Use of mild irradiation doses to control pathogenic bacteria on meat trimmings for production of patties aiming at provoking minimal changes in quality attributes

The objectives of the present work were to assess the use of moderate doses of gamma irradiation (2 to 5 kGy) and to reduce the risk of pathogen presence without altering the quality attributes of bovine trimmings and of patties made of irradiated trimmings. Microbiological indicators (coliforms, Pseudomonas spp and mesophilic aerobic counts), physicochemical indicators (pH, color and tiobarbituric acid) and sensory changes were evaluated during storage. 5 kGy irradiation doses slightly increased off flavors in patties. Two pathogenic markers (Listeria monocytogenes and Escherichia coli O157:H7) were inoculated at high or low loads to trimming samples which were subsequently irradiated and lethality curves were obtained. Provided that using irradiation doses ≤ 2.5 kGy are used, reductions of 2 log CFU/g of L. monocytogenes and 5 log CFU/g of E. coli O157:H7 are expected. It seems reasonable to suppose that irradiation can be successfully employed to improve the safety of frozen trimmings when initial pathogenic bacteria burdens are not extremely high.     

pH Dependent Molecular Self-Assembly of Octaphosphonate Porphyrin of Nanoscale Dimensions: Nanosphere and Nanorod Aggregates

Self-assembled nanostructures of zwitterionic octaphosphanatoporphyrin 1, of either nanoparticles or nanorods, depending on small changes in the pH, is demonstrated based on the J-aggregates. Porphyrin 1 self-assembled into nanosphere aggregates with a diameter of about 70-80 nm in the pH range 5-7, and nanorod aggregates were observed at pH 8.5. Hydrogen bonding, π-π stacking and hydrophilic interactions play important roles in the formation of this nanostructure morphology. Nanostructures were characterized by UV/Vis absorbance, fluorescence, atomic force microscopy (AFM) and transmission electron microscopy (TEM). This interesting pH dependent self-assembly phenomenon could provide a basis for development of novel biomaterials.     

Nutritional knowledge and consumption frequency of foods--a case study

The relationship between nutritional knowledge and the consumption frequency of preferred food-types was studied among one sample of Uruguayan consumers. A locally-adapted version of Parmenter & Wardle's General Nutrition Knowledge Questionnaire and a food consumption survey based on 39 food groups were completed by a total of 270 participants. Cluster Analysis enabled the identification of two clusters showing different levels of nutritional knowledge--cluster 1 (n = 177) and cluster 2 (n = 93), providing an average of 73.6% and 52.9% of correct answers, respectively. These clusters differed significantly (p < or = 0.05) in age and educational distribution--cluster 1 was composed mainly by older adults and persons with a higher educational level. A number of areas were identified where nutritional knowledge was extremely poor, as was the case with the recommended daily fruit and vegetable intake and the caloric content of the nutrients. Overall, nutritional knowledge was found to have a positive influence on food preferences and consumption frequency, those participants with a higher nutritional knowledge reporting a higher consumption of fruits, vegetables and low-fat products, in addition to a lower consumption of high-fat and high-sugar foods.     

Electrochemical oxidation of methyl orange azo dye at pilot flow plant using BDD technology

Solutions of methyl orange azo dye were degraded by electrochemical oxidation using a 3 L flow plant with a boron-doped diamond (BDD)/stainless steel cell operating at constant current density, ambient temperature and liquid flow rate of 12 L min^?1. A 2³ factorial design considering the applied current density, azo dye concentration and electrolysis time as variable independents was used to analyze the process by response surface methodology. LC–MS analysis revealed the formation of seven oxidation products from the cleavage of the NN group of the dye, followed by deamination, formation of a nitro group and/or desulfonation of the resulting aromatics.     

Enhanced oil recovery by means of alkali injection. Behavior of the SARA fractions

Abstract

The presence of an alkali such as sodium hydroxide (NaOH) within a process of enhanced recovery of crude oil having certain acidity allows the formation of surfactants with the ability of enhancing the separation of the crude oil from the reservoir rock where it is adsorbed due to a change of wettability. This work focused on studying the effect of NaOH on the enhanced recovery, in terms of the SARA composition, of two different API gravity crude oils (38.5 and 24.1°) having different total acid number. The results showed the existence of acid components with high and low reactivity to NaOH in the crude oil, where the first group is responsible of the in-situ synthesis of the surfactant. Moreover, it was found that the utilization of the alkali improved the recovery of the SARA fractions for each crude oil, especially for the 24.1°API crude oil for which the recovery resulted twice or three times higher to the evaluated for the 38.5°API crude oil. Additionally, it was found that a minimum of 0.2?wt% of NaOH reduced up to 4 times the value of the interfacial tension between the crude oil and the brine, regardless of the type of crude oil.     

Evaluation of ability of ferulic acid to control growth and fumonisin production of Fusarium verticillioides and Fusarium proliferatum on maize based media

The aim of this study was to evaluate the efficacy of ferulic acid (1, 10, 20 and 25 mM) at different water activity (a_w) values (0.99, 0.98, 0.96 and 0.93) at 25 °C on growth and fumonisin production by Fusarium verticillioides and Fusarium proliferatum on maize based media. For both Fusarium species, the lag phase significantly decreased (p ≤ 0.001), and the growth rates increased (p ≤ 0.001) at the lowest ferulic acid concentration used (1 mM), regardless of the a_w. However, high doses of ferulic acid (10 to 25 mM) significantly reduced (p ≤ 0.001) the growth rate of both Fusarium species, regardless of the a_w. In general, growth rate inhibition increased as ferulic acid doses increased and as media a_w decreased. Fumonisin production profiles of both Fusarium species showed that low ferulic acid concentrations (1–10 mM) significantly increased (p ≤ 0.001) toxin production, regardless of the a_w. High doses of ferulic acid (20–25 mM) reduced fumonisin production, in comparison with the controls, by both Fusarium species but they were not statistically significant in most cases. The results show that the use of ferulic acid as a post-harvest strategy to reduce mycotoxin accumulation on maize needs to be discussed.     

Functional goat milk cheese with feruloyl esterase activity

The aim of this paper was to evaluate the effect of the intake of goat milk cheese manufactured with Lactobacillus fermentum CRL1446 on intestinal feruloyl esterase (FE) activity and oxidative status in Swiss albino mice. This strain was used as single-strain culture (CRL cheese) and in combination with starter culture (Mix cheese). In both cheeses, L. fermentum reached 8–9 log cfu/g and FE activity increased during ripening. Highest activity level was observed in Mix cheese. In vivo studies showed that total intestinal FE activity in mice fed with CRL and Mix cheeses increased 1.5 and 2-fold compared to non-treated mice, respectively. Administration of Mix cheese produced a 2-fold increase in FE activity in small and large intestine mucosa. Mice receiving this cheese also showed an approx. 2-fold decrease in plasmatic thiobarbituric acid-reactive substances (TBARS) levels and an approx. 3-fold increase in glutathione reductase (GR) activity.Goat milk cheese elaborated with FE-producing strain L. fermentum CRL1446 could represent a novel functional food with FE activity, responsible for increasing intestinal FE activity and consequently the bioavailability of antioxidant ferulic acid in the gut, thus enhancing the oxidative status and providing protection against oxidative stress-related disorders.