Banana Pseudo-Stem Increases the Water-Holding Capacity of Minced Pork Batter and the Oxidative Stability of Pork Patties

Banana pseudo-stem (BPS), which is rich in fibre and polyphenols, is a potential functional ingredient for the food industry. In this study, BPS was added at concentrations of 1.5, 3.0, and 4.5 g/kg to a minced pork batter to evaluate its performance as a filler and to pork burger patties to evaluate its performance as a natural antioxidant. The effects of BPS were compared with those of carrageenan and ascorbate, which are a conventional binder and antioxidant, respectively. The performance of BPS was similar to that of carrageenan in terms of the cooking yield and texture of the cooked batter. BPS reduced the brightness of fresh patties and appeared to reduce oxidative discolouration during the frozen storage of raw patties. Moreover, BPS reduced the levels of thiobarbituric acid reactive substances (TBARS) during the refrigerated and frozen storage of cooked patties. A greater decrease in TBARS formation was observed with 4.5 g BPS/kg compared with 0.5 g sodium ascorbate/kg during refrigerated storage. In contrast to ascorbate, BPS promoted the presence of lipid-derived volatile compounds induced by thermal breakdown in the headspace of cooked patties. Nonetheless, this effect was reduced as the amount of BPS in the patties increased. In cooked minced meat products, BPS could increase cooking yields and lipid oxidative stability during storage and might result in a more intense flavour.

Comparison of oxidation status and antioxidant capacity of meat from surgically castrated and immunocastrated pigs, entire males and sows

The aim of the present study was to evaluate the influence of castration (surgical and immunological) and sex on lipid hydrolysis, oxidation and antioxidant capacity in selected muscles/cuts of pigs. Nine muscles/cuts from four groups of pigs (surgically castrated, entire males, immunocastrated and sow) were analysed. Free fatty acids (FFA) were analysed using standard methods according to CSN EN ISO 660. Thiobarbituric reactive substances (TBARS) were determined as malondialdehyde (MDA) equivalents and antioxidant capacity was evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) method . The highest content of FFA was observed in sows, detected to be significantly (P < 0.001) higher than in entire males. The highest content of TBARS was found in entire males; the content was significantly (P < 0.05) higher than in sows. Generally, the highest values of DPPH inhibition were detected in samples of surgically castrated pigs whereas the lowest values were observed in samples of entire males. Antioxidant capacity in musculus longissimus dorsi and backfat of surgically castrated pigs was significantly (P < 0.05) higher than in other evaluated groups of pigs. The study confirmed the differences in FFA and TBARS formation between analysed groups of pigs, probably due to differences in the fatty acid composition. The results of our study indicate that methods of castration have an effect on the antioxidant capacity of pork. These findings are of value to the meat industry.

Effect of Heating Methods on Quality Attributes of Culled Saanen Crossbred Goat Meat

The effect of boiling, grilling, and microwaving until reaching temperature of 85 °C on culled Saanen goat meat was evaluated and compared to raw samples. Biceps femoris muscle was used to evaluate the effect of these heating methods on proximate composition, collagen, cook loss, color, and texture profile analysis. Supraspinatus muscle was used to determine the effect of these heating methods on changes in peroxide value (PV) and thiobarbituric acid reactive substances (TBARS) of meat during 5 days of chilled storage. Boiled and grilled samples showed lower moisture (63.04 and 63.89 %, respectively) and higher protein (29.20 and 29.59 %, respectively) and fat (5.98 and 4.01 %, respectively) than those of the microwaved sample (68.03 % moisture, 26.72 % protein, and 2.95 % fat) (P < 0.05). Higher total collagen in the grilled sample (14.35 mg/g) and higher soluble collagen percentage (6.57 %) in the microwaved sample were obtained (P < 0.05). Boiled and grilled samples revealed higher cook loss (39.70 and 41.28 %, respectively) compared to microwaved samples (28.82 %) (P < 0.05). Grilled samples exhibited higher hardness (3,730.21 g), gumminess (2,397.76), and chewiness (1,774.71) than those of other heated samples (P < 0.05). Higher lightness (L* = 54.90), lower redness (a* = 4.11) and yellowness (b* = 13.96) in boiled sample were found (P < 0.05). Grilled samples exhibited sharper PV formation while boiled samples revealed sharper TBARS formation during storage (P < 0.05). In summary, variation in remaining moisture, soluble collagen, parallel with types of heating medium led to complexity in the results obtained in total solid, cook loss, color, and texture profile analysis (TPA). Boiled samples were prone to yield higher TBARS formation.

Counteracting effects on free radicals and histological alterations induced by a fraction with casearins

ABSTRACTCasearia sylvestris Swartz is a medicinal plant widely distributed in Brazil. It has anti-inflammatory, antiulcer and antitumor activities and is popularly used to treat snakebites, wounds, diarrhea, flu and chest colds. Its leaves are rich in oxygenated tricyclic cis-clerodane diterpenes, particulary casearins. Herein, we evaluated the antioxidant activities of a fraction with casearins (FC) isolated from C. sylvestrisand histological changes on the central nervous system and livers of Mus musculus mice. Firstly, in vitro studies (0.9, 1.8, 3.6, 5.4 and 7.2 μg/mL) revealed EC50 values of 3.7, 6.4 and 0.16 µg/mL for nitrite, hydroxyl radical and TBARS levels, respectively. Secondly, FC (2.5, 5, 10 and 25 mg/kg/day) was intraperitoneally administered to Swiss mice for 7 consecutive days. Nitrite levels in the hippocampus (26.2, 27.3, 30.2 and 26.6 µM) and striatum (26.3, 25.4, 34.3 and 27.5 µM) increased in all treated animals (P < 0.05). Lower doses dropped reduced glutathione, catalase and TBARS levels in the hippocampus and striatum. With the exception of this reduction in TBARS formation, FC displayed only in vitro antioxidant activity. Animals exhibited histological alterations suggestive of neurotoxicity and hepatotoxicity, indicating the need for precaution regarding the consumption of medicinal formulations based on Casearia sylvestris.

Lipid peroxidation and biochemical parameters in maternal pre-delivery and post-delivery plasma

Lipid peroxidation (LPX) can play an important role in development of functional and pathological changes of maternal tissues in the course of pregnancy and delivery. LPX products were measured as thiobarbituric acid reacting substances (TBARS), using malondialdehyde as the standard solution. Actual TBARS determined in maternal post-delivery plasma (2.71 ± 0.602 nmol/mL) were not statistically different from those determined in pre-delivery plasma (3.45 ± 0.530 nmol/mL). TBARS production was measured in vitro in the both incubated plasma (30 min, 37°C) with and without the added LPX activator (125 μM L-ascorbate plus 5 μM FeSO4). A difference in the TBARS formation was found only in the post-delivery plasma, as a result of approximately twice higher (marginally significant) TBARS formation in the incubated plasma without the added LPX activator comparing with the actual TBARS levels in this plasma. These results suggest that changes in maternal tissues in the process of labour could create suitable conditions for activation of LPX in maternal plasma. On the other hand, all other analysed biochemical parameters (iron, total iron-binding capacity, uric acid, proteins, magnesium, calcium, phosphate, glucose, potassium, sodium, chlorides, alanine aminotransferase, aspartate aminotransferase, γ-glutamyltransferase, creatine kinase, lactate dehydrogenase, α-hydroxybutyrate dehydrogenase, α-amylase, alkaline phosphatase, acid phosphatase in the post-delivery plasma were not different from those analysed in the pre-delivery plasma.

Hepatoprotective role of captopril on paraquat induced hepatotoxicity

Paraquat (PQ) is a highly toxic herbicide that is used in most of the countries without restriction. The cytotoxic effect of PQ is mediated by radicals, which are the products of PQ reduction in cells. The anti-oxidative action of captopril, an angiotensin-converting enzyme inhibitor, appears to be through its ability to scavenge reactive oxygen species. In this study, the heptoprotective effect of captopril against PQ-induced hepatotoxicity was evaluated using primary cultured rat hepatocytes. Hepatocytes were isolated from male Wistar rats using a two-step collagenase perfusion, following incubation in the presence of captopril at 0.1, 0.2, 0.4 and 0.8 mM with or without PQ (5 mM). Hepatoprotective effects of captopril were studied indicating glutathione level intensity, thiobarbituric acid reactive substances (TBARs) formation, lactate dehydrogenase (LDH) leakage and cell viability every 70 min for 210 min. Captopril at 0.2 mM concentration maintained the LDH leakage, glutathione level and cell viability in the presence of 5 mM PQ. In spite of a significant elevation in TBARs formation in the PQ group, captopril did not show any significant protection. In conclusion, our data reveals that incubation of freshly isolated rat hepa-tocytes with captopril (0.2 mM) significantly protected the hepatocytes against the cytotoxicity of PQ ( P < 0.05). Human & Experimental Toxicology (2007) 26, 789— 794

Combined Effect of Modified Atmosphere Packaging and Addition of Lycopene Rich Tomato Pulp, Oregano and Ascorbic Acid and Their Mixtures on the Stability of Beef Patties

Beef patties were treated with ascorbic acid, oregano extract, lycopene rich tomato pulp (LRTP) and their mixtures, packaged in modified atmosphere and stored at 2°C. Lipid oxidation (TBARS formation), metmyoglobin formation, psychrotrophic bacterial counts and sensory odour and discolouration were analyzed throughout 20 days of storage. TBA values of beef patties containing oregano were the lowest ( p < 0.05); those containing ascorbic acid and LRTP alone were also significantly lower ( p < 0.05) than the control. The formation of surface metmyoglobin was significantly delayed ( p < 0.05) by the addition of oregano alone and its mixtures with ascorbic acid and/or LRTP. Psychrotrophic bacterial counts were significantly lower ( p < 0.05) in patties treated with 500 ppm oregano. Sensory colour and odour characteristics of beef patties were in agreement with the results of lipid and pigment oxidation. The antioxidant ability of oregano was dependent on the concentration; the presence of 500 ppm extended the shelf life of beef patties by about 8 days. LRTP alone exerted a limited antioxidant effect, while its combination with oregano resulted in a reduction of the antioxidative effect of the latter.

Role of Component Herbs in Antioxidant Activity of Shengmai San — A Traditional Chinese Medicine Formula Preventing Cerebral Oxidative Damage in Rat

Traditional Chinese medicine (TCM) is an attractive model for studying antioxidant-based composite therapy. We previously reported that Shengmai San (SMS), a TCM formulation for treating cardiac disorders, inhibited cerebral oxidative damage in rats when evaluated by both glutathione peroxidase (GPX) activity loss and thiobarbituric acid reactive substance (TBARS) formation after forebrain ischemia-reperfusion. In the present study, we further examined the preventive effect of SMS and related decoctions composed of three component herbs (Panax ginseng, Ophiopogon japonicus and Schisandra chinensis) against oxidative brain injury to rationalize the complex formulation of SMS. Schisandra chinensis itself and decoctions containing it all inhibited TBARS formation in vivo. In contrast, Ophiopogon japonicus itself and formulations containing it had little effect on TBARS formation. GPX activity loss in vivo, on the other hand, was completely prevented only by SMS and Ophiopogon japonicus itself. A comparison of the in vitro antioxidant potential of SMS and related decoctions and in vivo effectiveness in preventing cerebral oxidative damage revealed that all the in vitro antioxidant indices examined here essentially correlated well with inhibition of TBARS formation in vivo. DPPH quenching and crocin bleaching activities showed particularly good correlation, and then, superoxide scavenging activity followed. However, none of them correlated with the inhibition of GPX activity loss in vivo. The role of each component herb is also discussed for the SMS effect.

Simultaneous production of carbon monoxide and thiobarbituric acid reactive substances in rat tissue preparations by an iron-ascorbate system

Most of the carbon monoxide (CO) produced by mammals is a product of the heme oxygenase (HO) reaction, the rate-limiting step in the heme degradation pathway leading to the generation of bilirubin in man. However, some CO is derived from other sources. We studied the association of CO production with lipid peroxidation in tissue preparations from adult male Wistar rats. Supernatants, from 20% tissue homogenates in potassium phosphate buffer, centrifuged for 1 min at 13 000 × g, were incubated for 30 min at 37°C in septum-sealed vials in the dark with ascorbate (100 µM) and Fe(II) (6 µM) and (or) Fe(III) (60 µM). Butylated hydroxytoluene (BHT, 100 µM) was added for the blank reaction. CO produced into the headspace was quantitated by gas chromatography. Thiobarbituric acid reactive substances (TBARS), conjugated dienes (CD), and lipid hydroperoxides (LOOH) in the reaction medium were quantitated by spectrophotometry. Of the tissues studied, CO and TBARS formation was greatest for brain, followed by kidney, lung, spleen, and blood, but no CO or TBARS formation was detected for testes, intestine, liver, and heart. Cell fractionation studies indicated that these differences might be due to the presence of endogenous soluble antioxidants in the latter tissues. Furthermore, these studies demonstrated that CO was exclusively generated by subcellular fractions that contained membranes. The magnitude of the rate of product formation in brain supernatants depended on the concentration of Fe(II) and (or) Fe(III). The formation of CO, TBARS, CD, and LOOH increased linearly with time for up to 30 min, but the rates of product formation were different. Product formation was completely inhibited by BHT (100 µM), biliverdin (50 µM), bilirubin (50 µM), citrate (100 µM), and the Fe(II) chelators, desferrioxamine mesylate (100 µM) and diethylenetriaminepentaacetate, but not by 10 µM of the HO inhibitor, zinc deuteroporphyrin bis glycol. We conclude that CO generation is associated with the process of in vitro lipid peroxidation in tissues with limited antioxidant reserves.Key words: brain, carbon monoxide, conjugated dienes, lipid peroxidation, thiobarbituric acid reactive substances (TBARS).