas β-lactoglobulin was definitely not appropriate to discriminate between these heating categories.     

Effect of lactic acid bacterial fermentation on amino acids and volatile compounds of pork trimming hydrolysate

The objective of this research was to improve the volatile flavour profile of a pork trimming hydrolysate by lactic acid bacteria (LAB) fermentation. Five probiotic strains and one dairy strain were used. The dominant aliphatic aldehydes (80.90%) in the unfermented hydrolysate were greatly reduced to <15% by converting into respective carboxylic acids and alcohols after fermentation. Strain GG was the only LAB that produced a significant level of succinic acid (1.62 mg mL⁻¹) and ketones (14.92%) (mainly diacetyl and acetoin) in the hydrolysate. Strains 299V and GG showed moderate proteolytic activities as their amino acid content reduced to 126.05 and 219.14 mg per 10 mL compared to the control (316.45 mg per 10 mL) after fermentation, respectively. However, little amino acid-derived volatiles were found in all fermented samples. These findings indicate that LAB fermentation modulates the flavour compounds of pork hydrolysates, which has the potential to be developed to novel flavouring materials.     

Boarfish (Capros aper) protein hydrolysate has potent insulinotropic and GLP-1 secretory activity in vitro and acute glucose lowering effects in mice

The anti-diabetic actions of a boarfish protein hydrolysate (BPH) were investigated in cultured cells and mice. A boarfish (Capros aper) muscle protein hydrolysate was generated using the enzymes Alcalase 2.4 L and Flavourzyme 500 L. Furthermore, the BPH was subjected to simulated gastrointestinal digestion (SGID). BPH and SGID samples (0.01–2.5 mg mL⁻¹) were tested in vitro for DPP-IV inhibition and insulin and GLP-1 secretory activity from BRIN-BD11 and GLUTag cells, respectively. The BPH and SGID samples, caused a dose-dependent increase (4.2 to 5.3-fold, P < 0.001) in insulin secretion from BRIN-BD11 cells and inhibited DPP-IV activity (IC₅₀ 1.18 ± 0.04 and 1.21 ± 0.04 mg mL⁻¹), respectively. The SGID sample produced a 1.3-fold (P < 0.01) increase in GLP-1 secretion. An oral glucose tolerance test (OGTT) was conducted in healthy mice (n = 8), with or without BPH (50 mg/kg bodyweight). BPH mediated an increase in plasma insulin levels (AUC_{(0–120 min),} P < 0.05) and a consequent reduction in blood glucose concentration (P < 0.01), after OGTT in mice versus controls. The BPH showed potent anti-diabetic actions in cells and improved glucose tolerance in mice.     

Bioactive compounds and antioxidant activities of Brazilian hop (Humulus lupulus L.) extracts

Bioactive compounds from Brazilian hop (Humulus lupulus L.) cultivars were extracted by ultrasound and their phenolic profile compared with commercial hop from the USA. The most effective extraction conditions (solution of ethanol 49%, at 52 °C and a solid/liquid ratio of 1 g per 34 mL) for the total phenolic compounds (TPC) were determined using a Central Composite Rotatable Design. The Brazilian hop showed higher content of TPC (33.93 ± 0.67 mg GAE g⁻¹), total flavonoids (54.47 ± 0.10 mg QE g⁻¹) and higher antioxidant activity (ABTS: EC₅₀ 21.29 ± 1.36 μL mL⁻¹; DPPH: EC₅₀ 3.91 ± 0.17 μL mL⁻¹) when compared with the USA hop. The main phenolic compounds present in the extracts were the flavonoids isoquercitrin and quercetin. The antioxidant properties of the Brazilian hop extract had not been reported yet in the literature for this raw material, thus showing potential to be incorporated in polymeric films used as active packaging.     

Inhibition of the in vitro activities of α-amylase, α-glucosidase and pancreatic lipase by yellow field pea (Pisum sativum L.) protein hydrolysates

The aim of this work was to produce yellow field pea protein-derived peptides as inhibitors of α-amylase, α-glucosidase and pancreatic lipase activities. A pea protein concentrate was hydrolysed with alcalase, chymotrypsin, pepsin or trypsin and the hydrolysates separated into different fractions (<1, 1–3, 3–5, 5–10 kDa) by membrane ultrafiltration. Peptide sequence analysis showed that the alcalase hydrolysate had higher levels of di- and tripeptides when compared with the chymotrypsin, pepsin and trypsin hydrolysates. The peptide fractions inhibited α-amylase and α-glucosidase activities at levels that were similar to the unfractionated hydrolysates. The peptides were more active against α-amylase (inhibition at μg level) than α-glucosidase (mg level). In contrast, the fractionated peptides had reduced ability (IC₅₀ >4.2 mg mL⁻¹) when compared with the unfractionated hydrolysate (IC₅₀ <4.2 mg mL⁻¹) to inhibit lipase activity. Enzyme kinetic studies revealed that the peptides reduced α-amylase activity through competitive inhibition. However, inhibition of α-glucosidase activity was non-competitive.     

An integrated sustainable approach for the development of Kyoho skin functional tea

Kyoho (Vitis labruscana) skin is one of the valuable and eco-friendly agricultural waste and a potential source of phenolic compounds. Therefore, we attempted to develop Kyoho skin functional tea and evaluated its nutritional-functional properties as affected by drying temperatures (30, 40, 50 and 60 °C). Kyoho skin functional tea reported negligible protein (0.02 mg g⁻¹), fat (0.04–0.19%) and calories (0.36–0.70 cal g⁻¹). Total phenolic and flavonoid contents ranged from 0.25 to 0.56 mg GAE mL⁻¹ and 0.03 to 0.19 mg QE mL⁻¹, respectively. Kyoho skin functional tea showed functional properties including antioxidant activity (63.33–79.78%) and anthocyanins (0.25–0.34 mg per 100 mL). The sensory evaluation of Kyoho skin functional tea (dried at 40 °C) rated as acceptable (>6) with attractive colour (>6). Overall, these findings recommended the possibility of using Kyoho skin to develop functional teas, which may strengthen the global beverage industries.