Contamination routes and control of Listeria monocytogenes in Food Production

Listeria monocytogenes is the causative agent of the severe foodborne infection listeriosis. The number of listeriosis cases in recent years has increased in many European countries, including Finland. Contamination of the pathogen needs to be minimized and growth to high numbers in foods prevented in order to reduce the incidence of human cases. The aim of this study was to evaluate contamination routes of L. monocytogenes in the food chain and to investigate methods for control of the pathogen in food processing. L. monocytogenes was commonly found in wild birds, the pig production chain and in pork production plants. It was found most frequently in birds feeding at landfill site, organic farms, tonsil samples, and sites associated with brining. L. monococytogenes in birds, farms, food processing plant or foods did not form distinct genetic groups, but populations overlapped. The majority of genotypes recovered from birds were also detected in foods, food processing environments and other animal species and birds may disseminate L. monocytogenes into food chain. Similar genotypes were found in different pigs on the same farm, as well as in pigs on farms and later in the slaughterhouse. L. monocytogenes contamination spreads at farm level and may be a contamination source into slaughterhouses and further into meat. Incoming raw pork in the processing plant was frequently contaminated with L. monocytogenes and genotypes in raw meat were also found in processing environment and in RTE products. Thus, raw material seems to be a considerable source of contamination into processing facilities. In the pork processing plant, the prevalence of L. monocytogenes increased in the brining area, showing that the brining was an important contamination site. Recovery of the inoculated L. monocytogenes strains showed that there were strain-specific differences in the ability to survive in lettuce and dry sausage. The ability of some L. monocytogenes strains to survive well in food production raises a challenge for industry, because these strains can be especially difficult to remove from the products and raises a need to use an appropriate hurdle concept to control most resistant strains. Control of L. monocytogenes can be implemented throughout the food chain. Farm-specific factors affected the prevalence of L. monocytogenes and good farm-level practices can therefore be utilized to reduce the prevalence of this pathogen on the farm and possibly further in the food chain. Well separated areas in a pork production plant had low prevalences of L. monocytogenes, thus showing that compartmentalization controls the pathogen in the processing line. The food processing plant, especially the brining area, should be subjected to disassembling, extensive cleaning and disinfection to eliminate persistent contamination by L. monocytogenes, and replacing brining with dry-salting should be considered. All of the evaluated washing solutions decreased the populations of L. monocytogenes on precut lettuce, but did not eliminate the pathogen. Thus, the safety of fresh-cut produce cannot rely on washing with disinfectants, and high-quality raw material and good manufacturing practices remain important. L. monocytogenes was detected in higher levels in sausages without the protective culture than in sausages with this protective strain, although numbers of L. monocytogenes by the end of the ripening decreased to the level of < 100 MPN/g in all sausages. Protective starter cultures provide an appealing hurdle in dry sausage processing and assist in the control of L. monocytogenes.

Analysis of co-current hydraircooling of food products in bulk

A mathematical model is developed to describe the hydraircooling process when the water and air are flowing in the same direction. The governing equations for the simultaneous heat and mass transfer are solved using finite-difference numerical methods. The half cooling time of the food products is correlated as a function of the dimensionless process parameters. It is observed that a process time of approximately double the half cooling time will result in the food products attaining almost a steady state. The process times of the bulk hydraircooling process and the bulk air precooling process are compared.

Consumers' attitudes towards food prices

High food prices can be a barrier to healthy eating because some of the food products may be perceived as expensive. Understanding the role of price in food purchase situations is important, but only a few studies document attitudes towards expensiveness or cheapness in foods. In this thesis, the role of food price in food choice and consumers attitudes towards food prices were investigated and the aim was to measure the food price attitudes. Food price attitudes were hypothesized to have an impact on consumers willingness to pay judgements and their willingness to buy premium-priced food products. First, using qualitative data consisting of 40 thematic interviews the experiences of the expensiveness and cheapness in foods were explored by using functional food products as a target product category. Second, a Food Price Attitude Scale was developed using four quantitative surveys representing Finnish consumers (2001 N=1158; 2002 N=1156; 2004a N=1113; 2004b N=1027). Food price attitudes were confirmed to compose a multidimensional construct and consumers may perceive positive and negative attitudes towards both high and low food prices. Finnish consumers were clustered into four groups based on their food price attitudes. In the first group, 29% of respondents were negative towards high food prices and they were willing to seek low food prices, whereas respondents in another group (22%) were positive towards high food prices. Additionally, in the third group consumers (17%) were willing to pay for high quality but still looked for low food prices. In the fourth group, consumers (32%) were willing to look for low food prices, unwilling to pay for high quality, but high-priced food was appreciated if offered to others. It was found in qualitative data that consumers willingness to accept high prices in foods was connected to price fairness and to justifications. Feelings of fairness or unfairness might be a core element of food price attitudes. Using quantitative methods, it was confirmed that positive attitudes towards high food prices in terms of high quality enhanced consumers willingness to buy food products with certain benefits (e.g., a health claim). Additionally, the favourable attitude towards low food prices lowered the willingness to pay estimates. This type of tendency, however, can create a possible bias in small convenient samples. In the food price-related research, it is advisable to take into account food price attitudes as possible background variables. The Food Price Attitude Scale needs further development to increase construct validity even though, in the present study, it was shown to be a reliable measure with good predictive and discriminant validity. The theoretical and managerial implications of the results for a better understanding of the role of price in consumers food purchases are discussed.

Analysis of heat and mass transfer during bulk hydraircooling of spherical food products

Hydraircooling is a technique used for precooling food products. In this technique chilled water is sprayed over the food products while cold unsaturated air is blown over them. Hydraircooling combines the advantages of both air- and hydrocooling. The present study is concerned with the analysis of bulk hydraircooling as it occurs in a package filled with several layers of spherical food products with chilled water sprayed from the top and cold unsaturated air blown from the bottom. A mathematical model is developed to describe the hydrodynamics and simultaneous heat and mass transfer occurring inside the package. The non-dimensional governing equations are solved using the finite difference numerical methods. The results are presented in the form of time-temperature charts. A correlation is obtained to calculate the process time in terms of the process parameters.

The Effect of Food-Related Lifestyle on the Choices of Consumers of Five Food Products

The purpose of this study was to find out whether food-related lifestyle guides and explains product evaluations, specifically, consumer perceptions and choice evaluations of five different food product categories: lettuce, mincemeat, savoury sauce, goat cheese, and pudding. The opinions of consumers who shop in neighbourhood stores were considered most valuable. This study applies means-end chain (MEC) theory, according to which products are seen as means by which consumers attain meaningful goals. The food-related lifestyle (FRL) instrument was created to study lifestyles that reflect these goals. Further, this research has adopted the view that the FRL functions as a script which guides consumer behaviour. Two research methods were used in this study. The first was the laddering interview, the primary aim of which was to gather information for formulating the questionnaire of the main study. The survey consisted of two separate questionnaires. The first was the FRL questionnaire modified for this study. The aim of the other questionnaire was to determine the choice criteria for buying five different categories of food products. Before these analyses could be made, several data modifications were made following MEC analysis procedures. Beside forming FRL dimensions by counting sum-scores from the FRL statements, factor analysis was run in order to elicit latent factors underlying the dimensions. The lifestyle factors found were adventurous, conscientious, enthusiastic, snacking, moderate, and uninvolved lifestyles. The association analyses were done separately for each choice of product as well as for each attribute-consequence linkage with a non-parametric Mann-Whitney U test. The testing variables were FRL dimensions and the FRL lifestyle factors. In addition, the relation between the attribute-consequence linkages and the demographic variables were analysed. Results from this study showed that the choice of product is sequential, so that consumers first categorize products into groups based on specific criteria like health or convenience. It was attested that the food-related lifestyles function as a script in food choice and that the FRL instrument can be used to predict consumer buying behaviour. Certain lifestyles were associated with the choice of each product category. The actual product choice within a product category then appeared to be a different matter. In addition, this study proposes a modification to the FRL instrument. The positive towards advertising FRL dimension was modified to examine many kinds of information search including the internet, TV, magazines, and other people. This new dimension, which was designated as being open to additional information, proved to be very robust and reliable in finding differences in consumer choice behaviour. Active additional information search was linked to adventurous and snacking food-related lifestyles. The results of this study support the previous knowledge that consumers expect to get many benefits simultaneously when they buy food products. This study brought detailed information about the benefits sought, the combination of benefits differing between products and between respondents. Household economy, pleasure and quality were emphasized with the choice of lettuce. Quality was the most significant benefit in choosing mincemeat, but health related benefits were often evaluated as well. The dominant benefits linked to savoury sauce were household economic benefits, expected pleasurable experiences, and a lift in self-respect. The choice of goat cheese appeared not to be an economic decision, self-respect, pleasure, and quality being included in the choice criteria. In choosing pudding, the respondents considered the well-being of family members, and indulged their family members or themselves.

Responsiveness of human male volunteers to immunization with ovine follicle stimulating hormone vaccine: Results of a pilot study

A study of 140 days duration was performed to examine if human male volunteers (n = 5) respond to ovine follicle stimulating hormone (oFSH) immunization (administered adsorbed on Alugel on days 1, 20, 40 and 70) by producing antibodies capable of both binding and neutralizing bioactivity of human FSH. The kinetics of antibody production for both the immunogen (oFSH) and the cross-reactive antigen (hFSH) were essentially similar, The volunteers responded only to the first two immunizations, The boosters given on days 40 and 70 were ineffective, probably because of the presence of substantial amounts of circulating antibody to oFSH. Of the antibodies generated to oFSH, 25-45% bound hFSH with a mean binding affinity of 0.65 x 10(9) +/- 0.53 M(-1). The binding capacities at the time of high (30-80 days of immunization) and low (>110 days) titres were 346 +/- 185 and 10.5 +/- 5.8 ng hFSH/ml respectively, During the period of high titre, free serum FSH (value in normal males 1-5 ng/ml) was not monitorable, A 50 mu l aliquot of the antiserum obtained from different volunteers between days 30 and 80 and on day 140 blocked binding of I-125-labelled hFSH to its receptor by 82 +/- 9.7 and 53 +/- 12.2% respectively, The antibody produced was specific for FSH, and no significant change in the values of related glycoprotein hormones (luteinizing hormone/testosterone and thyroid stimulating hormone/thyroxine) were recorded, Seminal plasma transferrin, a marker of Sertoli cell as well as of seminiferous tubular function, showed marked reduction (30-90%) following immunization with oFSH. Considering that endogenous FSH remained neutralized for approximately one sperm cycle only (65 days), the reduction in sperm counts (30-74%) exhibited by some volunteers is encouraging, Immunization with oFSH did not result in any significant changes in haematology, serum biochemistry or hormonal profiles, There was no production of antibodies capable of interacting with non-specific tissues, It is concluded that it should be possible to obtain a sustained long-term blockade of endogenous FSH action in men by using oFSH as an immunogen, This is a prerequisite for obtaining significant reduction in the quality and quantity of spermatozoa produced, thus leading to infertility.

Biofuel production and implications for land use, food production and environment in India

There is a large interest in biofuels in India as a substitute to petroleum-based fuels, with a purpose of enhancing energy security and promoting rural development. India has announced an ambitious target of substituting 20% of fossil fuel consumption by biodiesel and bioethanol by 2017. India has announced a national biofuel policy and launched a large program to promote biofuel production, particularly on wastelands: its implications need to be studied intensively considering the fact that India is a large developing country with high population density and large rural population depending upon land for their livelihood. Another factor is that Indian economy is experiencing high growth rate, which may lead to enhanced demand for food, livestock products, timber, paper, etc., with implications for land use. Studies have shown that area under agriculture and forest has nearly stabilized over the past 2-3 decades. This paper presents an assessment of the implications of projected large-scale biofuel production on land available for food production, water, biodiversity, rural development and GHG emissions. The assessment will be largely focused on first generation biofuel crops, since the Indian program is currently dominated by these crops. Technological and policy options required for promoting sustainable biofuel production will be discussed. (C) 2010 Elsevier Ltd. All rights reserved.

How much land-based greenhouse gas mitigation can be achieved without compromising food security and environmental goals?

Feeding 9-10billion people by 2050 and preventing dangerous climate change are two of the greatest challenges facing humanity. Both challenges must be met while reducing the impact of land management on ecosystem services that deliver vital goods and services, and support human health and well-being. Few studies to date have considered the interactions between these challenges. In this study we briefly outline the challenges, review the supply- and demand-side climate mitigation potential available in the Agriculture, Forestry and Other Land Use AFOLU sector and options for delivering food security. We briefly outline some of the synergies and trade-offs afforded by mitigation practices, before presenting an assessment of the mitigation potential possible in the AFOLU sector under possible future scenarios in which demand-side measures codeliver to aid food security. We conclude that while supply-side mitigation measures, such as changes in land management, might either enhance or negatively impact food security, demand-side mitigation measures, such as reduced waste or demand for livestock products, should benefit both food security and greenhouse gas (GHG) mitigation. Demand-side measures offer a greater potential (1.5-15.6Gt CO2-eq. yr(-1)) in meeting both challenges than do supply-side measures (1.5-4.3Gt CO2-eq. yr(-1) at carbon prices between 20 and 100US$ tCO(2)-eq. yr(-1)), but given the enormity of challenges, all options need to be considered. Supply-side measures should be implemented immediately, focussing on those that allow the production of more agricultural product per unit of input. For demand-side measures, given the difficulties in their implementation and lag in their effectiveness, policy should be introduced quickly, and should aim to codeliver to other policy agenda, such as improving environmental quality or improving dietary health. These problems facing humanity in the 21st Century are extremely challenging, and policy that addresses multiple objectives is required now more than ever.

Flexibility in Food Extraction Techniques in Urban Free-Ranging Bonnet Macaques, Macaca radiata

Non-human primate populations, other than responding appropriately to naturally occurring challenges, also need to cope with anthropogenic factors such as environmental pollution, resource depletion, and habitat destruction. Populations and individuals are likely to show considerable variations in food extraction abilities, with some populations and individuals more efficient than others at exploiting a set of resources. In this study, we examined among urban free-ranging bonnet macaques, Macaca radiata (a) local differences in food extraction abilities, (b) between-individual variation and within-individual consistency in problem-solving success and the underlying problem-solving characteristics, and (c) behavioral patterns associated with higher efficiency in food extraction. When presented with novel food extraction tasks, the urban macaques having more frequent exposure to novel physical objects in their surroundings, extracted food material from PET bottles and also solved another food extraction task (i.e., extracting an orange from a wire mesh box), more often than those living under more natural conditions. Adults solved the tasks more frequently than juveniles, and females more frequently than males. Both solution-technique and problem-solving characteristics varied across individuals but remained consistent within each individual across the successive presentations of PET bottles. The macaques that solved the tasks showed lesser within-individual variation in their food extraction behavior as compared to those that failed to solve the tasks. A few macaques appropriately modified their problem-solving behavior in accordance with the task requirements and solved the modified versions of the tasks without trial-and-error learning. These observations are ecologically relevant - they demonstrate considerable local differences in food extraction abilities, between-individual variation and within-individual consistency in food extraction techniques among free-ranging bonnet macaques, possibly affecting the species' local adaptability and resilience to environmental changes.

DNA STRUCTURAL FEATURES AND ARCHITECTURE OF PROMOTER REGIONS PLAY A ROLE IN GENE RESPONSIVENESS OF S. CEREVISIAE

Gene expression is the most fundamental biological process, which is essential for phenotypic variation. It is regulated by various external (environment and evolution) and internal (genetic) factors. The level of gene expression depends on promoter architecture, along with other external factors. Presence of sequence motifs, such as transcription factor binding sites (TFBSs) and TATA-box, or DNA methylation in vertebrates has been implicated in the regulation of expression of some genes in eukaryotes, but a large number of genes lack these sequences. On the other hand, several experimental and computational studies have shown that promoter sequences possess some special structural properties, such as low stability, less bendability, low nucleosome occupancy, and more curvature, which are prevalent across all organisms. These structural features may play role in transcription initiation and regulation of gene expression. We have studied the relationship between the structural features of promoter DNA, promoter directionality and gene expression variability in S. cerevisiae. This relationship has been analyzed for seven different measures of gene expression variability, along with two different regulatory effect measures. We find that a few of the variability measures of gene expression are linked to DNA structural properties, nucleosome occupancy, TATA-box presence, and bidirectionality of promoter regions. Interestingly, gene responsiveness is most intimately correlated with DNA structural features and promoter architecture.

Keystone food resources for honey bees in South Indian west coast during monsoon

The low level, denuded, laterite landscape of coastal Uttara Kannada has a rich diversity of monsoon herbs, including threatened and newly discovered ones. Our study reveals that honey bees congregate on the ephemeral herb community of Utricularias, Eriocaulons and Impatiens during their gregarious monsoon flowering period. Apis dorsata had highest visitations on Utricularias, Impatiens and Flacourtia indica, whereas Trigona preferred Eriocaulons. Laterite herb flora merits conservation efforts as a keystone food resource for the insect community, especially for honey bees.

BIOMASS GASIFICATION TO SUBSTITUTE FOSSIL FUEL IN FOOD INDUSTRY

Food industries like biscuit and confectionary use significant amount of fossil fuel for thermal energy. Biscuit manufacturing in India is carried out both by organized and unorganized sector. The ratio of organized to unorganized sector is 60 : 40 (1). The total biscuit manufacturing in the organized sector India in 2008 was about 1.7 million metric tons (1). Accounting for the unorganized sector in India, the total biscuit manufacturing would have been about 2.9 million metric tons/annum. A typical biscuit baking is carried in a long tunnel kiln with varying temperature in different zones. Generally diesel is used to provide the necessary heat energy for the baking purpose, with temperature ranging from 190 C in the drying zone to about 300 C in the baking area and has to maintain in the temperature range of +/- 5 C. Typical oil consumption is about 40 litres per ton of biscuit production. The paper discusses the experience in substituting about 120 lts per hour kiln for manufacturing about 70 tons of biscuit daily. The system configuration consists of a 500 kg/hr gasification system comprising of a reactor, multicyclone, water scrubbers, and two blowers for maintaining the constant gas pressure in the header before the burners. Cold producer gas is piped to the oven located about 200 meters away from the gasifier. Fuel used in the gasification system is coconut shells. All the control system existing on the diesel burner has been suitably adapted for producer gas operation to maintain the total flow, A/F control so as to maintain the temperature. A total of 7 burners are used in different zones. Over 17000 hour of operation has resulted in replacing over 1800 tons of diesel over the last 30 months. The system operates for over 6 days a week with average operational hours of 160. It has been found that on an average 3.5 kg of biomass has replaced one liter of diesel.