Evaluation of a new mathematical model to describe Clostridium perfringens growth during the cooling of cooked ground beef

A mathematical model previously developed to study microbial growth in food products under an isothermal environment was adapted to a time-varying temperature regime. The resulting model was applied to study the growth of Clostridium perfringens in meat products. This micro-organism is of particular relevance to public health and economy due to the loss of productivity caused by it. Results showed a similar performance of the model used compared to the Baranyi model under an isothermal situation and a slightly better performance under a non-isothermal temperature profile.

Chemical constituents and technological functional properties of acerola (Malpighia emarginata DC.) waste flour

Acerola is a fruit that can be consumed in the form of juice and pulp. However, during its processing, a large amount of waste is generated (seed and bagasse). Adding value to these by-products is of great interest, since their use can enrich foods with nutrients and fiber. In this study, we performed phytochemical screening, determined the proximate and mineral composition, bioactive compounds and the technological functional properties of acerola seed flour and acerola bagasse flour. Seeds were dried in a ventilated oven at ± 45 °C and the bagasse was lyophilized. Samples were ground, stored in flasks protected from light. Phytochemical screening revealed metabolites of nutritional and pharmacological interest and no potentially toxic substances in the flours. Seed flour and bagasse flour showed high levels (g 100 g- 1 of dry matter - DM) of soluble fiber: 4.76 and 8.74; insoluble fiber: 75.76 and 28.58, and phenolic compounds: 4.73 and 10.82, respectively. The flours also showed high absorption of water, oil and emulsion stability, presenting potential for inclusion in meat products and bakery products.

Profile of establishments in the supermarket sector with respect to good practices in the city of Santa Maria (RS), Brazil

The objective of this study was to verify the compliance of the supermarket sector with respect to the Good Practice Program standards of the city of Santa Maria (RS), Brazil. Sixty nine establishments were verified using a checklist of good practices for the supermarket sector in Santa Maria, RS (Brazil), from April to July 2011. The data were collected by a food safety and quality professional using this checklist. The results showed that the overall adequacy of the establishments surveyed was 29.07%. The highest percentage of compliance was found for storage at ambient temperature (64.13%). The lowest compliance percentage was also found in different sections and areas in the supermarkets such as bakery and confectionery (14.93%), water supply (18.30%), food handling (21.01%), sausage and cold meat (or deli meat) (36.38%), and documentation-related items (4.97%). None of the supermarkets evaluated had the necessary documentation for the implementation of good practices. The results of this study show the importance of effectively implementing a good practice program and quality systems by raising awareness among technicians and professionals of the importance of quality programs used in food companies and the need for more thorough inspection delivered by competent authorities to ensure food safety for consumers.

Heavy metals investigation in bovine tissues in Brazil

The aim of this study was to investigate the presence of arsenic, lead, and cadmium residues in samples of liver, kidney, and muscle of cattle during the years of 2002 to 2008. A total of 1017 samples from 20 Brazilian States were used. The samples were analyzed at the National Agricultural Laboratory using the atomic absorption spectrometry technique. Arsenic residues were detected in 15.7% of liver samples and 28.7% of kidney samples although no results have exceeded the MRL. With regard to lead, 16 samples of liver and 74 samples of kidney were contaminated (5.2 and 10.9%, respectively). Among these samples, only one liver and two of kidney samples had lead levels above the MRL. Cadmium was found with levels below the MRL in 12.5% of the liver samples, and only 3 samples (1%) were quantified above the MRL. Among the kidney samples, 420 (60.8% of the total tested) had cadmium residues, and five of them exceeded the limits established by legislation. It is concluded that the Brazilian meat meets the legislation requirements without putting consumer's healthy at risk since as it satisfies the national and international food-safety conditions.

Effects of sequential enzymatic hydrolysis on structural, bioactive and functional properties of Phaseolus lunatus protein isolate

Significant initiatives exist within the global food market to search for new, alternative protein sources with better technological, functional, and nutritional properties. Lima bean (Phaseolus lunatus L.) protein isolate was hydrolyzed using a sequential pepsin-pancreatin enzymatic system. Hydrolysis was performed to produce limited (LH) and extensive hydrolysate (EH), each with different degrees of hydrolysis (DH). The effects of hydrolysis were evaluated in vitro in both hydrolysates based on structural, functional and bioactive properties. Structural properties analyzed by electrophoretic profile indicated that LH showed residual structures very similar to protein isolate (PI), although composed of mixtures of polypeptides that increased hydrophobic surface and denaturation temperature. Functionality of LH was associated with amino acid composition and hydrophobic/hydrophilic balance, which increased solubility at values close to the isoelectric point. Foaming and emulsifying activity index values were also higher than those of PI. EH showed a structure composed of mixtures of polypeptides and peptides of low molecular weight, whose intrinsic hydrophobicity and amino acid profile values were associated with antioxidant capacity, as well as inhibiting angiotensin-converting enzyme. The results obtained indicated the potential of Phaseolus lunatus hydrolysates to be incorporated into foods to improve techno-functional properties and impart bioactive properties.

Physicochemical and sensory characteristics of snack made with minced Nile tilapia

Nile tilapia is one of the major fish species cultivated worldwide and in Brazil. The tilapia fillet yield is between 30-35%, thus around 70% of waste is generated. A portion of this waste can be used to obtain minced fish, and the resulting product can be used as meat raw material to prepare fish snacks. The aim of this study was to produce fish snacks containing different inclusion levels (20, 30, and 40%) of minced fish obtained from Nile tilapia processing waste and evaluate their physicochemical characteristics and sensory acceptance. Protein content, ash, water activity, and hardness increased with increasing inclusion of minced fish. The scores obtained in the sensory evaluation were: flavor acceptance (from 7.2 to 5.7), texture (from 7.4 to 5.3), overall acceptance (from 7.1 to 5.9), and willingness to purchase (from 4.0 to 3.1). This study demonstrates that the inclusion of 20 to 40% of minced fish of Nile tilapia in snacks is well accepted and improves their nutritional value without affecting the physicochemical properties.

Use of starter cultures isolated from native microbiota of artisanal sausage in the production of Italian sausage

The most promising microorganisms for use as starter cultures are those isolated from the native microbiota of traditional fermented products. The aim of this study was to evaluate the use of lactic acid bacteria selected from the native microbiota of sausages produced by spontaneous fermentation as starter cultures for the production of sausage. Strains of Lactobacillus plantarum 503 and 341 have the potential for use as starter cultures in the manufacture of Italian sausage type. The population of lactic acid bacteria in sausages was >8 log CFU.g-1 during fermentation, which caused the pH to decrease to <4.5. This decrease in pH and the water activity of < 0.90 of sausages ensures the safety and preservation of this product. Sausages produced with these lactic cultures fulfill the requirements for microbiological quality and composition of Italian sausage type. Our results suggest the possibility of using these starter cultures for the production of sausages with peculiar characteristics that contribute to the identity of the product.

Screening and kinetics of glutaminase and glutamate decarboxylase producing lactic acid bacteria from fermented Thai foods

L-glutaminase and glutamic acid decarboxylase (GAD) catalyzes the hydrolysis of L-glutamine and glutamate, respectively. L-glutaminase widely used in cancer therapy along with a combination of other enzymes and most importantly these enzymes were used in food industries, as a major catalyst of bioconversion. The current investigation was aimed to screen and select L-glutaminase, and GAD producing lactic acid bacteria (LAB). A total of 338 LAB were isolated from fermented meat, fermented fish, fermented soya bean, fermented vegetables and fruits. Among 338 isolates, 22 and 237 LAB has been found to be positive for L-glutaminase and GAD, respectively. We found that 30 days of incubation at 35 ºC and pH 6.0 was the optimum condition for glutaminase activity by G507/1. G254/2 was found to be the best for GAD activity with the optimum condition of pH 6.5, temperature 40 ºC and ten days of incubation. These LAB strains, G507/1 and G254/2, were identified as close relative of Lactobacillus brevis ATCC 14869 and Lactobacillus fermentum NBRC 3956, respectively by 16S rRNA sequencing. Further, improvements in up-stream of the fermentation process with these LAB strains are currently under development.

Fish consumption preferences and factors influencing it

Fish consumption preferences are affected by individuals’ socioeconomic characteristics. The aims of the present paper were (i) to obtain information on fish consumption level and frequency; (ii) to investigate the associations between the socioeconomic characteristics of consumers and their preferences; and (iii) to examine the influence of determinants on fish consumption. Data were gathered through a questionnaire completed by a total of 127 randomly selected individuals from different socioeconomic backgrounds from the Antakya, Turkey. The average consumption was found to be 2.98 kg/person/year for fish. Anchovies, gilt-head sea bream, and sea bass were reported as the most consumed three species, respectively. Significant differences in fish consumption were found among age groups, gender groups, and education groups, as well as between marital statuses. A majority of the consumers eat fish once a month throughout the year or only during the winter months. Fish consumption level and frequency were significantly positively correlated with education (p<0.01), income (p<0.05) and total meat consumption (p<0.01). The stepwise multiple regression model explained 41.7% (p<0.01) of the total variance for fish consumption. The amount and frequency of the consumption in the region, which is very far below the world and Turkey average especially for lower socioeconomic groups and for less-consumed fish species, can be increased by certain policies, such as training, advertising and different marketing strategies. Moreover, consumption should be distributed equally throughout the year instead of consuming only in certain seasons.

Physical, chemical and sensory properties of gluten-free kibbeh formulated with millet flour (Pennisetum glaucum (L.) R. Br.)

Pearl millet flour was utilized in kibbeh formulations instead of whole-wheat flour. Physicochemical properties, oxidation stability and sensorial characteristics of control kibbeh made with whole-wheat flour (CT) were compared with kibbehs prepared with millet flour (roasted or wet) and stored for 90 days (–18 °C). Kibbeh prepared with millet flour presented good oxidation stability (TBARS concentration). Baked kibbehs (with roasted millet flour) presented good acceptability and kibbeh samples did not differ significantly (p > 0.05) from the whole-wheat flour sample, when global appearance, texture and flavor were evaluated. Millet flour could be a suitable ingredient for kibbeh formulations, maintaining their nutritional value and sensorial quality in addition to being a gluten-free product.