Evaluation of two natural extracts (Rosmarinus officinalis L. and Melissa officinalis L.) as antioxidants in cooked pork patties packed in MAP

Two natural extracts, from rosemary (Rosmarinus officinalis L.; Nutrox) and lemon balm (Melissa officinalis L.; Meliox) showing a potential antioxidant activity, have been evaluated and compared with a synthetic antioxidant (Butylated hydroxytoluene; BHT) and a control batch. Pork meat patties were made by addition of the mentioned compounds, cooked and packed in modified atmosphere and stored under illumination for 6 days. A descriptive sensory analysis was also conducted. The patties with natural extracts showed higher a*-values (P<0.001) than control and BHT samples. Cooked pork hardness was the lowest for Meliox batch after 0 and 3 days of storage in comparison with the rest of the batches. Nutrox batch showed the lowest TBARS values and hexanal content (P<0.05) throughout the storage period. The batches with natural antioxidants produced the highest concentrations of free thiol groups after 0 and 3 days. Differences in sensory attributes among batches were not detected by the judge panel.

Chitosan-glucose conjugates: influence of extent of Maillard reaction on antioxidant properties

Chitosan-glucose conjugates were prepared using Maillard reaction chemistry. Water-soluble and acid-soluble chitosan-glucose mixtures were heated at pH 4.9 and 6.0 at 98 °C. Mixtures at pH 6.0 containing acid-soluble chitosan gelled when heating was continued after reaching 98 °C and withstood gelation for only 30 min at pH 4.9. In contrast, mixtures containing water-soluble chitosan could be heated without gelation at pH 6.0 and 4.9. Examination of the extent of Maillard reaction and antioxidant properties showed that acid-soluble chitosan reacted for 30 min at pH 4.9 had the highest extent of reaction as judged by increased absorbance, the highest degree of modification to the amino group as evidenced by Fourier transform infrared and shifts of the endotherms by differential scanning calorimetry, and the highest antioxidant activity as indicated by ferric reducing power and oxygen radical absorbance capacity. There were significant correlations (p < 0.05) between indices of browning and antioxidant activity.

Antioxidant activity of hydrolysates and peptide fractions derived from porcine hemoglobin

Porcine hemoglobin hydrolysate (PHH) was prepared with 6 different proteases (flavourzyme, papain, A.S.1398, alcalase, pepsin and trypsin). There was no correlation between extent of hydrolysis and antioxidant activity (p > 0.05). The peptic hydrolysate prepared at 60 min possessed the strongest antioxidant potential (67.0 ± 1.84%) among different hydrolysates, which was fractionated into 4 major types by ultrafiltration membranes with different molecular weight cut-off (MWCO), PHH-I (Mw > 10 kDa), PHH-II (Mw = 5-10 kDa), PHH-III (Mw = 3-5 kDa) and PHH-IV (Mw < 3 kDa). PHH-IV possessed higher inhibitory effects of lipid peroxidation and scavenging effects on superoxide radical compared with larger MW fractions. Four fractions possessed the scavenging effects on 1, 1-diphenyl-2-picrylhy-drazyl (DPPH) and hydroxyl radicals in the order PHH-IV > PHH-I > PHH-III > PHH-II. MW of the 2 major peptide fractions from PHH-IV was located at 2476 Da (F1) and 1042 Da (F2), respectively. PHH-IV could be utilized to develop physiologically functional foods or therapy drugs.

The use of natural herbal extracts for improving the lipid stability and sensory characteristics of irradiated ground beef

Ground Longissimus dorsi of beef were treated with herbal extracts of marjoram, rosemary and sage at concentration of 0.04% (v/w), radiation (2 or 4.5 kGy) or their combination. Treated samples were stored at 5°C and analyzed periodically for thiobarbituric acid reactive substances (TBARS), sensory characteristics and psychrotrophic bacterial counts during storage for 41 and 48 days for samples treated at 2 and 4.5 kGy respectively. Results demonstrated a significant benefit of the addition of herbal extracts to the ground beef prior to irradiation. All three extracts significantly (P<0.05) lowered the TBARS values and off-odor scores and significantly (P<0.05) increased color and acceptability scores in all samples with marjoram being the most effective. The combination treatment with herbal extracts plus irradiation resulted in extension of the shelf life of samples treated with 2 kGy by one week and samples treated with 4.5 kGy by two weeks, over that treated with irradiation alone. In conclusion, the addition of herbal extracts can minimize lipid oxidation, improve color and decrease off-odor production in irradiated ground beef.

Antioxidant activity of bovine and porcine meat treated with extracts from edible lotus (Nelumbo nucifera) rhizome knot and leaf

Lotus (Nelumbo nucifera) is an extensively cultivated vegetable in eastern Asia, particularly in China. Both lotus rhizome knot (LRK) and lotus leaf (LL) are waste products of the lotus industry. Extracts from LRK and LL are proposed as antioxidants for meat. Porcine and bovine ground meat samples were subjected to three treatments: CONTROL (with no additives), LRK (lotus rhizomes knot extract 3% w/w), and LL (lotus leaf extract 3% w/w). Raw and cooked samples were stored at 4°C and the antioxidant activity was determined at 1, 3, 6 and 10 days. Antioxidant activity was significantly increased in all meat samples with the addition of both LRK and LL, but LRK was more effective against lipid oxidation. The results show the potential for using LRK and LL extracts in the meat industry to prolong shelf life.

Review of antimicrobial and antioxidative activities of chitosans in food

Interest in chitosan, a biodegradable, nontoxic, non-antigenic, and biocompatible biopolymer isolated from shellfish, arises from the fact that chitosans are reported to exhibit numerous health-related beneficial effects, including strong antimicrobial and antioxidative activities in foods. The extraordinary interest in the chemistry and application in agriculture, horticulture, environmental science, industry, microbiology, and medicine is attested by about 17,000 citations on this subject in the Scopus database. A special need exists to develop a better understanding of the role of chitosans in ameliorating foodborne illness. To contribute to this effort, this overview surveys and interprets our present knowledge of the chemistry and antimicrobial activities of chitosan in solution, as powders, and in edible films and coating against foodborne pathogens, spoilage bacteria, and pathogenic viruses and fungi in several food categories. These include produce, fruit juices, eggs and dairy, cereal, meat, and seafood products. Also covered are antimicrobial activities of chemically modified and nanochitosans, therapeutic properties, and possible mechanisms of the antimicrobial, antioxidative, and metal chelating effects. Further research is suggested in each of these categories. The widely scattered data on the multifaceted aspects of chitosan microbiology, summarized in the text and in 10 tables and 8 representative figures, suggest that low-molecular-weight chitosans at a pH below 6.0 presents optimal conditions for achieving desirable antimicrobial and antioxidative-preservative effects in liquid and solid foods. We are very hopeful that the described findings will be a valuable record and resource for further progress to improve microbial food safety and food quality.

Effect of variable sulfur supply on arsenic tolerance and antioxidant responses in Hydrilla verticillata (L.f.) Royle

In the present study, Hydrilla verticillata plants were exposed to arsenate (AsV; 50 microM) and arsenite (AsIII; 5 microM) under variable S supply: deficient (2 microM S, -S), normal (1 mM S, +S) and excess (2 mM S, +HS). Arsenic accumulation (microg g(-1) dw) in +HS plants was about 2-fold higher upon exposure to both AsV (30) and AsIII (50) than that observed in +S (12 & 24) and -S (14 & 26) plants. Despite lower As accumulation, -S plants experienced the maximum oxidative stress owing to an inadequate response of enzymatic and molecular antioxidants and significant decline in total thiols and the ratio of reduced glutathione (GSH) to oxidized glutathione (GSSG). By contrast +HS plants had significant increase in total thiols and an improved redox status, did not demonstrate any negative impact to antioxidants except catalase and hence experienced the least increase in oxidative stress parameters. In conclusion, an increase in S supply to plants may improve their accumulation capacity for As through enhanced tolerance caused by a positive effect on thiol metabolism and antioxidant status of the plants.

Consumer perceptions of beef healthiness: results from a qualitative study in four European countries

Background

Consumer perception of the healthiness of beef is an important determinant of beef consumption. However, little is known about how consumers perceive the healthiness of beef. The aim of this study is to shed light on the associations between beef and health.

Methods

Eight focus group discussions were conducted in four European countries (France, UK, Germany, Spain), each consisting of seven to nine participants. A content analysis was performed on the transcripts of these discussions.

Results

Although beef was generally perceived as healthful, focus group participants expected positive as well as negative effects of beef consumption on their health. Labelled, branded, fresh and lean beef were perceived as signalling healthful beef, in contrast with further processed and packaged beef. Consumers felt that their individual choices could make a difference with respect to the healthiness of beef consumed. Focus group participants were not in favour of improving beef healthiness during processing, but rather focussed on appropriate consumption behaviour and preparation methods.

Conclusions

The individual responsibility for health implies that consumers should be able to make correct judgements about how healthful their food is. However, the results of this study indicate that an accurate assessment of beef healthiness is not always straightforward. The presented results on consumer perceptions of beef healthiness provide insights into consumer decision making processes, which are important for the innovation and product differentiation in the European beef sector, as well as for public health policy decisions related to meat consumption in general and beef consumption in particular.

Advances in ingredient and processing systems for meat and meat products

Changes in consumer demand of meat products as well as increased global competition are causing an unprecedented spur in processing and ingredient system developments within the meat manufacturing sector. Consumers demand healthier meat products that are low in salt, fat, cholesterol, nitrites and calories in general and contain in addition health-promoting bioactive components such as for example carotenoids, unsaturated fatty acids, sterols, and fibers. On the other hand, consumers expect these novel meat products with altered formulations to taste, look and smell the same way as their traditionally formulated and processed counterparts. At the same time, competition is forcing the meat processing industry to use the increasingly expensive raw material "meat" more efficiently and produce products at lower costs. With these changes in mind, this article presents a review of novel ingredient systems and processing approaches that are emerging to create high quality, affordable meat products not only in batch mode but also in large-scale continuous processes. Fat replacers, fat profile modification and cholesterol reduction techniques, new texture modifiers and alternative antioxidant and antimicrobial systems are being discussed. Modern processing equipment to establish continuously operating product manufacturing lines and that allow new meat product structures to be created and novel ingredients to be effectively utilized including vacuum fillers, grinders and fine dispersers, and slicers is reviewed in the context of structure creation in meat products. Finally, trends in future developments of ingredient and processing systems for meat products are highlighted.

Hypoglycemic effects of Cecropia pachystachya in normal and alloxan-induced diabetic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Leaves of Cecropia pachystachya are described in the folk medicine as possessing antitusive, expectorant, antiasthmatic and hypoglycemic effects.

AIM OF THE STUDY

To investigate the hypoglycemic and antioxidant effects of methanolic extract from the leaves of Cecropia pachystachya. The total amount of phenolic and flavonoids compounds was determined and the qualitative composition of the extract was analyzed.

MATERIALS AND METHODS

The hypoglycemic effect of the extract was tested in normal, glucose loading and alloxan-induced diabetic rats. The antioxidant activity was assessed by DPPH free radical scavenging and reduction power assays. The total amount of phenolic and flavonoids compounds was determined by Folin-Denis and AlCl(3) reagent method, respectively. The qualitative composition of the extract was analyzed using a HPLC-DAD system.

RESULTS

The glucose tolerance test showed that in diabetic rats, the extract caused a significant hypoglycemic effect with a blood glucose reduction of 68% after 12h. The administration of the extract in alloxan-induced diabetic rats also produced a significant reduction in the blood glucose levels at all points being more pronounced at 90min (reduction of 60%). After 120min, no significant difference was observed between the blood levels of the rats treated with the extract and those treated with the standard drugs (metformin and glibenclamide). The extract also presented relevant antioxidant activity with IC50=3.1microg/ml (DPPH assay) and EC50=10.8microg/ml (reduction power). Results were compared with the reference antioxidants quercetin, rutin, and ascorbic acid. The content of flavonoids was 83mg/g plant and that of phenolics was 326mg/g plant. Chlorogenic acid and the C-glycosylated flavones, orientin and isoorientin, were identified in the extract.

CONCLUSIONS

In conclusion, the findings showed that the folk medicinal plant Cecropia pachystachya possesses hypoglycemic and antioxidant effects which confirmed the traditional use of the plant in the treatment of diabetes. Chlorogenic acid and the C-glycosylated flavonoids may explain these activities.

Efeito da irradiação em carne de coelho congelada

O crescimento nacional da produção de carne de coelhos necessita de maior conhecimento sobre características da carne, bem como o efeito de um processo que permita sua maior conservação. Os cortes congelados da carne de coelho: coxa, pernil e lombo, tratados com dois tipos de antibióticos, norfloxacina e ciprofloxacina, foram irradiados nas doses de 0, 3 e 6 kGy e determinados os teores de ferro heme e não heme dos cortes. As doses de irradiação empregadas foram influentes nos teores de ferro heme e não heme, sendo que a dose de 3 kGy foi a que apresentou os maiores valores, independente do tipo de antibiótico utilizado. Para o ferro heme o antibiótico norfloxacina apresentou os maiores valores e para o ferro não heme os maiores valores foram notados para o antibiótico ciprofloxacina.