Effect of different treatments on the microstructure and functional and pasting properties of pigeon pea (Cajanus cajan L.), dolichos bean (Dolichos lablab L.) and jack bean (Canavalia ensiformis) flours from the north‐east Argentina

The effect of germination (G; 5 days), soaking‐cooking (SC; 6 h–20 min, 6 h–40 min, 6 h–60 min) and microwave (M; 50%, 70%, 100%) treatments on pigeon pea (PP), dolichos bean (DB) and jack bean (JB) seeds was studied. Microstructure of seeds and functional (protein solubility, water‐holding capacity, oil‐holding capacity, emulsion stability) and pasting properties of flours were determined. Germination and microwave treatments modified the protein matrix of cotyledon cells preserving the shape of the starch granule, whereas the SC treatment (6 h–60 min) affected both. The soaking‐cooking is the most influential treatment on the functional properties of PP, DB and JB flours, as increased water absorption capacity (73–96%), decreased protein solubility (>80%) and the tendency to retrogradation of amylose (69–85%) also improved emulsion stability.     

Enhancement of phenolic compounds content and antioxidant activity of strawberry (Fragaria × ananassa) juice by block freeze concentration technology

The aim of this study was to evaluate the effects of freeze concentration of strawberry juice on content of total phenolic, anthocyanins content and antioxidant activity of the concentrated fluid and the ice obtained. An increase in the values of phenolic content was observed in the concentrate fraction for all the freeze concentration stages (five stages). The process efficiency presented a reduction when compared with the first stage, and however, the average efficiency remained around 65% in all the stages. The concentration of pelargonidin‐3‐O‐glycoside present in samples was increased in all stages. Furthermore, the antioxidant activity of the concentrated fluid of each stage, measured by DPPH and ABTS methods, was significantly higher in comparison with the juice feed. Also, antioxidant activity can be correlated with the content of pelargonidin‐3‐O‐glycoside presented in the strawberry juice. Freeze concentration can be considered a good alternative for improving the antioxidant activity of strawberry juice.     

Freeze‐drying concentration of Rangpur lime juice

The use of freeze‐drying for concentrating lime Rangpur juice was investigated. This procedure allowed obtaining concentrated Rangpur lime juices between 23 and 51.3 °Brix, without affecting their organoleptic and nutritional characteristics. The efficiency of the procedure was inversely related to the film thickness of the matrix to be lyophilised. The sublimation speed per unit area diminished with the reduction in the residual moisture content of the juice. The mathematical model that fitted to the concentration procedure allowed to predict the time required for concentrating Rangpur lime by freeze‐drying starting from samples of different thickness. When compared with other citric juices evaluated, the Rangpur lime juice was the most suitable for freeze‐drying concentration. The results could be used to devise optimal industrial freeze‐drying cycles for processing Rangpur lime juices at different concentrations.     

Supplementing fresh pasture with maize,lotus, sulla and pasture silages for dairy cows in summer

A trial was conducted to compare benefits obtained from feeding four types of silage. There were two silages that contained condensed tannins (CT)—lotus (Lotus corniculatus) and sulla (Hedysarum coronarium)—maize silage or traditional ryegrass pasture silage, all fed at 5 kg dry matter (DM) cow^?1 day^?1 with restricted pasture (RP). Cows on the RP (control) treatment and those fed the silage treatments were offered an allowance of 25 kg pasture DM cow^?1 day^?1, while the full pasture (FP) cows were offered 50 kg pasture DM cow^?1 day^?1. Silage supplementation increased both DM intake and milk yield compared with cows given RP only. Cows on the lotus silage supplement and the FP treatment had significantly higher milk production than the other silage supplemented cows (P < 0.001). For cows given lotus silage, the high milk yield was probably due to a combination of the higher nutritive value of the silage and possibly to the protein‐sparing effects of the lotus condensed tannins because the total DM intake of cows fed the lotus silage was the same as that of cows given the pasture and maize silages (P > 0.25). The high milk yield of the FP treatment was mainly a result of the cows having a higher intake of pasture than cows on all the other treatments. This study demonstrated the potential benefit of silage supplementation, particularly with lotus silage, for increased milksolids yield in summer when low pasture growth rates and quality may otherwise limit production. Copyright © 2006 Society of Chemical Industry     

Do as I say or as I do? Food handler's knowledge on good handling practices and evaluation of hygienic–sanitary conditions in hospital foodservices

The aim of the study was to evaluate the overall hygienic–sanitary conditions of university hospitals foodservices and assess food safety knowledge and self‐reported practices of food handlers. A self‐administered questionnaire based on sanitary standards for foodservices was given to 123 food handlers from three public hospitals. Microbiological analysis of food handling surfaces and food hygiene inspections were also performed. Food handlers' self‐reported knowledge and practices reached satisfactory levels (77.2% and 78.1%, respectively), and showed a significant positive intercorrelation (p < .05). Food hygiene inspections in the hospitals foodservices presented a 60.9% average of adequacy and microbiological analysis results showed that 66.7% of the evaluated surfaces presented significant contamination by mesophilic bacteria. The presence of coliforms at 45°C above the safety limit was identified in 47.9% of the surfaces. The results showed a need for motivating hospital food handlers to practice the safe handling knowledge that they have demonstrated in theory.     

Molecular and toxigenic characterization of Bacillus cereus and Bacillus thuringiensis strains isolated from commercial ground roasted coffee

Thirty samples of roasted ground coffee beans from 10 different commercial brands were analyzed to investigate the occurrence and levels of Bacillus cereus and Bacillus thuringiensis strains. Strains were evaluated for their genetic diversity by repetitive element sequence polymorphism PCR (Rep-PCR) and for their toxigenic profiles, i.e., the presence of hblA, hblC, hblD, nheA, nheB, nheC, cytK, ces, and entFM. Survival and multiplication of B. cereus sensu lato in the ready-to-drink coffee was determined to evaluate this beverage as a possible vehicle for B. cereus infection. B. cereus was detected in 17 (56.7%) of the 30 samples, and B. thuringiensis was detected in 8 (26.7%) of the 30 samples. Five samples did not produce any characteristic growth. The most common gene, entFM, was detected in 23 strains (92%). The NHE complex (nheA, nheB, and nheC genes) was found in 19 strains (76%). The HBL complex (hblA, hblC, and hblD) was found in 16 strains (64%). All strains were negative for ces. The cytK gene was found in 16 strains (64%). The computer-assisted cluster analysis of Rep-PCR profiles using a clustering criterion of 80% similarity revealed four main clusters. Cluster 1 was the predominant and comprised three B. thuringiensis strains with 100% similarity, cluster 2 comprised two B. cereus strains (100% similarity), cluster 3 comprised two B. thuringiensis strains (90% similarity), and cluster 4 comprised one B. thuringiensis strain and one B. cereus strain (85% similarity). The cluster analysis of fingerprints generated by Rep-PCR revealed a high genetic diversity among the B. cereus strains, suggesting that the contamination could have originated from different sources. In our experiments, when sugar was added and the beverage was kept in thermic bottles there was a significant increase in B. cereus sensu lato levels, which may increase the risk of food poisoning. These results highlight the need for additional studies on this subject to better evaluate coffee as a food poisoning vehicle.     

Genetic diversity, antimicrobial resistance and toxigenic profiles of Bacillus cereus isolated from food in Brazil over three decades

Bacillus cereus is an ever-present problem. It is widely distributed in several environments such as soil and plants and is commonly isolated from food and additives. In this study we analyzed 97 foodborne B. cereus sensu stricto strains isolated in Brazil in the 1980's, 1990's and 2000's in order to investigate the genetic diversity (assessed by Rep-PCR), antimicrobial resistance and toxigenic profiles (presence of hblA, hblC and hblD; nheA, nheB and nheC as well as cytK, ces and entFM genes) of such strains. The majority of the strains (79, 81.4%) were β-hemolytic. The NHE complex was found in 82 strains (84.5%) and HBL complex was found in 61 (62.9%) strains. All strains were negative to ces. The cytK-2 gene was found in 44 (45.4%) strains. The predominant toxigenic pattern was type I (32, 33%) which included strains positive for all toxin genes but ces. Computer assisted cluster analysis of Rep-PCR profiles showed a high genetic diversity. Seven major clusters comprising two or more strains were found and cluster 1 was predominant (ten strains, nine of them showing 100% similarity). This cluster included strains isolated in the 1980's and the 1990's. Cluster analysis of Rep-PCR profiles based on decade of isolation, source, hemolytic pattern, toxigenic and antibiotic resistance patterns revealed a similar clustering pattern as found in the analysis including all strains. The inability to observe a predominant band pattern when Rep-PCR cluster analysis was based on decade of isolation suggests that this diversity has been maintained over time. All strains were susceptible to gentamicin. We detected resistance to tetracycline (11 strains showing intermediate resistance and nine completely resistant strains), clindamycin (ten intermediate strains) and vancomycin (one strain). Clindamycin resistance showed statistical association with strains isolated in 2000's. The predominant resistance pattern was type A (72, 72.2%) which included strains susceptible to all drugs tested. Our results suggest that the majority of the strains present in several types of food in Brazil pose a potential risk to cause food poisoning due to the high prevalence of toxin genes found in these strains. However, additional studies involving cytotoxicity tests and affiliation of these strains to phylogenetic groups based on molecular data would be useful to better evaluate this potential and could provide a more accurate indication of the risk.     

Evaluation of the effect of probiotic cultures added to commercial yogurt over a known population of Listeria monocytogenes and Escherichia coli O157:H7

The effect of probiotic cultures over Listeria monocytogenes and Escherichia coli O157:H7 during yogurt storage was evaluated. Two different yogurt brands, one with additional probiotic cultures (Lactobacillus casei and L. acidophilus) were inoculated with known populations (106 UFC/g) of either L. monocytogenes or E. coli O157:H7 in three different times and stored for 32 days at 5 degrees C. Every four days the count of lactic bacteria, the added pathogens and pH was evaluated, according to the methodology described in the Bacteriological Analytical Manual. The pH and lactic bacteria population were constant during the testing period. Yogurt with additional probiotic cultures reduced the population of L. monocytogenes in 8 days, the population of E. coli O157:H7 in 16; yogurt with no additional probiotics took 20 days to reduce L. monocytogenes to non-detectable levels and even after 28 days of storage, E. coli O157:H7 was cultured. In this work, the beneficial effects of additional probiotic cultures in yogurt is confirmed again.     

Antioxidant intake among Brazilian adults - The Brazilian Osteoporosis Study (BRAZOS): a cross-sectional study

Background  

Antioxidant nutrient intake and the lesser formation of free radicals seem to contribute to chronic diseases. The aim of the present study was to evaluate the intake profile of the main dietary antioxidants in a representative sample of the adult Brazilian population and discuss the main consequences of a low intake of these micronutrients on overall health.