A soybean cultivar lacking lipoxygenase 2 and 3 has similar calcium bioavailability to a commercial variety despite higher calcium absorption inhibitors

ABSTRACT:  The aim of this study was to evaluate calcium bioavailability of a new soybean variety without 2 lipoxygenases with better taste and flavor than a commercial variety containing all 3 isozymes. Using the femur ⁴⁵Ca uptake method, calcium absorption from a new Brazilian variety, UFV-116, was compared to a common Brazilian variety, OCEPAR 19. Male Sprague–Dawley growing rats weighing 150 to 170 g (10/group) received test meals of whole fat soy flour prepared from UFV-116 or OCEPAR-19 seeds labeled with 10 μCi of ⁴⁵Ca. Femurs were removed after 48 h for determination of ⁴⁵Ca uptake. Calcium fractional absorption was equivalent between the 2 varieties. The higher oxalate:calcium molar ratio and the higher content of oxalate and phytate ( P < 0.05) found in the UFV-116 variety did not affect calcium absorption. Therefore, the new variety is a comparable source of high bioavailable calcium.     

Chemical composition of a soybean cultivar lacking lipoxygenases (LOX2 and LOX3)

The nutrient, phytic acid, oxalate, trypsin inhibitors and isoflavones composition of a whole soy flour produced from a new cultivar (UFV-116), lacking lipoxygenases 2 and 3, compared to a conventional cultivar (OCEPAR-19) were determined. Protein and dietary fibres (total, soluble and insoluble) were similar for both cultivars. OCEPAR-19 was higher in lipids and UFV-116 in ash content (p < 0.05). Indispensable, dispensable and total aminoacid as well as Ca, K and Mg were higher for UFV-116. This cultivar also showed higher levels of phytic acid, oxalate and trypsin inhibitors (p < 0.05). Total saturated and unsaturated fatty acids were similar between them. However, palmitic and linoleic acids were higher for UFV-116 and stearic, α-linolenic and oleic acids for OCEPAR-19 (p < 0.05). The higher concentration of isoflavones in UFV-116 (p < 0.05) could provide better benefit for human health. Experimental studies are necessary to evaluate health effects of this new soybean cultivar.     

Optimization of Gluten-Free Bread Prepared from Cornstarch, Rice Flour, and Cassava Starch

ABSTRACT: The proportions of cornstarch, cassava starch, and rice flour were optimized for production of gluten-free bread (with 0% and 0.5% soy flour) to maximize specific volume (Y₁,Y₁'), crumb-grain score (Y₂,Y₂'), and bread score (Y₃,Y₃'). A central composite design involving cornstarch/cassava starch ratio (X₁) and rice flour/cassava starch ratio (X₂) was used, and 2nd-order models for Y₁ and Y₁' were employed to generate response surfaces. The maxima of response surfaces for crumb-grain score and bread score indicate that optimal gluten-free bread can be prepared from 74.2% cornstarch, 17.2% rice flour, and 8.6% cassava starch. Addition of soy flour at the 0.5% level also improved bread texture.     

Sensory Trial to Assess the Acceptability of Zinc Fortificants Added to Iron-fortified Wheat Products

ABSTRACT: We studied the sensory acceptability of products made from iron- and zinc-fortified wheat flour. Subjects tasted bread and noodles fortified with 30 mg of iron as FeSO₄/kg flour or iron and either 60 or 100 mg of zinc/ kg flour as either ZnSO₄ or ZnO. Subjects rated their degree of liking (DOL) for flavor, texture, and overall acceptability, using a 9-point hedonic scale. All products were generally well liked, although noodles fortified with iron and ZnO had slightly lower DOL scores than noodles fortified with iron only or iron and ZnSO₄. We conclude that foods prepared from zinc-fortified wheat flour should be well accepted.     

SOLUBILIZATION AND FUNCTIONAL PROPERTIES OF MOTH BEAN (VIGNA ACONITIFOLIA (Jacq.) Marechal AND HORSE GRAM (MACROTYLOMA UNIFLORUM (Lam.) Verdc. PROTEINS

Horse gram and moth bean seeds contained 23.6% and 21.9% protein (N x 6.25), respectively. Both the legumes are rich sources of iron. The iron contents in horse gram and moth beans were 11.0 and 9.6 mg/100 g, respectively. NaCl at 10% (w/v) and Na₂CO₃ at 0.5% (w/v) were found to be effective in extracting 89% and 80% of moth bean and horse gram proteins from defatted flour The minimum solubility of horse gram proteins from defatted flour was at pH 4.0 whereas proteins from moth bean exhibited minimum solubility at pH 4.5. The water and oil absorption, and foaming capacities in case of horse gram and moth bean flours were 2.0 g/g and 2.2 g/g, 23.0% and 2.0 g/g, 1.6 g/g, 27.6%, respectively.     

Effect of natural fermentation on in vitro zinc bioavailability in cereal–legume mixtures

There is increasing concern about zinc availability from cereal-based vegetarian diets and the need to improve its native bioavailability. Effects of natural fermentation on zinc availability were assessed by in vitro assay with a ⁶⁵Zn extrinsic tag on four cereals (rice, wheat, sorghum and pearl millet), four decorticated legumes (red gram, bengal gram, green gram and black gram) and their 16 binary combinations. Fermentation significantly increased zinc solubility (2–28%) and zinc uptake by intestinal segment (1–16%). Two-way ANOVA indicated significant effects of combinations on zinc solubility but not on zinc uptake in both fermented and unfermented states. Levels of phytate-P were reduced while titratable acid and ascorbic acid levels were increased by fermentation. However, tannins were unchanged.     

CHARACTERIZATION OF MODEL NITROSYLHEME PIGMENTS WITH VISIBLE, INFRARED AND 15N FOURIER TRANSFORM NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY

Synthetic pigments that model the organic-soluble pigment in heat-processed cured ham were characterized with infrared (IR) and ¹⁵N nuclear magnetic resonance (NMR) spectroscopy. The two pigments synthesized were ¹⁵N nitrosyl (protoporphyrinato- IX) iron (II), or Fe^II PP¹⁵ NO, and ¹⁵N dinitrosyl (protoporphyrinato-IX), or Fe^II PP(¹⁵NO)₂. An NMR spectrum was obtained only for the Fe^II PP¹⁵ NO. The NMR spectrum consisted of a single peak + 1.78 ppm from the Na¹⁵ NO³ and –6.8 from the CH₃NO₂ reference. The IR spectrum included a single NO symmetric stretch at 1801 cm⁻¹. The visible spectrum of Fe^II PPNO did not match the visible spectrum of ham extracts, while it did with FE^II PP(¹⁵NO)₂. An unequivocal structural assignment of Fe^II PP¹⁵ NO was made, but longer NMR runs may be necessary to obtain a spectrum and unequivocal structural assignment of Fe^II PP(¹⁵ NO)₂.     

Bioavailability of Elemental Iron Powders in Bread Assessed with an In vitro Digestion/Caco-2 Cell Culture Model

ABSTRACT: Iron fortification of staple foods is arguably the most widely used strategy for increasing the iron intake of populations. Although FeSO₄ is a bioavailable form of iron, elemental iron powders are often used to fortify products with a long shelf-life, such as wheat flours, to avoid problems associated with the reactive nature of FeSO₄. Therefore, the objectives of this study were to compare the bioavailabilities of elemental iron powders manufactured with different production methods in wheat flour breads and to determine the effects of added ascorbic acid and baking, using an in vitro digestion/Caco-2 cell culture model. Two types of wheat flour (low-extraction and high-extraction) were fortified with 10 different commercial elemental iron powders and baked into breads. Iron bioavailabilities from the resulting breads, with and without added ascorbic acid, were evaluated using FeSO₄ as the control. Depending on the type of wheat flour, bioavailabilities of several powders were comparable to FeSO₄, but there was no consistent trend as to which production method produced the most bioavailable powder. In general, ascorbic acid enhanced, whereas the baking process reduced iron bioavailability from bread. Our results suggest that some elemental iron powders are potential alternatives to FeSO₄. Human studies are warranted before any of these powders are selected for national fortification programs.     

Peanut protein concentrate: Production and functional properties as affected by processing

Peanut protein concentrate (PPC) was isolated from fermented and unfermented defatted peanut flour by isoelectric precipitation and physical separation procedures. PPC was dried by spray or vacuum drying. PPC powders from each drying technique were evaluated for proximate composition and functional properties (protein solubility, water/oil binding capacity, emulsifying capacity, foaming capacity and viscosity) along with defatted peanut flour and soy protein isolate as references. PPC contained over 85% protein versus 50% protein in the defatted peanut flour used as raw material for PPC production. PPC had a solubility profile similar to that of peanut flour, with minimum solubility observed at pH 3.5–4.5 and maximum solubility at pH 10 and higher. Roasting of peanut reduced all functional properties of defatted peanut flour while fermentation had the reverse effect. The type of drying significantly affected the functional properties of PPC. Spray dried PPCs exhibited better functional properties, particularly emulsifying capacity and foaming capacity, than vacuum oven dried PPC. Spray dried PPCs also showed comparable oil binding and foaming capacity to commercially available soy protein isolate (SPC). At equivalent concentrations and room temperature, PPC suspension exhibited lower viscosity than soy protein isolate (SPI) suspensions. However, upon heating to 90 °C for 30 min, the viscosity of PPC suspension increased sharply. Results obtained from this study suggest that the PPC could be used in food formulations requiring high emulsifying capacity, but would not be suitable for applications requiring high water retention and foaming capacity. PPC could be a good source of protein fortification for a variety of food products for protein deficient consumers in developing countries as well as a functional ingredient for the peanut industry. The production of PPC could also add value to defatted peanut flour, a low value by-product of peanut oil production.     

Organoleptic and nutritional evaluation of wheat breads supplemented with soybean and barley flour

Supplementations of soy (full fat and defatted) and barley flours to wheat flours at 5, 10, 15 and 20% levels were carried out to test the effects on organoleptic and nutritional evaluation of the supplemented bread. Additions of 15% barley flour, 10% soy flour (full fat and defatted), 15% barley plus full fat soy flour and 15% barley plus defatted soy flour to wheat flour produced acceptable breads. However, substitution of soy (full fat and defatted) and barley flours to wheat flour separately and in combinations at 20% levels did not produce organoleptically acceptable bread. Various nutritional parameters, such as protein, fat, total lysine, protein digestibility (in vitro), sugars, starch digestibility (in vitro), total and available minerals, antinutrients, dietary fibre and β-glucan were determined in supplemented and control bread. Increasing the level of substitution from 5 to 10% of full fat and defatted soy flour to wheat flour significantly (P<0.05) increased protein (from 12.1 to 13.7 and 12.4 to 13.8%), lysine (from 2.74 to 3.02 and 2.76–3.05 mg/100 g protein) and total calcium (from 70.2 to 81.4 and 71.9–81.8 mg/100 g) contents. However, there was also an increase in phytic acid (238–260 and 233–253 mg/100 g), polyphenol (324–331 and 321–329 mg/100 g) and trypsin inhibitor activity (193–204 and 193–198 TIU/g). When barley flour was substituted separately, and in combinations, with full fat and defatted soy flour up to 15%, this significantly increased the contents of protein, total lysine, dietary fibre and β-glucan. It may be concluded that breads supplemented with barley and defatted soy flour, up to a 15% level, are organoleptically and nutritionally acceptable.     

EFFECT OF ELECTRICAL STIMULATION ON KILLING SALMONELLA TYPHIMURIUM IN VARIOUS SALT SOLUTIONS

Electrical stimulation was evaluated as a method to kill Salmonella typhimurium in various salt solutions at different concentration . Salmonella typhimurium at 2 × 10⁵ CFU/ml was treated at 22–24C for 60 min in each salt solution using electricity at 10 mA/cm² current, 1 kHz frequency, and 50% duty cycle. Samples taken at various times were serially diluted, plated on tryptic soy agar and xylose lysine desoxycholate agar, and incubated at 37C for 18–24 h. To detect injured cells, samples were also pre-enriched in buffered peptone water at 37C for 4–5h before being plated. Results indicated all salmonellae were electrically killed at 5 min in NaCl, at 30 min in NaNO₃, and at 45 min in NaC₂H₃O₂ at 0.15 and 0.015 M concentrations. Salmonellae were also killed at 45 min in Na₃PO₄ and at 60 min in Na₂CO₃ at 0.0015 M concentration by electricity in combination with high pH .     

Bioavailability to rats of iron from fortified grain amaranth flour

In this study, fortified and unfortified grain amaranth seed flour and FeSO₄ fortified casein diet as control were evaluated for their iron bioavailability. NaFeEDTA, ferrous fumarate, and FeSO₄-fortified grain amaranth were fed to Sprague Dawley weanling male rats. Iron intake, Hb Fe gain, Fe availability and binding capacity, serum iron, non-haem liver iron and relative biological value (RBV) were determined and values compared with FeSO₄-fortified casein control; all were improved greatly by fortification.
Relative biological values (RBV) were 0.40, 1.55, 1.75, 1.67 and 1.00 for animals receiving unfortified amaranth diet, those fed diet fortified with NaFeEDTA, ferrous fumarate, FeSO₄ and casein fortified with FeSO₄ respectively. RBV of the unfortified cereal was 40% of control suggesting perhaps low iron absorption from the amaranth cereal.
Based on the results of this study, amaranth cereal is ideal as a food vehicle for iron fortification. The iron fortificant of choice is ferrous fumarate.     

Carbon-centered radicals in isolated soy proteins

ABSTRACT:  Solid-state electron paramagnetic resonance (EPR) spectroscopy of commercial samples of isolated soy proteins (ISP) revealed a symmetrical free-radical signal typical of carbon-centered radicals ( g = 2.005) ranging from 2.96 × 10¹⁴ to 6.42 × 10¹⁴ spins/g. The level of free radicals in ISP was 14 times greater than similar radicals in sodium caseinate, 29 times greater than egg albumin, and about 100 times greater levels than casein. Nine soy protein powdered drink mixes contained similar types of free radicals up to 4.10 × 10¹⁵ spins/g of drink mix, or up to 6.4 times greater than the highest free-radical content found in commercial ISP. ISP samples prepared in the laboratory contained trapped radicals similar to the levels in commercial ISP samples. When ISP was hydrated in 2.3 mM sodium erythorbate or 8.3 mM L-cysteine, frozen and dried, the level of trapped free radicals increased by about 17- and 19-fold, respectively. The ESR spectrum of defatted soybean flakes contained overlapping signals from the primary free-radical peak ( g = 2.005) and a sextet pattern typical of manganese-II. The manganese signal was reduced in the laboratory ISP and very weak in the commercial ISP.     

Elimination of Listeria monocytogenes in soft and red smear cheeses by irradiation with low energy electrons

Soft and red smear cheeses are frequently contaminated by Listeria monocytogenes , sometimes at relatively high concentration (< 10⁵ CFUg^-1). This bacterium is radiosensitive (D₁₀ value of approximately 0.45 kGy) but irradiation of the whole cheese by X-rays induced off-flavours when the dose exceeded 1.0 kGy. Irradiation could be effective in eliminating L. monocytogenes only from lightly contaminated cheeses (> 10²CFU g^-1).
L. monocytogenes appears only in the rind (where the pH is greater than 6.3) and never grows in the core of the cheese. Under these conditions, a specific irradiation of the rind after ripening, with a low-energy electron beam at relatively high doses (up to 3.0 kGy), allows the total elimination of L. monocytogenes in heavily contaminated samples (10⁵-10⁶ CFU g^-1) without noticeable modifications of the organoleptic properties of the cheese.     

Effect of Iron on the Color of Barley and Other Cereal Porridges

ABSTRACT: Iron added as ferrous sulfate at 500 mg*kg⁻¹ to rice, oats, whole grain wheat, or proanthocyanidin-free barley porridge caused significant changes in the Hunter "L", "a", and "b" values but the visual appearance of these porridges remained satisfactory. Porridge made with normal barley flour fortified with 500 mg*kg⁻¹ of iron developed an unappealing gray color with ferrous sulfate, ferrous fumarate, or electrolytic iron, 3 salts differing in solubility. At 100 and 250 mg*kg⁻¹ of iron, the discoloration of normal barley porridge was less pronounced, but still objectionable. When fortified with 50 mg*kg⁻¹ of iron, normal barley porridge had a slight color change but was not noticeably gray. Thus barley-containing foods can be fortified with a soluble iron compound at the level of iron used in enriched flour and similar cereal-grain foods for the general population without developing an unattractive color.     

Processing, Functional, and Nutritional Properties of Okra Seed Products

Okra full-fat flour, defatted flour, protein concentrate, and protein isolate were prepared from whole okra seeds (Spineless Green Velvet variety). Results of proximate analysis, amino acid profiles, in vitro protein digestibility, and calculated protein efficiency ratios (C-PER) indicated that okra products have significant potential as a viable new protein source. C-PER of okra products ranged from 2.16–2.22. Protein solubility indicated that these okra products were generally more soluble than commercial soy products. Emulsion capacity and viscosity of okra products were significantly lower than those for soy products. Overall, foam stability of soy products was consistently higher than that for okra products.     

Effect of irradiation and modified atmosphere packaging on the microbiological safety of minced pork stored under temperature abuse conditions

The safety of irradiated pork packed in 25% CO₂:75% N₂ and stored at abuse temperature (10 or 15°C) was assessed by inoculation studies involving Salmonella typhimurium, Listeria monocytogenes, Escherichia coli, Yersinia enterocolitica and Clostridium perfringens . Irradiation to a dose of 1.75 kGy reduced pathogen numbers to below the detection limit of 10² cells g^-1. When higher inoculum levels were used (10⁶ cells g^-1) irradiation at 1.75 kGy reduced pathogen numbers by 1 –>5 log₁₀ cycles depending on strain. Clostridium perfringens was the most resistant, and Y. enterocolitica the most sensitive of the pathogens studied.
In all cases when high numbers (10⁶ to 10⁷g^-1) of spoilage and/or pathogenic bacteria were present initially on the pork the meat appeared spoiled, and although irradiation reduced the number of microorganisms, the meat was still unacceptable from a sensory viewpoint after treatment.
It was concluded that the microbiological safety of irradiated, modified atmosphere packaged (MAP) pork is better than that of unirradiated MAP pork.     

IN VITRO COMPARISON OF ANAEROBIC AND AEROBIC GROWTH RESPONSE OF SALMONELLA TYPHIMURIUM TO ZINC ADDITION

Zinc supplemented diets have been used to provide zinc as a nutrient and higher concentrations have been used to induce molt in laying hens. It is not known if the zinc in these diets would inhibit Salmonella spp growth. This study examines the effects of zinc compounds on the growth of S. typhimurium poultry isolate under aerobic and anaerobic conditions. The aerobic growth response of S. typhimurium was determined either in tryptic soy broth (TSB) or minimal (M9) broth containing five different concentrations (0.67, 2.01, 3.35, 4.69, and 6.03% [wt/vol]) of either Zn acetate [Zn(C₂H₂O₂)₂2H₂O] or Zn sulfate [ZnSO₄7H₂O] while anaerobic growth response was determined in M9 broth with or without reductants (L-cysteine hydrochloride [C₃H₇NO₂SHCl], and sodium sulfide [Na₂S 9H₂O]). Aerobic growth rates inhibited (P < 0.05) by Zn acetate than by Zn sulfate in TSB medium. The Zn source and concentration decreased (P < 0.05) aerobic growth response of S. typhimurium poultry isolate in M9 medium. The growth rates of S. typhimurium under anaerobic growth conditions were less responsive to Zn salts but were generally lower (P < 0.05) in the presence of reductant than in the absence of reductants at each concentration of Zn compound. The results in this study provide evidence that Zn may inhibit S. typhimurium under in vitro aerobic or anaerobic atmospheric conditions and S. typhimurium grows less optimally under anaerobic growth conditions.     

Rapid Measurement of Phytate in Soy Products by Mid-infrared Spectroscopy

ABSTRACT: The rapid measurement of phytate from soybean and its products, such as soy flour, defatted meal, soymilk, and tofu, was investigated using Fourier transfer infrared spectroscopy (FT-IR) with an attenuated total refraction accessory. The phytate, separated from protein by trichloroacetic acid (TCA), was precipitated completely by the addition of calcium, pH > 7.0, even in the presence of TCA. The precipitate was dissolved in citrate buffer (pH 6.0) and then used for infrared measurement. The absorbance at 1070 cm⁻¹ correlated well the phytate content of the each sample. The measurement of phytate can be done rapidly by FT-IR with an ATR accessory and gives reproducible values.     

APPLICATION OF CHLORINE TO REDUCE POPULATIONS OF ESCHERICHIA COLI ON BEEF

The effects of chlorine against 2 strains of E. coli attached to the surface of beef carcass tissue (BCT) were examined using a model carcass washer. Lean and adipose BCT with approximately 5 log ₁₀ CFU/cm ² E. coli bacteria were spray-treated with water and sodium hypochlorite (NaOCl) to give chlorine concentrations of 50, 100, 250, 500, or 800ppm, incubated for 24 h, 4C, and E. coli populations enumerated. Spray treatments with water did significantly (P < 0.05) reduce the bacterial populations of either organism attached to lean or adipose BCT, as compared to populations of controls; however, reductions were less than 0.60 log ₁₀ CFU/cm ². Treatments with 500 and 800 ppm chlorine against E. coli ATCC 25922 attached to BCT resulted in the greatest reductions of 1.22 and 1.28 log ₁₀ CFU/cm ², respectively. At 800 ppm chlorine , E. coli O157:H7 ATCC 43895 attached to BCT was reduced by 1.04 log ₁₀ CFU/cm ², whereas spray treatments with 50, 100, 250, and 500 ppm chlorine resulted in reductions of < 1 log ₁₀ CFU/cm ². Spray treatments with chlorine from sodium hypochlorite solutions reduced populations of E. coli, however, these reductions were not sufficient to completely inactivate the bacteria attached to red meat .