EVALUATION OF DRUM-DRIED MEALS PREPARED FROM SPLIT BEANS (PHASEOLUS VULGARIS L.): PROTEIN QUALITY AND SELECTED ANTINUTRITIONAL FACTORS

The effects of aqueous extraction and enzymatic pretreatments on the in-vitro and in-vivo protein digestibilities and antinutritional factors of drum-dried bean (Phaseolus vulgaris L.) meals were evaluated. The apparent protein digestibility of beans subjected to a 60C/30 min aqueous extraction was approximately 86% which is comparable to or greater than what is reported for canned beans. Likewise, the antinutritional factors Trypsin Inhibitor Activity (TIA) and lectins were either significantly reduced or inactivated by the drum-drying process, as further supported by in-vivo rat feeding studies. The drum-drying process can be a suitable alternative process for the traditional commercial canning of dry beans, providing economic utilization of dry split beans. Further, the resultant DDBMs find broader application as an ingredient in convenient and nutritious food formulations such as weaning foods, baked and pasta products.     

MINERAL CONTENTS IN SEED COAT AND CANNING QUALITY OF SELECTED CULTIVARS OF DARK RED KIDNEY BEANS (PHASEOLUS VULGARIS L.)

Three different dark red kidney bean (Phaseolus vulgaris L.) cultivars (cvs. 85, 453 and Nickols) grown in Wisconsin were studied to investigate the correlations of the mineral contents in the seed coat and seed coat splits in the canned beans. In the canned product, highly significant differences ( P ≤0.01) in percentage of split seed coats were observed among the three cultivars studied. Canned cultivar 85 significantly showed fewer seed coat splits than the other two cultivars. Significant negative correlations were observed between the percentage of seed coat splits and sodium (r = ? 0.89, P ≤ 0.01), calcium ( r = ? 0.74, P ≤ 0.01) and iron (r = ? 0.79, P ≤ 0.05) contents in the seed coat. This study suggested that the mineral content of the seed coat of kidney beans may play important roles in the integrity of the seed coat during thermal processing.     

INHIBITION OF HELICOBACTER PYLORI BY PHENOLIC EXTRACTS OF SPROUTED PEAS (PISUM SATIVUM L.)

Infection by Helicobacter pylori is associated with gastric and duodenal ulcers. Conventional treatments to eradicate it have side‐effects such as diarrhea and dizziness. The excessive use of antibiotics could also lead to antibiotic‐resistant bacteria. The use of plant phenolic phytochemicals can be an alternative because of their health benefits due to both antioxidant activity and antimicrobial activity. The pea (Pisum sativum), the world's second most important pulse crop, produces phenolic phytochemicals with antimicrobial potential. Because the synthesis of phenolic compounds increases with stress, we investigated the anti‐H. pylori effectiveness of extracts from pea sprouts, germinated in the dark condition following treatment with either distilled water or acetyl salicylic acid. The peas were germinated for 8 days and the sprouted samples were measured for total soluble phenolic content, antioxidant and guaiacol peroxidase activity. Subsequently, the sprout extracts were tested for anti‐H. pylori activity using the agar diffusion method and the effective dose was determined based on phenolic content. The results showed that both acetyl salicylic acid‐treated and untreated pea sprouts at days 5 and 8 had anti‐H. pylori activity. The minimum volume for inhibition was 50 μL of extracts. The inhibitory effects were dose dependent. From this study, the potential to use natural phenolic phytochemicals from pea sprouts to control H. pylori was found to be promising. This provides a strategy and foundation to design legume phenolics as functional ingredients against H. pylori.     

THE LECTINS AND LECTIN-LIKE PROTEINS OF TEPARY BEANS (PHASEOLUS ACUTIFOLIUS) AND TEPARYCOMMON BEAN (PHASEOLUS VULGARIS) HYBRIDS

High levels of lectin activity were found in sixty cultivated and ten wild tepary (Phaseolus acutifolius) accessions. No lectin deficient varieties were observed and all examples studied contained both the phytohemagglutinin-E and L-like lectins previously described (Pusztai et al. 1987). There appeared to be no obvious differences between the wild and cultivated forms of the tepary lectins and all teparies studied contained lectin-like proteins in addition to the tepary lectins. One of the lectin related proteins (40 Kdalton subunit) was present in all teparies and may be comparable to arcelin, a lectin found in certain wild accessions of Phaselus vulgaris. All wild teparies contained a lectin related polypeptide of about 34 Kdaltons which appears to distinguish the wild teparies from the cultivated forms. Three tepary-common bean hybrids were examined and one hybrid was found to be expressing both tepary and common bean lectin genes.     

QUANTIFICATION AND SOME CHEMICAL AND BIOCHEMICAL CHARACTERIZATION OF NITROGENOUS SUBSTANCES FROM VARIETIES OF COMMON BEANS (PHASEOLUS VULGARIS, L.).

Crude protein, extracted protein, and nonprotein nitrogenous substances were quantified in 55 varieties of common dry beans. Crude protein (% N x 6.25) on a dry basis varied from 23.01 to 35.22%, with a mean value of 28.51%. Methionine varied from 0.40 to 1.73% of the crude protein with a mean value of 0.80%. The ratio of globulin/albumin ranged from 1.00 to 3.31. Thirty percent of the total nitrogen was of low MW and was lost in the dialysis (MW cut off 8,000 daltons). Electrophoretic patterns (PAGE) revealed from 3 to 11 bands in the globulin fraction and 4 to 11 in the albumin fraction. Trypsin and chymotrypsin inhibitory activity was much higher in the albumin fraction than in the globulin fraction. The globulin fraction from most of the varieties was more inhibitory against trypsin than chymotrypsin. On the other hand, in the albumin fraction of the majority of the varieties the activity was stronger against chymotrypsin. Hemagglutination titer for 57 varieties ranged from 1024 to 32. Eight varieties had titers of 1024 and only four had titers of 32.     

THE EFFECT OF PHYTATE AND FIBER CONTENT ON COOKING QUALITY IN FABA BEANS

Seventy-six faba bean lines were analyzed for their phytic acid content in the whole seeds and in the cotyledons. The fiber content was also determined in 17 Faba bean lines. The seed weights; % testa weight-of the seeds; and % moisture uptake (water imbibition) after overnight soaking in distilled water or increasing concentrations of EDTA solutions were measured and recorded. The relation between the above mentioned dependent variables and the cooking time for seed softening (min.) in 76 faba bean lines was studied and simple and multiple correlation coefficients were computed with a total of 70 operations. Significant correlation coefficients were found between phytic acid content in the cotyledons, % testae weight of the seeds; moisture uptake after soaking the seeds in distilled water overnight and cooking time for 50% softening (min). The faba bean lines 606/ 303; 606/ 308, 608/ 334, 609/ 350, proved to be of excellent cooking quality, since their cooking time for 50% seed softening did not exceed 10 min.     

EFFECTS OF COOKING CONDITIONS AND POST-PREPARATION PROCEDURES ON THE QUALITY OF BATTERED FISH PORTIONS

The effects of different cooking conditions and postpreparation handling on quality of battered fish portions for fast food services were investigated. As the frying temperature increased from 300 to 400°F (149–204°C), the cooking time of battered fish portions decreased from 276 to 202 s. Crude lipid content in the batter decreased as the temperature of the frying oil increased. Holding times (10, 20 min) affected crude lipid contents of the batter depending on the cooking temperature and were lower than an unheld product. Crude lipid contents in the fish fillets were generally higher after frying by 2–3%. The crude lipid uptake by the batter coating differed significantly for the three frying shortenings (partially hydrogenated soybean, V-S oil; animal fat-vegetable blend, A-V Fat; and vegetable-palm oil blend, V-P oil;) compared in this study. This finding contrasts with previously published results. The amount of crude lipid uptake by the fish varied with shortening type and holding times. No consistent trend was observed to occur. Peroxide values increased after 3 days in the V-S Oil and A-V Fat. Flavor scores on battered fish portions cooked in V-S Oil, V-P Oil, and A-V Fat were not statistically different immediately after cooking and after holding for 10- +20-min on the first day. By the second day, differences were observed among the three shortenings. Both shortening type and postpreparation holding times affected the perceived greasiness.     

PURIFICATION AND COMPOSITION OF THE TRYPSIN-CHYMOTRYPSIN INHIBITORS OF PHASEOLUS VULGARIS L. VAR ROSINHA G2

Three trypsin-chymotrypsin inhibitors were purified to homogeneity from Phaseolus vulgaris L. var Rosinha G2 (Brazilian pink beans). At least one more trypsin-chymotrypsin inhibitor was present. Purfication was achieved by fractionation into albumin and globulin fractions based on differential salt/water solubilities, affinity chromatography on trypsin-Sepharose, DEAE-cellulose chromatography and CM-cellulose chromatography. Purity of the inhibitors was determined by rechromatography, combining ratios with trypsin and by disc gel electrophoresis. The isolated inhibitors were very similar, although distinguishable, by amino acid analysis. They had no tryptophan and valine, one residue of methionine, low glycine, alanine, leucine and tyrosine contents and high levels of serine, threonine, proline and half-cystine (18.5 to 21.0 residues per molecular weight of 20,000). They also contained a low amount of carbohydrate (one equivalent of mannose per 20,000 g protein).     

THE MOLECULAR WEIGHT OF α-AMYLASE INHIBITOR FROM WHITE BEAN cv 858B (PHASEOLUS VULGARIS L.) IS 56 kDa, NOT 20 kDa

The molecular weights (M_rs) of α-amylase inhibitors (αAIs)fiom 18 (Ah) bean cultivars estimated by Superose 12 gelfiltration chromatography were 22–62% smaller than those determined by Sephadex G-100 gel filtration and by polyacrylamide gel electrophoresis (PAGE) methods. αAI-4 from WKB cultivar 858B was purified and the Mr was shown to be 51.0 kDa based on Sephadex G-100 gel filtration chromatography and by PAGE. A M_r for aAI-4 of 56.714 kDa was determined by laser-assisted time-of-flight mass spectrometry and appears to be the true M_r of the mature glycosylated active aAI-4. The results show that Superose 12 gelfiltration chromatography is not usefulfor M_r determination of some proteins. Sodium dodecyl sulfate electrophoresis (SDS-PAGE) showed that the 56.7 kDa aAI-4 molecule dissociated into 45.0, 33.6,15.2 and 12.4 kDa submolecules, with only the two small subunits, a and β, present at high SDS concentration. This provides evidence that the aAI-4 molecules composition is α₂β².     

QUALITY OF PRECOOKED VACUUM-PACKED POTATOES (Solanum tuberosum L.) IN RELATION TO COOKING METHODS AND OXYGEN PERMEABILITY OF THE PACKAGING MATERIAL

Precooked vacuum-packed potatoes are widely used in catering. The influence of different processing temperatures on texture kinetics of water and steam cooked vacuum-packed potatoes was studied. At temperatures above 90C the initial decline in cohesion of steam cooked vacuum-packed potatoes was followed by an increase in cohesion when processed for more than 30 min. Preheating of vacuum-packed potatoes at 70C and 75C increased their cohesion and thereby firmness. Steam cooked vacuum-packed potatoes processed in multilayer barrier pouches having a low oxygen permeability (0.9 cm³/m²/24h/atm) compared with standard pouches had a more intense and stable yellow surface color, as well as they developed significantly less off-flavor after storage. The oxygen permeability of the pouches had no effect on the content of vitamin C, neither during processing nor after storage. The vitamin C content of steam cooked vacuum-packed potatoes was unaffected by processing time.