Effects of dried okra fruit (Abelmoschus esculentus L.) powder on growth, carcass characteristics, blood indices, and meat quality of stored broiler meat.

The present study investigated the impacts of dried okra fruit powder (DOFP), used as a natural feed supplement, on growth, carcass, blood, and meat quality parameters of broilers. A total of 240 unsexed, one-week-old chicks were randomly allotted to 4 equal groups with 6 replicates in each group (i.e., 10 birds/replicate). The dietary treatments consisted of the basal diet as control, and 3 DOFP groups, supplemented with 1.0, 2.0, and 3.0 g DOFP/kg feed, respectively. The results showed that the highest values of live body weight and body weight gain were observed in the group with 1.0 g of DOFP/kg of feed during the fifth week of age and between 1 and 5 wk of age, respectively. During 1 to 3 wk of age, daily feed consumption of chicks fed DOFP-supplemented diets increased numerically with increasing DOFP levels. Dietary treatments significantly depressed liver, thigh, and dressing fat percentages. Chicks fed the diet containing 1.0 g of DOFP/kg of feed had the lowest values for serum urea and creatinine compared with the other treatment group. In addition, the concentration of liver enzymes decreased with increasing DOFP levels, except for the groups fed 3.0 and 1.0 g of DOFP/kg of diet. Oxidative rancidity of broiler meat samples containing DOFP in their diets was lower than that of the control samples, throughout the storage period. It can be concluded that DOFP is a useful phytogenic additive, which can lower the percentage of abdominal fat of the carcass, as well as alanine aminotransferase, urea, and creatinine in the blood. Furthermore, all sensory characteristics of the meat were improved by the addition of DOFP to broiler diets. It could be concluded that DOFP can be used as a natural supplement in broiler diets for improving growth performance and reducing abdominal fat, blood creatinine, and urea.

Impeding Bacillus spore germination in vitro and in milk by soy glycinin during long cold storage.

This paper presents a study of the magnitude and mechanism of impeding the emergent spore germination of Bacillus subtilis (non-hemolytic strain) and Bacillus licheniformis (hemolytic strain) under the action of soybean glycinin and its basic subunit (BS). Incubating B. licheniformis spores with 100 µg/ml of glycinin or BS at 35°C for 24 h totally prevented the hemolytic activity associated with the emergent vegetative cells on blood agar during 3-5 days of incubation at 35°C in contrast to the control. Glycinin and BS (100 µg/ml) also resulted in the leakage of 70 and 73% of the initially germinating spore contents of A260 absorbing materials of the two bacterial species after 2 h of incubation at 35°C, respectively. Increasing the concentration of glycinin and BS up to 400 µg/ml increased the germinating spore leakage to 83 and 88%, respectively. Spore germination in Muller Hinton Broth containing glycinin and BS (100 µg/ml) was practically nil after 4 days of incubation at 35°C. Supplementing milk preheated at 80°C/5 min with both glycinin and BS kept the final vegetative cell counts down to about 30 and 20% of the corresponding control, respectively, after 50 days of storage at 4°C. Both light, and transmission electron, microscopy images revealed significant morphological and structural distorting changes in BS-treated spores of B. licheniformis.

Preservative action of 11S (glycinin) and 7S (ß-conglycinin) soy globulin on bovine raw milk stored either at 4 or 25 °C.

Considerable inhibitory antibacterial actions were exerted by the soybean 11S subunit comparable with nisin on the proliferation of total viable count, Pseudomonas count and Enterobacteriaceae count in bovine milk stored at 4 or 25 °C for 30 d and 48 h, while 7S and lysozyme were much less effective. The maximum magnitudes of bacterial reduction by 11S and nisin were in the range 2-4 log CFU/ml. The proliferation of 3 pathogenic bacteria (Listeria monocytogenes, Salmonella Enteritidis and Escherichia coli O157:H7) artificially inoculated into raw milk stored at 4 or 25 °C were particularly and significantly (P<0.05) reduced by 11S subunit and nisin (0.5% w/v), but only slightly by 7S and moderately by lysozyme. Lactose consumption, acidity development and casein degradation during storage of bovine raw milk were attenuated during storage at 4 or 25 °C and sensorial traits were better maintained by supplementation with 11S (0.5% w/v). 11S subunit may be used a safely food preservative, if permitted.

In vitro and in situ antimicrobial action and mechanism of glycinin and its basic subunit.

Glycinin, basic subunit and ß-conglycinin were isolated from soybean protein isolate and tested for their antimicrobial action against pathogenic and spoilage bacteria as compared to penicillin. The three fractions exhibited antibacterial activities equivalent to or higher than penicillin in the next order; basic subunit>glycinin>ß-conglycinin with MIC of 50, 100 and 1000 µg/mL, respectively. The IC(50%) values of the basic subunit, glycinin and ß-conglycinin against Listeria\monocytogenes were 15, 16 and 695 µg/mL, against Bacillussubtilis were 17, 20, and 612 µg/mL, and against S. Enteritidis were 18, 21 and 526 µg/mL, respectively. Transmission electron microscopy images of L. monocytogenes and S. Enteritidis exhibited bigger sizes and separation of cell wall from cell membrane when treated with glycinin or basic subunit. Scanning electron microscopy of B. subtilis indicated signs of irregular wrinkled outer surface, fragmentation, adhesion and aggregation of damaged cells or cellular debris when treated with glycinin or the basic subunits but not with penicillin. All tested substances particularly the basic subunit showed increased concentration-dependent cell permeation assessed by crystal violet uptake. The antimicrobial action of glycinin and basic subunit was swifter than that of penicillin. The cell killing efficiency was in the following descending order; basic subunit>glycinin>penicillin>ß-conglycinin and the susceptibility of the bacteria to the antimicrobial agents was in the next order: L. monocytogenes>B. Subtilis>S. Enteritidis. Adding glycinin and the basic subunit to pasteurized milk inoculated with the three bacteria; L. monocytogenes, B. Subtilis and S. Enteritidis (ca. 5 log CFU/mL) could inhibit their propagation after 16-20 days storage at 4 °C by 2.42-2.98, 4.25-4.77 and 2.57-3.01 log and by 3.22-3.78, 5.65-6.27 and 3.35-3.72 log CFU/mL, respectively.

Enhancing Milk Preservation with Esterified Legume Proteins.

Three methylated legume proteins; soybean protein, broad bean protein and chickpea protein as well as their respective native proteins were applied at two different concentrations (0.1 and 1%) to either raw or pasteurized milk before preservation at 4 °C for 7-14 days. Supplementation of raw milk with esterified legume proteins could ameliorate its preservation quality at 4 °C for 5 days, based on the total bacterial count (TBC) or the titratable acidity levels. Supplementing pasteurized milk with esterified legume proteins (0.1%) has significantly improved its keeping quality as it significantly reduced the total bacterial count by 3.33 and 1.80 log when preserved at 4 °C for 7 and 14 days, respectively. Esterified legume proteins (0.1%) could maintain the level of bacterial load of the pasteurized milk at its initial level of pasteurization (zero time) after 14 days of preservation at 4 °C under closed conditions.