Effect of carboxy-hemoglobin on color stability of cooked pork sausage

To investigate the effect of carboxy-hemoglobin (CO-Hb) on the color of cooked pork sausage (CPS), 6 treatments with 5 levels of CO-Hb (0, 0.2, 0.4, 0.6, and 0.8%) and 0.015% NaNO₂ were manufactured. Increased CO-Hb decreased a* values, but increased L* and b* values significantly (p<0.05). Color of the 0.4% CO-Hb samples had no significant change (p>0.05) during the 29-day storage. Both CO-Hb and carboxy-myoglobin (CO-Mb) were found in the pigments extracted from the 0.4% CO-Hb non-cooked sausages. Therefore, CO-Hb showed a potential color agent in the manufacture of sausages.     

Effect of Eryngium caeruleum essential oil on microbial and sensory quality of minced fish and fate of Listeria monocytogenes during the storage at 4°C

The present study investigated in vitro antimicrobial activity of Eryngium caeruleum essential oil (EEO) against five foodborne pathogenic bacteria based on microdilution and disk diffusion methods. Moreover, its effects on specific spoilage microorganisms, inoculated Listeria monocytogenes, and its sensory changes in minced fish were evaluated during 12 days of storage at refrigeration temperature. The results showed that Staphylococcus aureus and Escherichia coli were the most sensitive and the most resistant bacteria with a minimum inhibitory concentration of 0.125 and 1 mg/ml, as well as inhibition zones of 15.66 and 11.66 mm, respectively. Regarding the antimicrobial effect of EEO on the microbial profile and inoculated L. monocytogenes, treating with 0.4% EEO caused a significant decrease in the studied microorganisms when compared to the control group (p < 0.05). In addition, considering the sensory evaluation, the best scores were observed for the samples treated with 0.2% and 0.4% EEO. However, none of the groups obtained acceptable scores until the final day of storage except for the color attribute. In general, sensory evaluation and its correlation with microbial counting indicated that the treatment with 0.4% EEO was able to preserve the microbial quality of the minced fish at refrigeration temperature without any undesirable sensory effects.     

Improving the textural properties of Egyptian kariesh cheese by addition of hydrocolloids

In this study, the effect of addition of hydrocolloids (commercial pectin, citrus pectin or carboxymethylcellulose) to Egyptian Kariesh cheese at 0.2, 0.4 and 0.6% (w/w) on chemical composition, yield, rheological and sensory characteristics was investigated. The results revealed that the addition of hydrocolloids increased moisture content and yield values of Kariesh cheeses compared with control. Protein, salt and ash content decreased with increasing hydrocolloids levels. Rheological characteristics (hardness, adhesiveness, springiness, cohesiveness, gumminess, chewiness, resilience) were significantly lower in cheeses made with hydrocolloids. Kariesh cheese made with 0.4% w/w commercial pectin and 0.6% w/w carboxymethylcellulose recorded the highest scores for sensory attributes.     

On the thermodynamic compatibility of Vicia faba protein with agar-agar in aqueous media

Based on phenomenological studies the thermodynamic compatibility is described Ly a phase diagram. It shows the concentration conditions for mixtures of Vicia faba protein and agar-agar in aqueous media leading to single-phase systems in solution or gel. Complete compatibility was found for agar-agar concentrations > 1.5% and Vicia faba protein concentrations ≤ 1 %. The same effect was observed for Vicia faba protein concentrations ≥ 1% and agar-agar concentrations ≤ 0.4%.     

Contamination of freshly harvested Bambara groundnut (Vigna subterranea) seed from Mpumalanga,South Africa,with mycotoxigenic fungi

Freshly harvested Bambara groundnut (BGN) is occasionally consumed raw and can potentially become infected with mycotoxingenic field fungi. In this study, BGN samples were obtained from 12 farms in three districts of Mpumalanga in South Africa. Eight pooled samples were screened for multi-mycotoxin contamination using Ultra Performance Liquid-Chromatography tandem mass spectrometry (UPLC-MS/MS). To identify mycoflora, 12 samples were screened using conventional and molecular methods. Selected potential mycotoxin producing isolates were screened for mycotoxins using UPLC-MS/MS. No mycotoxins were detected on the freshly harvested BGN samples, but they were infected with various mycotoxin producing fungal species namely Aspergillus flavus (50%), Penicillium citrinum (25%), Penicillium oxalicum (17%), Penicillium citreoviridin (0.8%), and Fusarium verticillioides (0.8%). Following screening of selected fungal cultures, aflatoxin B₁ (0.4, 0.45 and 0.4 ppm) and fumonisin B₁ (0.7 ppm) were detected from A. flavus and F. verticillioides, respectively. Identification of mycotoxigenic fungi on freshly harvested BGN presents a potential health risk.     

Effect of Sodium Acid Pyrophosphate in Combination with Sodium Nitrite or Sodium Nitrite/Potassium Sorbate on Clostridium botulinum Growth and Toxin Production in Beef/Pork Frankfurter Emulsions

Combinations of sodium acid pyrophosphate (SAPP) with added sodium nitrite and/or potassium sorbate were tested at various pH levels to determine effectiveness in delaying Clostridium botulinum growth and toxin production in frankfurter emulsions. Formulations containing sodium nitrite (40 ppm), potassium sorbate (0.26%) and SAPP (0.4%) resulted in a greater delay of toxin production (12–18 days) than other combinations (6–12 days) having similar pH values. Treatments containing 0.4% SAPP appeared to be more inhibitory than their counterparts without SAPP, displaying less numbers of toxic samples during the 53-day storage period at 27°C. Aerobic mesophilic colony counts and residual nitrite data showed little difference among treatments.     

Effect of Drying and Roasting on the Quality Attributes of Fufu Powder

Abstract

The effect of drying and roasting on the physicochemical and sensory qualities of fufu powder were investigated. The four samples of fufu: cooked dried fufu, cooked roasted fufu, dried fufu slurry and roasted fufu slurry, respectively, were subjected to physicochemical and sensory analysis. The water binding index, water solubility index, and water absorption index, varies between 3.44 and 0.17 (g/g sample), 0.07 and 0.01 (g/g), and 4.73 and 0.83 (g/g) respectively, while the starch damage and amylose content varies between 50.8% and 0.4%, 10% and 13% respectively, with roasted fufu slurries recording the highest values. The proximate composition of dried and roasted fufu samples showed the values of fat (0.6%–0.4%), protein content (0.2%–0.1%), ash content (37.8%–1.0%), moisture content (8.2%–10.2%), crude fibre (1.25%–8.5%) and carbohydrate content (43.0%–84.65%) respectively. Generally, there were no appreciable differences in the proximate composition of dried fufu samples. The pasting temperature of fufu samples varies from 78 to 95°C with roasted fufu slurries recording the highest values. The peak viscosity of dried fufu samples ranges between (80 and 900BU) and viscosity at 50°C ranges between (260 and 460BU). There are no significant differences (P > 0.01) for the sensory qualities in term of color, taste, and overall acceptability except for odor and texture at (P < 0.01).     

Shelf life of Merino lamb meat retail packaged under atmospheres of various compositions

The effect of four different gas mixtures on several characteristics of Merino fresh lamb meat quality was studied. Merino lamb meat was packed under four different atmospheres (Batch 1: Ambient air; Batch 2: 70% O₂ + 30% CO₂; Batch 3: 80% O₂ + 20% CO₂ and Batch 4: 30% CO₂ + 69.6% Ar + 0.4% CO) and stored in darkness and under refrigeration (3 ± 1 °C) for 12 days. pH values and weight losses of lamb meat showed no significant changes during 12 days storage (P > 0.05) and were not affected by the different used atmospheres (P > 0.05). Lightness (L*) was not significantly affected by gas atmospheres until day 12 of storage, lamb meat packed in contact with air (Batch 1) showing the lowest lightness (P < 0.001). Samples in contact with ambient air, presented the lowest a*‐values during most of the storage period (P < 0.001). Batch 4 (30% CO₂ + 69.6% Ar + 0.4% CO) showed the highest a*‐values after 7 days storage. Batches 2, 3 and 4 presented a lower microbial count of total aerobic bacteria and Enterobacteriaceae than batch 1 (P < 0.05), whereas for lactic acid bacteria counts there were not significant differences (P > 0.05).     

Comparative study of trans fatty acid content in 2005 and 2008 processed foods from Korean market

Trans fatty acids (t-FA) contents were analyzed in 26 food items that were collected from Korean grocery stores in 2005 and 2008. Lipid was extracted through Soxhlet and Mojonnier methods. Fatty acid profile, including t-FA and positional fatty acid composition was analyzed by gas chromatography. The comparative study of fatty acids composition including t-FA was employed in 2005 and 2008. Among the analyzed food items, most of the food items showed higher lipid content in 2005 than in 2008. Some food items such as biscuits (0.4–7.2 g/100 g of food), fried snacks (0.1–3.6 g/100 g of food), and cookies (0.4–2.4 g/100 g of food) contained relatively higher level of t-FA than other food groups (cracker, processed chocolate, and ice cream) in 2005. Comparing t-FA content in 2005, it was considerably decreased up to 91.5% in 2008 whereas saturated fatty acids (SFA) were increased up to 43.3% in the analyzed food items.     

Immunomodulatory and antioxidative potential of herb (Pueraria tuberosa) in mice using milk as the carrier

Eighteen healthy male mice were divided into three equal groups and given specific diets for a period of 28 days: Group M were fed a normal synthetic diet (NSD) and milk; Group P were fed NSD and Pueraria tuberosa (PT) extract (0.4%), while the diet of group PM was NSD supplemented with PT extract (0.4%) and milk. The phagocytic activity and immunoglobulin A (in intestines) and immunoglobulin G (serum) levels increased significantly in comparison with group M in PT supplemented groups after a period of 28 days. Group P and Group PM showed significantly higher reduced glutathione level and significantly lowered thiobarbituric acid reactive substances levels in liver and red blood cells as compared to control.     

Myofibrillar Protein Solubility of Model Beef Batters as Affected by Low Levels of Calcium, Magnesium and Zinc Chloride

Preblended composites of semimembranosus and adductor muscles were stored 12h at 4°C with 2.0% NaCl, 0 or 0.05% CaCl₂, MgCl₂, or ZnCl₂ and 0 or 0.4% sodium tripolyphosphate (STPP). Model systems were formulated to contain 30% fat (high fat; HF) or 10% fat (low fat; LF). Divalent salts lowered extract pH and ZnCl₂ elicited the greatest reduction. At both fat levels, CaCl₂ increased and ZnCl₂ decreased protein solubility, compared to the control (p<0.05). Myosin was not detected in ZnCl₂-treated HF and LF batters without STPP and in the presence of STPP, MgCl₂ and ZnCl₂ increased myosin concentration at both fat levels (p<0.05). Zinc chloride increased actin concentration in HF batters; whereas, MgCl₂ decreased soluble actin in LF batters (p<0.05). Magnesium chloride (0.05%) increased soluble proteins in LF batters containing 0.4% STPP by increasing myosin extractability.     

The impacts of water and ethanolic extracts of propolis on vacuum packaged sardine fillets inoculated with Morganella psychrotolerans during chilly storage

The impacts of water and ethanolic extracts of propolis at a dose of 0.4 or 0.8% on vacuum packaged sardine fillets inoculated with Morganella psychrotolerans DSM 17886 during storage at 3 ± 1°C for 15 days were investigated. All fish groups were inoculated with M. psychrotolerans (10⁸ cfu/ml) at a rate of 1%. Sensory, colorimetric, chemical analysis (total volatile basic nitrogen, thiobarbituric acid, peroxide values, and free fatty acids), pH value, and microbiological analysis (viable mesophilic and psychrophilic bacteria, coliform, and lactic acid bacteria count) were carried out. An enhance in L* values was found in the group treated with 0.8% ethanolic extracts of propolis on the seventh day of the storage. Application of propolis extract on fish fillets significantly inhibited bacterial growth during storage and extended shelf life of sardine for 4 and 6 days by the use of water extract and for 8 days by the use of ethanolic extract at doses of 0.4 and 0.8%, respectively. The result of the study revealed that application of propolis extracts, mainly ethanolic propolis extracts on sardine fillets resulted in lower lipid oxidation and bacterial growth, therefore, could be natural food additive for preservation of fish fillets.     

Amino Acid Profile of Insoluble Collagen Isolated from Fresh Water Prawn, Macrobrachium rosenbergii

Insoluble collagen was isolated from the abdominal tissue of fresh water prawn, Macrobrachium rosenbergii. The yield was 0.4–0.6%. The amino acid profile of this insoluble collagen was elucidated with 81.6 hydroxyproline residues per 1000 collagen amino acid residues or 2 mg hydroxyproline per 100 mg insoluble collagen. A comparison was made between the amino acid profile of insoluble collagen from M. rosenbergii and that of P. setiferus.     

Degradation of condensed tannins by rumen microbes exposed to quebracho tannins (QT) in rumen simulation technique (RUSITEC) and effects of QT on fermentative processes in the RUSITEC

In an earlier study it was observed that the rumen microbes from cattle which had never consumed tannin-containing diets do not have enzymes for degrading condensed tannins. In this study, rumen microbes were exposed to small amounts of quebracho tannins for 8 days using a rumen simulation technique (RUSITEC). The levels maintained in the RUSITEC were 0.1, 0.2 and 0.4 mg of the spray-dried quebracho powder (SDQT) per ml of the medium. After 8 days of tannin exposure, the liquor containing ‘exposed/adapted’ microbes from RUSITEC was incubated for 40 h without and with purified tannins of quebracho and Dichostachys cinerea leaves in in vitro gas method. There was no degradation of condensed tannins. The enzymes for degradation of condensed tannins were not induced in rumen microbes by exposure to different concentrations of tannins for 8 days in the RUSITEC. In the RUSITEC, SDQT significantly reduced the number of total protozoa, entodiniomorphs and holotrichs; effect was higher on holotrichs. There was no significant change in the levels of short chain fatty acid but the molar proportion of propionate was significantly higher and of butyrate significantly lower at 0.4 mg SDQT ml^?1. Significantly lower levels of ammonia in the medium was also observed on injection of tannins. Microbial mass production, calculated using ¹⁵N incorporation, was similar at 0.1 and 0.2 mg SDQT ml^?1 but significantly lower (13%) at 0.4 mg SDQT ml^?1. The dry matter digestibility of the feed (80% hay and 20% barley) was not significantly affected by SDQT.     

Resistance of Lactobacillus casei KCTC 3260 to Reactive Oxygen Species (ROS): Role for a Metal Ion Chelating Effect

The antioxidative capacity of 4 Lactobacillus strains, isolated from a milk product, was evaluated by measuring total antioxidative ability (TAA) and resistance to reactive oxygen species (ROS). Both intact cells and intracellular cell‐free extracts of Lactobacillus casei KCTC 3260 demonstrated the highest antioxidative activity and inhibited lipid peroxidation by 46.2% and 72.9%, respectively. To evaluate the resistance of 4 Lactobacillus strains to ROS, we tested the survival under conditions of 1 mM hydrogen peroxide, 0.4 mM hydroxyl radicals, and 10 mM paraquat‐induced superoxide anions. L. casei KCTC 3260 was viable even after 8 h in the presence of 1 mM hydrogen peroxide and after 7 h in 0.4 mM hydroxyl radicals. Moreover, this strain was not influenced by superoxide anions, indicating that it has resistance to superoxide anions. To define the antioxidative mechanism, superoxide dismutase (SOD) and metal ion chelating activity were determined. All tested strains did not possess detectable SOD activity except Lactobacillus rhamnosus GG, but L. casei KCTC 3260 had the higher level of chelating activity for both Fe²⁺ and Cu²⁺ ions at 10.6 ppm and 21.8 ppm, respectively. These results suggested that the antioxidative capacity of L. casei KCTC 3260 may be caused by chelating metal ions instead of SOD activation.     

Quality Characteristics of Restructured Turkey Meat with Variable Alginate/Calcium-Lactate Ratios

Restructured ground turkey and turkey breast meat patties, formulated with combinations of 0–1.0% sodium alginate, 0–0.1875% calcium carbonate and 0–0.6% lactate, were compared to a no additive control. The ratio of sodium alginate to calcium carbonate was held constant at 5.3 to 1. Optimal sensory and instrumental raw and cooked product bind was achieved with combinations of 0.4–1.0% sodium alginate, 0.0750–0.1875% calcium carbonate and 0.6% lactate. All restructured products with the algin/calcium binder had higher (p<0.05) cook yields than the no additive control. Sensory aroma, flavor and juiciness of cooked products were not different (p>0.05) between treatments.     

Effect of the modified high methoxyl pectin on the stability of the fermented milk beverage

Stability of milk drinks could be improved by adding high methoxyl pectin. In this work, effect of the modified high methoxyl pectin (MHMP) on the fermented milk beverage (FMB) was investigated by the characteristics of adsorption, viscosity, rheological properties, particle size, zeta-potential (ζ-potential), microstructure, and phase behavior. The low concentration of MHMP (<0.2%, w/v) and final pH (<4.0) might easily cause the instability among the particles inducing from the bridging flocculation. The FMB system obviously had a good stability as the adding of 0.4% MHMP. Meanwhile, the particle size had a slight downward trend with decreasing the value of pH. The increase of MHMP concentration could increase the properties of viscosity and ζ-potential. However, the ζ-potential of the system had a decreasing trend by reducing the pH of the FMB with the same concentration of MHMP. The microstructure of the FMB was thick and dense compared with the sample without MHMP. As the concentration of MHMP was above 0.4%, the FMB system presented the uniform dispersion and only slight stratification water occurred for the phase behavior. Besides, it was also indicated that most part of MHMP was not adsorbed onto the casein micelles but was involved in a network with MHMP/casein complexes in the FMB.     

Physicochemical,rheological and sensory properties of Egyptian Kariesh cheese containing wheat bran

The physicochemical, rheological and sensory properties during the storage of Kariesh cheeses made with 0.1, 0.2, 0.3, 0.4 or 0.5 g wheat bran/100 g milk were evaluated at 0, 7 and 15 days. The cheeses with 0.5 g wheat bran/100 g milk had a significantly (P < 0.01) higher yield and moisture content, and lower pH and protein content than the control. No significant differences (P > 0.01) in salt and ash contents were observed among the cheeses studied. Texture profile analysis showed that the rheological characteristics decreased significantly in cheeses made with wheat bran. These results suggested that wheat bran (up to 0.4%) can be used to produce a fibre fortified Kariesh cheese.     

The fatty acid composition of Hibiscus sabdariffa seed oil

Analysis of Hibiscus sabdariffa seed oil from different seed collections (or cultivars), representing different growing areas, showed differences in the fatty acid pattern, especially with respect to linoleic (30.1-37.45%) and epoxyoleic (trace to 5.3%). The results showed different values from those previously reported for the cyclopropenoid fatty acid, found to be malvalic acid (0.4-2.0%), responsible for the positive Halphen response of the oil. It is now also established that the oil contains dihydrosterculic acid (1.0-1.6%) which has been reported previously in other species of the genus Hibiscus. The results of the rest of fatty acids showed ranges for myristic 0.2-0.5%, palmitic 17.4-22.6%, stearic 3.9-5.2% and oleic acid 34.6-39.8%.     

Short chain xylooligosaccharides: a potential prebiotic used to improve batter fermentation and its effect on the quality attributes of idli,a cereal–legume‐based Indian traditional food

Xylooligosaccharides (XOS), a potential prebiotic exhibits important technological characteristics and interesting nutritional properties. The major fraction in XOS produced enzymatically from corncob was characterised as β‐d ‐xylopyranosyl‐(1,4)‐d ‐xylanopyranose (xylobiose) using ¹³C and 2D‐HSQC NMR. The use of this XOS as a prebiotic in idli, a cereal/legume‐based fermented cake, and its effect on texture, fermentation and sensory characteristics was investigated. Idli batter was fermented with different concentrations of XOS (0, 0.2, 0.4 and 0.6% w/v) for 4–18 h conventionally. The addition of XOS markedly increased lactic acid bacteria number (9.88 ± 0.08 log cfu g^?1) which resulted in rapid reduction in pH (4.61 ± 0.03) and specific gravity after 6 h of fermentation when compared to conventional batter fermentation for 18 h without XOS (9.46 ± 0.06 log cfu g^?1). Instrumental (colour and texture) and sensory evaluation indicated that the optimum conditions were 0.4% XOS and 6 h fermentation. Idlis with XOS had higher moisture content and a softer texture. Addition of XOS benefits both fermentation and idli quality.