Hygienic behaviour in the honeybee (Apis mellifera) has been shown to be an effective control mechanism against brood diseases such as chalkbrood and AFB. Chalkbrood has proven to be problematic for the Australian honey industry since it was identified here in 1993. Hygienic behaviour is a much studied trait. Rothenbuhler investigated the genetic basis of hygienic behaviour, proposing a two-gene model to explain the uncapping and removal of dead brood. His elegant experiment remains the textbook example of a behavioural genetic study. Although this model has been challenged, it is still generally agreed that a small number of unlinked genes produce a large effect on hygienic behaviour, that hygienic alleles are recessive and are inherited in a Mendelian manner. Experimental backcross colonies were produced from an inbred hygienic line and an inbred non-hygienic line, both provided by Dr. Marla Spivak, University of Minnesota. These backcross colonies were assessed for hygienic behaviour using a standard assay. Statistical analyses of the field data indicated that the genetic basis of the trait was more complex than either the simple Mendelian and widely accepted two-gene or three-gene models that have been proposed previously. Molecular techniques, linkage mapping and QTL analysis then were employed to determine how many loci directly influence hygienic behaviour and the relative level of influence and location of each locus within the genome of A. mellifera. Full multipoint linkage analysis by Mapmaker v3.0 software produced a new genetic map of the honeybee comprised of 358 marker loci ordered over 25 linkage groups spanning a total distance of 3406.2 cM. The average distance between each marker was 9.5 cM. QTL analysis of the experimental data identified seven putative genetic markers associated with hygienic behaviour. QTLs located on linkage groups 2, 4, 6 and 22 were detected for both overall hygienic behaviour and uncapping behaviour only. Individually, each QTL is of relatively small effect with each explaining only 9% � 15% of the variance in hygienic levels observed. Collectively, the putative QTLs identified here explain 79.4% of the observed variance in the expression of hygienic behaviour. These results indicate that there are many genes of low to moderate effect rather than few genes of large effect involved in this complex behavioural trait. This is typical of inherited quantitative traits which do not exhibit Mendelian phenotypic ratios. DNA extracted from the brood samples taken during testing of commercial stock, and from individual bees identified as either highly hygienic or non-hygienic in a reciprocal backcross experiment, were screened with the candidate markers associated with putative QTLs to test their diagnostic power. Unfortunately, none have produced reliably diagnostic DNA profiles. As we have now shown that hygienic behaviour is a polygenic, quantitative trait, simple diagnostic markers for Rothenbuhler's 'uncapping' and 'removal' genes are unlikely to be achieved. Our results show that the most likely way to improve disease resistance in Australian stock is via traditional methods of recurrent selection. The project was responsible for the importation of new genetic material into Australia from the United States. This hygienic stock has been well received by industry, has been widely disseminated, and incorporated into local breeding programs. We hope that it has lead to a general improvement in the level of disease resistance in Australian commercial bees.

Hygienic behaviour in the honeybee (Apis mellifera) has been shown to be an effective control mechanism against brood diseases such as chalkbrood and AFB. Chalkbrood has proven to be problematic for the Australian honey industry since it was identified here in 1993. Hygienic behaviour is a much studied trait. Rothenbuhler investigated the genetic basis of hygienic behaviour, proposing a two-gene model to explain the uncapping and removal of dead brood. His elegant experiment remains the textbook example of a behavioural genetic study. Although this model has been challenged, it is still generally agreed that a small number of unlinked genes produce a large effect on hygienic behaviour, that hygienic alleles are recessive and are inherited in a Mendelian manner. Experimental backcross colonies were produced from an inbred hygienic line and an inbred non-hygienic line, both provided by Dr. Marla Spivak, University of Minnesota. These backcross colonies were assessed for hygienic behaviour using a standard assay. Statistical analyses of the field data indicated that the genetic basis of the trait was more complex than either the simple Mendelian and widely accepted two-gene or three-gene models that have been proposed previously. Molecular techniques, linkage mapping and QTL analysis then were employed to determine how many loci directly influence hygienic behaviour and the relative level of influence and location of each locus within the genome of A. mellifera. Full multipoint linkage analysis by Mapmaker v3.0 software produced a new genetic map of the honeybee comprised of 358 marker loci ordered over 25 linkage groups spanning a total distance of 3406.2 cM. The average distance between each marker was 9.5 cM. QTL analysis of the experimental data identified seven putative genetic markers associated with hygienic behaviour. QTLs located on linkage groups 2, 4, 6 and 22 were detected for both overall hygienic behaviour and uncapping behaviour only. Individually, each QTL is of relatively small effect with each explaining only 9% � 15% of the variance in hygienic levels observed. Collectively, the putative QTLs identified here explain 79.4% of the observed variance in the expression of hygienic behaviour. These results indicate that there are many genes of low to moderate effect rather than few genes of large effect involved in this complex behavioural trait. This is typical of inherited quantitative traits which do not exhibit Mendelian phenotypic ratios. DNA extracted from the brood samples taken during testing of commercial stock, and from individual bees identified as either highly hygienic or non-hygienic in a reciprocal backcross experiment, were screened with the candidate markers associated with putative QTLs to test their diagnostic power. Unfortunately, none have produced reliably diagnostic DNA profiles. As we have now shown that hygienic behaviour is a polygenic, quantitative trait, simple diagnostic markers for Rothenbuhler's 'uncapping' and 'removal' genes are unlikely to be achieved. Our results show that the most likely way to improve disease resistance in Australian stock is via traditional methods of recurrent selection. The project was responsible for the importation of new genetic material into Australia from the United States. This hygienic stock has been well received by industry, has been widely disseminated, and incorporated into local breeding programs. We hope that it has lead to a general improvement in the level of disease resistance in Australian commercial bees.

Orientador: Luiz Augusto do Amaral / Banca: Luiz Francisco Zafalon / Banca: Maria da Glória Buzinaro / Resumo: Nos últimos anos, o segmento de alimentos para animais de estimação no Brasil apresentou um expressivo crescimento no volume de vendas. O mercado brasileiro de rações para cães apresenta os maiores índices de crescimento mundial. Com os objetivos de verificar a qualidade higiênico-sanitária e a influência da venda a granel foram analisadas 15 marcas de rações para cães, em duplicata, oriundas de embalagens fechadas e da comercialização a granel. As amostras foram obtidas no comércio varejista dos Municípios de Jaboticabal e Ribeirão Preto/SP. Foram realizadas as determinações dos números mais prováveis de coliformes totais e termotolerantes, as contagens de bolores e leveduras e microrganismos mesófilos e a pesquisa de bactérias do gênero Salmonella. Os resultados obtidos evidenciaram que não houve diferença significativa nas contagens de bolores e leveduras e microrganismos mesófilos entre as amostras comercializadas em embalagens fechadas e a granel. Entretanto, nas amostras de rações comercializadas em embalagens fechadas foram verificadas maiores porcentagens de amostras contaminadas por bolores e leveduras e maior presença por indicadores de contaminação fecal. Não foram isoladas bactérias do gênero Salmonella nas amostras analisadas. Sugere-se que na comercialização a granel a ração seja embalada, para com isso preservar a qualidade microbiológica do produto. / Abstract: In the past years, pet food segment in Brazil has been experiencing a marked increase in sales' volume. The Brazilian dog food market has the world's highest growth rate. This study is aimed to verify the influence of in bulk sales and the hygienic-sanitary quality of dog food. Fifteen brands of dog food obtained from packages and from in bulk marketed were analyzed in duplicate. The samples were collected from retailers of Jaboticabal y Ribeirão Preto Municipality/SP. The most probable number of total coliforms and heat-resistant ones, the counts of yeasts, molds and mesophils, and Salmonella investigation were performed. Results for counts of yeasts, molds and mesophils showed no statistical significance between packed and in bulk food. However, it was verified that samples of in bulk food had greater percentage of molds, yeasts and fecal indicators contaminations. No bacteria of the genus Salmonella was found in analyzed samples. This study suggests that in bulk marketing should pack dog food in order to preserve its microbiological quality. / Mestre

No description available.

Thesis (Masters Diploma in Technology (Public Health)) -- Cape Technikon, Cape Town, 1992 / In order to evaluate a health education programme for food handlers at a meat plant, a bakery/confectionery and a catering premises, changes in hygiene were assessed by the bacteriological analysis of swabs for hygiene indicator organisms from food contact surfaces. In this evaluation three phases were established on the basis of bacteriological assessment prior to, during and after the education programme. The first phase involved the establishment of a base line for hygiene indicator organisms prior to the education programme by taking 5 sets of bacteriological swabs over a two month period at each of the three premises, each swab set consisting of 14 swabs of food contact surfaces making a total of 210 swabs. During this time the food hygiene educational needs of the employees were assessed and on this basis a set of three video taped presentations were produced relating respectively to personal hygiene, environmental hygiene and food handling practices. The second phase consisted of the implementation of a health education programme involving consecutive tutorial sessions at one month intervals during which the video taped programme was presented. At this stage a further 5 sets of bacteriological swabs was taken at each of the premises. The third phase involved the assessment of hygiene shortly after completion of the education programme by taking a final 5 sets of bacteriological swabs of food contact surfaces at each of the premises over a further two month period. Statistically significant reductions in a number of the indicator organisms were observed during the course of the study.

<p>Hair care is a hygienic treatment and is supervised by the Local Environment and Public Health Committee in the municipality. According to the Swedish Environmental Code, hairdressers as all practitioners are required to take measurements to protect the environment and public health. In hygienic treatments hazards may arise from inadequate hygiene practice which spread infection. Hazards may also arise from the use of hair care products such as permanent wave solutions, bleaches and hair dyes. Some hair dye components are known to cause contact allergy, mostly in hair dressers who are exposed professionally but also in some cases in consumers. Bleaches increase the risk of occupational asthma in hairdressers. Some studies have shown an increased risk of cancer in hairdressers and possibly also in consumers. The use of cosmetic and hygienic products also affects the environment. Some components, e.g. surfactants, are hazardous to aquatic organisms, even though the contribution from hair care products is relatively small. Some hairdressers perform ear piercing. All activities that penetrate the skin involve a risk of infection. There is also a risk of developing a nickel allergy if the earrings are not nickel free. In Sweden, due to recently changed legislation, hairdressers no longer need to notify the Local Environment and Public Health Committee before starting a practice. The changes also mean that the rules about documentation of the measurements practitioners need to take to protect public health are less clear. The changes have made the supervision of hairdressers harder for the Local Environment and Public Health Committee.</p>

Hair care is a hygienic treatment and is supervised by the Local Environment and Public Health Committee in the municipality. According to the Swedish Environmental Code, hairdressers as all practitioners are required to take measurements to protect the environment and public health. In hygienic treatments hazards may arise from inadequate hygiene practice which spread infection. Hazards may also arise from the use of hair care products such as permanent wave solutions, bleaches and hair dyes. Some hair dye components are known to cause contact allergy, mostly in hair dressers who are exposed professionally but also in some cases in consumers. Bleaches increase the risk of occupational asthma in hairdressers. Some studies have shown an increased risk of cancer in hairdressers and possibly also in consumers. The use of cosmetic and hygienic products also affects the environment. Some components, e.g. surfactants, are hazardous to aquatic organisms, even though the contribution from hair care products is relatively small. Some hairdressers perform ear piercing. All activities that penetrate the skin involve a risk of infection. There is also a risk of developing a nickel allergy if the earrings are not nickel free. In Sweden, due to recently changed legislation, hairdressers no longer need to notify the Local Environment and Public Health Committee before starting a practice. The changes also mean that the rules about documentation of the measurements practitioners need to take to protect public health are less clear. The changes have made the supervision of hairdressers harder for the Local Environment and Public Health Committee.

RESUMO As abelhas africanizadas (Apis mellifera L.) apresentam um comportamento higiênico mais intenso comparado a outras subespécies de abelhas europeias. Embora o comportamento higiênico das abelhas já seja bem conhecido, ainda existem estudos a serem feitos em torno desse complexo comportamento. Assim, no presente trabalho pretendeu-se obter subsídios para uma melhor compreensão desse comportamento em relação ao comportamento de forrageamento e ao desenvolvimento interno das colônias, através da comparação do desempenho entre colônias de linhagens higiênicas e não higiênicas de abelhas africanizadas (Apis mellifera L.). Portanto, quarenta e uma colônias de abelhas Africanizadas Apis mellifera L. foram testadas quanto ao comportamento higiênico (CH). O presente trabalho foi desenvolvido no Laboratório Apilab do Departamento de Genética da FMRP-USP. Foram constituídos dois grupos de colônias: um grupo de 3 colônias higiênicas (H) com CH igual ou superior a 90% e 3 colônias não higiênicas (NH) com valor igual ou inferior a 55%, com o objetivo de se estudar, mediante monitoramento mensal durante 13 meses (julho de 2011 a julho de 2012), as variáveis relacionadas ao desenvolvimento interno das colônias (atividade de postura, área de cria aberta e de cria operculada), atividades forrageiras (área de pólen, área de néctar aberto e de néctar operculado) e ganho de peso. Para o ganho de peso foram utilizadas balanças eletrônicas adaptadas. Os mapeamentos dos dados climáticos foram registrados por um período na Estação Climatológica do Apilab na USP, porém devido a um acidente com queda de energia a fonte foi queimada, não sendo possível o uso programado dos dados climáticos para estudos de correlação com as variáveis das colônias. Os dados das variáveis internas da colônia foram obtidos utilizando-se de um suporte de madeira com tela de arame dividindo a área total em 36 quadrantes idênticos dentro do qual se colocava o quadro da colmeia para se estimar as áreas respectivas em % (néctar, pólen, crias, oviposição etc.). Os dados foram transformados em arco-seno para aplicação dos testes estatísticos. As comparações estatísticas foram realizadas usando-se o teste t-Student e análises de correlação pelo método de Spearman, (Software Statistica 8). Como principais resultados obtivemos os seguintes: as colônias H tiveram melhor desempenho que as NH quanto as atividades de coleta de pólen (P = <0,001), área de cria aberta (P = <0,001), área de cria operculada (P = 0,050) e oviposição das rainhas (P = 0,015). As colônias H apresentaram maior taxa de remoção de crias doentes e mortas que as NH. As abelhas das colônias H são melhores coletoras de pólen que as NH. Não houve diferença entre as linhagens quanto ao ganho de peso. Encontramos correlação positiva significante nas colônias (H e NH) entre áreas de pólen com as áreas com cria aberta H (r = 0,599; P = 0,029), NH (r = 0,791; P = 0,000) e entre as áreas de pólen com cria operculada H (r = 0,659; P = 0,013), NH (r = 0,731; P = 0,004), confirmando que o feromônio das larvas estimula a coleta de pólen. Houve também correlação positiva significante nas colônias H entre área de néctar operculado e cria operculada (r = 0,714; P = 0,005), e néctar operculado e pólen (r = 0,659; P = 0,013). Concluiu-se que o CH pode também ser utilizado como uma característica para critério de seleção para produção de pólen, sendo o CH considerado como uma das melhores alternativas para os programas de melhoramento de abelhas. / The africanized bees (Apis mellifera L.) present a more intensive hygienic behavior in comparison with another European subspecies bees. Although the hygienic behavior of these bees is already very known, there are studies being conducted on this complex behavior. Then, the present study aimed to obtain data to comprehend better the hygienic behavior in relation to the forager behavior and to the internal development of colonies through the comparison of development between colonies of A. mellifera bees from lineage hygienic and not hygienic. Thus, forty-one colonies of Africanized honey bee (Apis mellifera L.) were tested for hygienic behavior. This work was developed in the Apilab of the Department of Genetics, FMRP-USP in Ribeirão Preto-SP. There were two groups of colonies: a group of 3 hygienic colonies (H) ( H test => 90% ) and 3 non-hygienic colonies (NH) ( H test =< 55%) , with the objective of studying, through monitoring monthly from July/ 2011 to July/ 2012, variables related to the internal development of the colonies (oviposition area, open brood area and capped brood area) foraging activities (pollen area, open nectar area, capped nectar area) and weight gain. For weight gain determination adapted electronic scales were used. Mappings of climatic data were recorded for a period at the Apilab-USP, but due to an accident the Climatological Station was damaged, not being possible the correlation studies. Data of internal variables of the colonies were obtained using a wooden support mesh wire dividing the total area under 36 identical quadrants within which is placed the frame of the hive to estimate the respective areas in % (nectar, pollen, brood, eggs etc.). Data were transformed to arcsine in statistical tests. Statistical comparisons were performed using the Student t test and correlation analysis by the method of Spearman (Software Statistica 8). As main results we achieved the following: H colonies outperformed the NH in the following variables: pollen area (P = <0.001), open brood area (P = <0.001), capped brood area (P = 0.050) and oviposition (P = 0.015). Hygienic colonies (H) showed higher removal rate of sick and dead brood than Non hygienic colonies (NH). The Africanized Honey Bees of the Hygienic colonies ( H ) are better pollen-collecting than the Honey Bees of the Non-hygienic colonies (NH). There was no difference between strains regarding weight gain. Significant positive correlation was found in both groups of colonies (H and NH) between area of pollen with open brood H (r = 0.599; P = 0.029), NH (r = 0.791; P = 0.000) and between areas of pollen with capped brood H (r = 0.659; P = 0.013), NH (r = 0.731; P = 0.004), confirming that the larval pheromone stimulates pollen collection. There were also significant positive correlation in the Hygienic colonies (H) between area of capped brood and capped nectar area (r = 0.714; P = 0.005) as well as between pollen area and capped nectar area (r = 0.659; P = 0.013). It was also concluded that the Hygienic Behavior of the Honey Bees can also be used as a feature selection for pollen production. The Hygienic Behavior feature is being considered today as one of the best alternatives for Honey Bee breeding programs.

RESUMO As abelhas africanizadas (Apis mellifera L.) apresentam um comportamento higiênico mais intenso comparado a outras subespécies de abelhas europeias. Embora o comportamento higiênico das abelhas já seja bem conhecido, ainda existem estudos a serem feitos em torno desse complexo comportamento. Assim, no presente trabalho pretendeu-se obter subsídios para uma melhor compreensão desse comportamento em relação ao comportamento de forrageamento e ao desenvolvimento interno das colônias, através da comparação do desempenho entre colônias de linhagens higiênicas e não higiênicas de abelhas africanizadas (Apis mellifera L.). Portanto, quarenta e uma colônias de abelhas Africanizadas Apis mellifera L. foram testadas quanto ao comportamento higiênico (CH). O presente trabalho foi desenvolvido no Laboratório Apilab do Departamento de Genética da FMRP-USP. Foram constituídos dois grupos de colônias: um grupo de 3 colônias higiênicas (H) com CH igual ou superior a 90% e 3 colônias não higiênicas (NH) com valor igual ou inferior a 55%, com o objetivo de se estudar, mediante monitoramento mensal durante 13 meses (julho de 2011 a julho de 2012), as variáveis relacionadas ao desenvolvimento interno das colônias (atividade de postura, área de cria aberta e de cria operculada), atividades forrageiras (área de pólen, área de néctar aberto e de néctar operculado) e ganho de peso. Para o ganho de peso foram utilizadas balanças eletrônicas adaptadas. Os mapeamentos dos dados climáticos foram registrados por um período na Estação Climatológica do Apilab na USP, porém devido a um acidente com queda de energia a fonte foi queimada, não sendo possível o uso programado dos dados climáticos para estudos de correlação com as variáveis das colônias. Os dados das variáveis internas da colônia foram obtidos utilizando-se de um suporte de madeira com tela de arame dividindo a área total em 36 quadrantes idênticos dentro do qual se colocava o quadro da colmeia para se estimar as áreas respectivas em % (néctar, pólen, crias, oviposição etc.). Os dados foram transformados em arco-seno para aplicação dos testes estatísticos. As comparações estatísticas foram realizadas usando-se o teste t-Student e análises de correlação pelo método de Spearman, (Software Statistica 8). Como principais resultados obtivemos os seguintes: as colônias H tiveram melhor desempenho que as NH quanto as atividades de coleta de pólen (P = <0,001), área de cria aberta (P = <0,001), área de cria operculada (P = 0,050) e oviposição das rainhas (P = 0,015). As colônias H apresentaram maior taxa de remoção de crias doentes e mortas que as NH. As abelhas das colônias H são melhores coletoras de pólen que as NH. Não houve diferença entre as linhagens quanto ao ganho de peso. Encontramos correlação positiva significante nas colônias (H e NH) entre áreas de pólen com as áreas com cria aberta H (r = 0,599; P = 0,029), NH (r = 0,791; P = 0,000) e entre as áreas de pólen com cria operculada H (r = 0,659; P = 0,013), NH (r = 0,731; P = 0,004), confirmando que o feromônio das larvas estimula a coleta de pólen. Houve também correlação positiva significante nas colônias H entre área de néctar operculado e cria operculada (r = 0,714; P = 0,005), e néctar operculado e pólen (r = 0,659; P = 0,013). Concluiu-se que o CH pode também ser utilizado como uma característica para critério de seleção para produção de pólen, sendo o CH considerado como uma das melhores alternativas para os programas de melhoramento de abelhas. / The africanized bees (Apis mellifera L.) present a more intensive hygienic behavior in comparison with another European subspecies bees. Although the hygienic behavior of these bees is already very known, there are studies being conducted on this complex behavior. Then, the present study aimed to obtain data to comprehend better the hygienic behavior in relation to the forager behavior and to the internal development of colonies through the comparison of development between colonies of A. mellifera bees from lineage hygienic and not hygienic. Thus, forty-one colonies of Africanized honey bee (Apis mellifera L.) were tested for hygienic behavior. This work was developed in the Apilab of the Department of Genetics, FMRP-USP in Ribeirão Preto-SP. There were two groups of colonies: a group of 3 hygienic colonies (H) ( H test => 90% ) and 3 non-hygienic colonies (NH) ( H test =< 55%) , with the objective of studying, through monitoring monthly from July/ 2011 to July/ 2012, variables related to the internal development of the colonies (oviposition area, open brood area and capped brood area) foraging activities (pollen area, open nectar area, capped nectar area) and weight gain. For weight gain determination adapted electronic scales were used. Mappings of climatic data were recorded for a period at the Apilab-USP, but due to an accident the Climatological Station was damaged, not being possible the correlation studies. Data of internal variables of the colonies were obtained using a wooden support mesh wire dividing the total area under 36 identical quadrants within which is placed the frame of the hive to estimate the respective areas in % (nectar, pollen, brood, eggs etc.). Data were transformed to arcsine in statistical tests. Statistical comparisons were performed using the Student t test and correlation analysis by the method of Spearman (Software Statistica 8). As main results we achieved the following: H colonies outperformed the NH in the following variables: pollen area (P = <0.001), open brood area (P = <0.001), capped brood area (P = 0.050) and oviposition (P = 0.015). Hygienic colonies (H) showed higher removal rate of sick and dead brood than Non hygienic colonies (NH). The Africanized Honey Bees of the Hygienic colonies ( H ) are better pollen-collecting than the Honey Bees of the Non-hygienic colonies (NH). There was no difference between strains regarding weight gain. Significant positive correlation was found in both groups of colonies (H and NH) between area of pollen with open brood H (r = 0.599; P = 0.029), NH (r = 0.791; P = 0.000) and between areas of pollen with capped brood H (r = 0.659; P = 0.013), NH (r = 0.731; P = 0.004), confirming that the larval pheromone stimulates pollen collection. There were also significant positive correlation in the Hygienic colonies (H) between area of capped brood and capped nectar area (r = 0.714; P = 0.005) as well as between pollen area and capped nectar area (r = 0.659; P = 0.013). It was also concluded that the Hygienic Behavior of the Honey Bees can also be used as a feature selection for pollen production. The Hygienic Behavior feature is being considered today as one of the best alternatives for Honey Bee breeding programs.

<p>The main project Dry preservation of food waste from households includes a new technique concerning drying and storage of dried biowaste as well as a study of the sorting of household waste and further usage of the dried biowaste. A question asked in the project is, can the dried biowaste be used as a soil amendment? If organic waste is used as a soil amendment, precaution concerning hygienic safety risks has to be accounted for. The objective of this M. Sc. Thesis Work was to first find a suitable method to attain hygienic safety through a literature study, to test and evaluate the method and to test if a method changes the composition or structure of the material. An existing recipe for food waste was developed and used throughout the work.</p><p>Heating of the dried biowaste is probably the most suitable method to reach and attain a hygienically safe product. Three time-temperature proportions were tested, 55, 70 and 80°C. The results show that a raise in temperature lead to a change in the composition of the dried biowaste, most distinctively for the highest temperature. Nitrogen losses of 21% of the total nitrogen content were noticed. A composting experiment showed that the biowaste heated to the highest temperature was decomposed to a higher degree. It does not, however, seem like a heating process will decrease the possibility to use dried biowaste as a soil improvement.</p> / <p>Projektet Torrkonservering av matavfall från hushåll innefattar en ny teknik för torkning och lagring av bioavfall, hushållens sortering och vidare användning av det torkade materialet. För att sluta det naturliga kretsloppet utreds om det torkade bioavfallet kan användas som ett jordförbättringsmedel. När organiskt avfall ska användas som ett jordförbättringsmedel ställs krav på hygienisk säkerhet. Examensarbetets syfte var att, genom litteraturstudier, utreda lämplig hygieniseringsmetod att vidare testa praktiskt, samt att testa om en hygieniseringsprocess medför några förändringar på det torkade bioavfallets materialegenskaper. Ett befintligt standardrecept på matavfall vidareutvecklades och användes.</p><p>Resultaten tyder på att upphettning av det torkade bioavfallet förmodligen är den mest lämpliga hygieniseringsmetoden. Tre olika tid- temperaturförhållanden testades, 55, 70 och 80°C. Laborationer och analyser tyder på att det torkade bioavfallet genomgår en viss förändring av den kemiska sammansättningen vid upphettning, vilket är tydligast för den högsta hygieniseringstemperaturen. Bland annat sker kväveförluster på upp till 21 % av totalkvävet. Komposteringstester visar på att nedbrytningsgraden är högst för bioavfall som hygieniserats vid den högsta temperaturen. Det verkar inte som om hygienisering, genom upphettning, minskar möjligheten att använda torkat bioavfall som ett jordförbättringsmedel.</p>