Development of a rapid low cost fluorescent biosensor for the detection of food contaminants

A prototype fluorescent based biosensor has been developed for the antibody based detection of food related contaminants. Its performance was characterised and showed a typical antibody binding signal of 200-2000 mV, a short term noise of 9.1 mV, and baseline slope of -0.016 mV/s over 4 h. Bulk signal detection repeatability (n=23) and reproducibility (n=3) were less than 2.4%CV. The biosensor detection unit was evaluated using two food related model systems proving its ability to monitor both binding using commercial products and inhibition through the development of an assay. This assay development potential was evaluated by observing the biosensor's performance whilst appraising several labelled antibody and glass slide configurations. The molecular interaction between biotin and an anti-biotin antibody was shown to be inhibited by 41% due to the presence of biotin in a sample. A food toxin (domoic acid) calibration curve was produced, with %CVs ranging from 2.7 to 7.8%, and a midpoint of approximately 17 ng/ml with further optimisation possible. The ultimate aim of this study was to demonstrate the working principles of this innovative biosensor as a potential portable tool with the opportunity of interchangeable assays. The biosensor design is applicable for the requirements of routine food contaminant analysis, with respect to performance, functionality and cost. (C) 2012 Elsevier B.V. All rights reserved.

Peroxide-based hybrid and prodrug antimalarials to deliver cysteine protease inhibitors into the parasitic food vacuole

Tese de doutoramento, Farmácia (Química Farmacêutica e Terapêutica), Universidade de Lisboa, Faculdade de Farmácia, 2014

Are we wasting our money on food supplements in elder care wards?

Background. It is reported that undernutrition in older hospitalized patients is commonly found, but estimates of its prevalence vary. It is also not clear which treatment approaches are best because poor methodology prevents comparison of outcomes between different studies. Rationale. The rationale of this observational study was to look at typical elder care wards in order to determine what food supplements were being prescribed. We wished to determine whether serum albumin and/or body mass index (BMI) were appropriately related to the prescription of sip feeds and also to determine the palatability of supplements provided. Method. We monitored the wastage of sip feeds over a 24-hour period and extrapolated an estimated cost. Ninety-six patients were studied, including 23 patients with a BMI of less than 20, of whom 30% were on supplementary feeds. Results. Seventy percentage of prescribed sip feeds were being given to people with a BMI of 20 or more. The mean wastage in this 24-hour period was 63% (pound79.56) in four wards containing 96 older patients. Conclusion. We concluded that there was no relationship between the numbers of patients with a low albumin and BMI and the prescription of sip feeds. We found compliance to be low (37%) because of poor palatability, with a large number of patients who appeared to require sip feeds not being prescribed them and those who received them wasting more than they drank.

HACCP plan proposal for a typical Brazilian peanut processing company

Peanuts are likely to be infested by fungi with consequent contamination by aflatoxin in post-harvest industries. A hazard analysis critical control point (HACCP) plan is proposed for a typical Brazilian post-harvest industry from raw in-shell reception to the unpeeled peanuts transportation. Codex Alimentarius Commission guidelines were followed, with four critical control points (CCP) for aflatoxin being identified. The process steps with highest probability of aflatoxin occurrence (risk) are the in-shell reception, the dried in-shell storage, and the unpeeled kernel storage. During the storage steps there is a lack of control of air moisture and temperature. Therefore, there is no option but to keep rigid monitoring and control over each CCP, and detour lots with high aflatoxin levels to either oil or seed production. Attempts to correlate the aflatoxin levels with the rainfall showed an irregular trend of the toxin level. (c) 2008 Elsevier Ltd. All rights reserved.

Friction losses in valves and fittings for liquid food products

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Food intake and nutritional status of hospitalised older people

Background and aims. Disease is influenced by the nutritional status of the individual. We have assessed the relationship between nutritional status and food intake among recently hospitalised older people. Methods. A cross-sectional study was undertaken with 240 older people in a hospital that provides care for the public and private healthcare systems. Nutritional status was classified by the MNA (Mini Nutritional Assessment) into: malnourished, risk of malnutrition and without malnutrition. Food intake was estimated by the reported food intake during a typical day. The Kruskal-Wallis test was used to compare the medians and the correlation coefficient of Spearman to verify the relationship between the consumption of energy, protein and vitamin C and MNA scores. Results. 33.8% were classified as adequate regarding nutritional status; 37.1% were classified as being at risk of malnutrition and 29.1% were classified as malnourished. The malnourished individuals reported significantly less energy and nutrient intake than those at risk of malnutrition or those without malnutrition (P=0.001). Not all nutrient intake, just some (iron, cholesterol and fibre), were lower in malnourished people. Conclusions and implications for practice. Deterioration of the nutritional status of older people is accompanied by a reduction in energy and some nutrient intake. The investigation of food intake in older people could provide important information about nutritional risk. © 2010 Blackwell Publishing Ltd.

Assessment of the risk of raw milk consumption related to staphylococcal food poisoning

This study aimed to identify the risks of staphylococcal food poisoning due to the consumption of raw milk. Fifty-one farms in Londrina (PR) and 50 in Pelotas (RS) were analyzed, to determine the population of coagulase-positive staphylococci (UFC/ mL), as well as to verify the ability of producing Staphylococcal Enterotoxin A (SEA) by immunodifusion (OSP), the presence of the gene for the production of SEA (PCR) in the cultures, and the research of enterotoxin (SEA to SEE) in milk samples using ELISA commercial kit. Considering the 101 farms analyzed, 19 (18.8%) presented coagulase-positive staphylococci count above 105 UFC/mL. For the evaluation of the enterotoxigenic ability (SEA) by the OSP technique, six cultures coagulase-positive (5.5%) were positive to the test and identified as S. aureus. From the coagualse-negative sample, one (5.5%) was OSP positive. For the evaluation of the presence of the gene for EEA synthesis, 51 cultures of staphylococci were tested. From this total, 14 (27.45%) presented the gene, and from that, only 5 (9.81%) cultures were capable of expressing it in the technique of the OSP. The morphologic characteristic of the evaluated cultures that had enterotoxigenic capacity, from the 14 (33,3%) cultures that presented the gene for EEA production, 05 (11.9%) were characterized as typical cultures of S.aureus in Baird Parker agar. All the 12 milk samples studied for the presence of EEA to EEE in milk were negative. Thus, it can be concluded that there is extensive contamination of raw milk for staphylococci coagulase, however, most of the isolated strains were not enterotoxigenic or did not express such a characteristic. Only 9.81% of the tested colonies expressed the gene and effectively produced SEA. None of the samples had sufficient counts to produce detectable amounts of SEA. The milk samples did not present risk to cause staphylococcal food poisoning if consumed in natura until the collection moment.

Perceived risks in cross-border transactions in agri-food chains

Nowadays, agri-food chains are more global than ever and are characterized by increased imports and exports and global sourcing of products, resulting in increased cross-border transaction risks. The objective of this paper is to identify the typical risks regarding agri-food supply chains involved in cross-border transactions and to assess their importance as perceived by agri-food managers. The analysis takes into consideration four different agrifood value chains (meat, grain, olive oil, fresh vegetables and fruits). Following an explorative approach and a qualitative technique, a series of face to face in-depth interviews was conducted. Results indicate that risk perception may be quite different across countries, value chains, tiers of the supply chain, as well as across respondents. The prevalence of Market dynamics risks was pointed out in most of the interviews, yielding the impression that many operators identify the market as the most difficult environment. Differences in risk perception between fresh produce (fruit/vegetables and meat) and processed food chains (grain and olive oil) are probably interrelated to the different degree of integration within these supply chains, the different level of standardization achieved and the different causes of risks that are inherent to the nature of the product.

The importance of mealtime structure for reducing child food fussiness

The aim of this study was to explore how the structure of mealtimes within the family setting is related to children's fussy eating behaviours. Seventy-five mothers of children aged between 2 and 4 years were observed during a typical mealtime at home. The mealtimes were coded to rate mealtime structure and environment as well as the child's eating behaviours (food refusal, difficulty to feed, eating speed, positive and negative vocalisations). Mealtime structure emerged as an important factor which significantly distinguished children with higher compared with lower levels of food fussiness. Children whose mothers ate with their child and ate the same food as their child were observed to refuse fewer foods and were easier to feed compared with children whose mothers did not. During mealtimes where no distractors were used (e.g. no TV, magazines or toys), or where children were allowed some input into food choice and portioning, children were also observed to demonstrate fewer fussy eating behaviours. Findings of this study suggest that it may be important for parents to strike a balance between structured mealtimes, where the family eats together and distractions are minimal, alongside allowing children some autonomy in terms of food choice and intake.

Recreational Food Service is Big Business

In the analysis - Recreational Food Service Is Big Business - by Gary Horvath, President, Recreational Foodservice Division, Service America Corporation and Mickey Warner, Associate Professor School of Hospitality Management at Florida International University, Horvath and Warner initially state: “Recreational food service is very different from routine food service management. The authors review the market and the management planning and challenges that create that difference.” Recreational food is loosely defined by the authors as food for special events. These can be one-time events, repeated events that are not on a fixed schedule [i.e. concerts], weekly events such as football-baseball-or basketball games, or other similar venues. Concessions are a large part of these fan based settings. “An anticipated 101,000 fans at a per capita spending of $5-6 [were expected]. A typical concessions menu of hot dogs, popcorn, soda, beer, snacks, novelty foods, candy, and tobacco products comprises this market segment,” say Horvath and Warner in reference to the Super-Bowl XXI football championship game, held in Rose Bowl stadium in Pasadena, California, on January 25, 1987. Some of the article is based upon that event. These food service efforts focus on the individual fan, but do extend to the corporate-organizational level as well. Your authors will have you know that catering is definitely a part of this equation. The monies spent and earned are phenomenal. “Special events of this type attract numerous corporate catering opportunities for companies entertaining VIP guest lists,” the authors inform. “Hospitality tents usually consist of a pregame cocktail party and buffet and a post-game celebration with musical entertainment held in lavishly decorated tents erected at the site. In this case a total of 5,000 covers, at a price of $200 each, for 12-15 separate parties were anticipated.” Horvath and Warner also want you to know that novelties and souvenirs make up an essential part of this, the recreational food service market. “Novelties and souvenirs are a primary market and source of revenue for every stadium food service operator,” say Horvath and Warner. The term, “per capita spending is the measurement used by the industry to evaluate sales potential per attendee at an event,” say the authors. Of course, with the solid revenue figures involved as well as the number of people anticipated for such events, planning is crucial, say Horvath and Warner. Training of staff, purchasing and supply, money and banking, facility access, and equipment, are a few of the elements to be negotiated. Through both graphs and text, Horvath and Warner do provide a fairly detailed outline of what a six-step event plan consists of.

Personal Style of On-Site Food Service Managers

Myers-Briggs Type Indicators (MBTI) assess preferences based on Carl Jungs theory of psychological types. They are widely used in organizational development, management and leadership training, and team building. This study examines MBTl of food service managers in a single organization to determine whether food service managers have a typical personal style and whether this style varies.

Functional application of lactic acid bacteria exopolysaccharide in complex food systems

Lactic acid bacteria expolysaccharides (LAB-EPS), in particular those formed from sucrose have the potential to improve food and beverage rheology and enhance their sensory properties potentially replacing or reducing expensive hydrocolloids currently used as improvers in food and beverage industries. Addition of sucrose not only enables EPS formation but also affects organic acid formation, thus influencing the sensory properties of the resulting food/beverage products. The first part of the study the organoleptic modulation of barley malt derived wort fermented using in situ produced bacterial polysaccharides has been investigated. Weisella cibaria MG1 was capable to produce exopolysaccharides during sucrosesupplemented barley malt derived wort fermentation. Even though the strain dominated the (sucrose-supplemented) wort fermentation, it was found to produce EPS (14.4 g l-1) with lower efficiency than in SucMRS (34.6 g l-1). Higher maltose concentration in wort led to the increased formation of oligosaccharide (OS) at the expense of EPS. Additionally, small amounts of organic acids were formed and ethanol remained below 0.5% (v/v). W. cibaria MG1 fermented worts supplemented with 5 or 10% sucrose displayed a shear-thinning behaviour indicating the formation of polymers. This report showed how novel and nutritious LAB fermented wort-base beverage with prospects for further advancements can be formulated using tailored microbial cultures. In the next step, the impact of exopolysaccharide-producing Weissella cibaria MG1 on the ability to improve rheological properties of fermented plant-based milk substitute plant based soy and quinoa grain was evaluated. W. cibaria MG1 grew well in soy milk, exceeding a cell count of log 8 cfu/g within 6 h of fermentation. The presence of W. cibaria MG1 led to a decrease in gelation and fermentation time. EPS isolated from soy yoghurts supplemented with sucrose were higher in molecular weight (1.1 x 108 g/mol vs 6.6 x 107 g/mol), and resulted in reduced gel stiffness (190 ± 2.89 Pa vs 244 ± 15.9 Pa). Soy yoghurts showed typical biopolymer gels structure and the network structure changed to larger pores and less cross-linking in the presence of sucrose and increasing molecular weight of the EPS. In situ investigation of Weissella cibaria MG1 producing EPS on quinoa-based milk was performed. The production of quinoa milk, starting from wholemeal quinoa flour, was optimised to maximise EPS production. On doing that, enzymatic destructuration of protein and carbohydrate components of quinoa milk was successfully achieved applying alpha-amylase and proteases treatments. Fermented wholemeal quinoa milk using Weissella cibaria MG1 showed high viable cell counts (>109 cfu/mL), a pH of 5.16, and significantly higher water holding capacity (WHC, 100 %), viscosity (> 0. 5 Pa s) and exopolysaccharide (EPS) amount (40 mg/L) than the chemically acidified control. High EPS (dextran) concentration in quinoa milk caused earlier aggregation because more EPS occupy more space, and the chenopodin were forced to interact with each other. Direct observation of microstructure in fermented quinoa milk indicated that the network structures of EPS-protein could improve the texture of fermented quinoa milk. Overall, Weissella cibaria MG1 showed favorable technology properties and great potential for further possible application in the development of high viscosity fermented quinoa milk. The last part of the study investigate the ex-situ LAB-EPS (dextran) application compared to other hydrocolloids as a novel food ingredient to compensate for low protein in biscuit and wholemeal wheat flour. Three hydrocolloids, xanthan gum, dextran and hydroxypropyl methylcellulose, were incorporated into bread recipes based on high-protein flours, low-protein flours and coarse wholemeal flour. Hydrocolloid levels of 0–5 % (flour basis) were used in bread recipes to test the water absorption. The quality parameters of dough (farinograph, extensograph, rheofermentometre) and bread (specific volume, crumb structure and staling profile) were determined. Results showed that xanthan had negative impact on the dough and bread quality characteristics. HPMC and dextran generally improved dough and bread quality and showed dosage dependence. Volume of low-protein flour breads were significantly improved by incorporation of 0.5 % of the latter two hydrocolloids. However, dextran outperformed HPMC regarding initial bread hardness and staling shelf life regardless the flour applied in the formulation.