Diversity, local uses and availability of medicinal plants and wild yams in the Mahafaly region of south-western Madagascar

Short summary: This study was undertaken to assess the diversity of plant resources utilized by the local population in south-western Madagascar, the social, ecological and biophysical conditions that drive their uses and availability, and possible alternative strategies for their sustainable use in the region. The study region, ‘Mahafaly region’, located in south-western Madagascar, is one of the country’s most economically, educationally and climatically disadvantaged regions. With an arid steppe climate, the agricultural production is limited by low water availability and a low level of soil nutrients and soil organic carbon. The region comprises the recently extended Tsimanampetsotsa National Park, with numerous sacred and communities forests, which are threatened by slash and burn agriculture and overexploitation of forests resources. The present study analyzed the availability of wild yams and medicinal plants, and their importance for the livelihood of the local population in this region. An ethnobotanical survey was conducted recording the diversity, local knowledge and use of wild yams and medicinal plants utilized by the local communities in five villages in the Mahafaly region. 250 households were randomly selected followed by semi-structured interviews on the socio-economic characteristics of the households. Data allowed us to characterize sociocultural and socioeconomic factors that determine the local use of wild yams and medicinal plants, and to identify their role in the livelihoods of local people. Species-environment relationships and the current spatial distribution of the wild yams were investigated and predicted using ordination methods and a niche based habitat modelling approach. Species response curves along edaphic gradients allowed us to understand the species requirements on habitat conditions. We thus investigated various alternative methods to enhance the wild yam regeneration for their local conservation and their sustainable use in the Mahafaly region. Altogether, six species of wild yams and a total of 214 medicinal plants species from 68 families and 163 genera were identified in the study region. Results of the cluster and discriminant analysis indicated a clear pattern on resource, resulted in two groups of household and characterized by differences in livestock numbers, off-farm activities, agricultural land and harvests. A generalized linear model highlighted that economic factors significantly affect the collection intensity of wild yams, while the use of medicinal plants depends to a higher degree on socio-cultural factors. The gradient analysis on the distribution of the wild yam species revealed a clear pattern for species habitats. Species models based on NPMR (Nonparametric Multiplicative Regression analysis) indicated the importance of vegetation structure, human interventions, and soil characteristics to determine wild yam species distribution. The prediction of the current availability of wild yam resources showed that abundant wild yam resources are scarce and face high harvest intensity. Experiments on yams cultivation revealed that germination of seeds was enhanced by using pre-germination treatments before planting, vegetative regeneration performed better with the upper part of the tubers (corms) rather than the sets of tubers. In-situ regeneration was possible for the upper parts of the wild tubers but the success depended significantly on the type of soil. The use of manure (10-20 t ha¹) increased the yield of the D. alata and D. alatipes by 40%. We thus suggest the promotion of other cultivated varieties of D. alata found regions neighbouring as the Mahafaly Plateau.

Shifting cultivation and forest resources in Nagaland, N.-E. India

Die vorliegende Studie befasst sich mit der Ressourcennachhaltigkeit der traditionellen, auf Wanderfeldbau beruhenden Subsistenzwirtschaft in zwei Dörfern (Hongphoy und Minyakshu) in Nagaland im Nordosten Indiens. Hierbei werden die Cerealien Produktion, der Feuerholz Konsum und auch die Folgen der intensivierten Bewirtschaftung (Forstdegradation und Bodenverarmung) im Hinblick auf das Bevölkerungswachstum diskutiert. Während das traditionelle System des Wanderfeldbaus (Jhum) seit Jahrzehnten die Bedürfnisse der ehemals kopfjagenden Stämme Nagalands erfüllte, ergab unsere Studie durch Interviews und Feldaufnahmen in 2004 und 2005, dass die steigende Nachfrage einer wachsenden Bevölkerung nach Cerealien und Feuerholz als wichtigste Ressourcen der Subsistenzwirtschaft zu einer verkürzten Brachezeit und letztlich der Degradation von Naturressourcen geführt hat: Pro Hektar Ernten sind reduziert und der Zuwachs der Holzvorräte auf den Feldern kann durch die verkürzten Bracheperioden nicht mehr die Feuerholz Nachfrage decken. Eine Nahrungsmittelknappheit wurde durch die Gegenüberstellung des Energiebedarfs einer Person und die jährlichen pro-Kopf Erntemengen und unter Berücksichtigung des Zukaufs von Reis reflektiert: In Hongphoy ergab dies ein Defizit auf Dorfebene von 130 Tonnen Reis, in Minyakshu von 480 Tonnen, die nicht durch Ernten gedeckt werden konnten. Diese Nahrungsmittelknappheit erweist sich vor allem vor dem Hintergrund eines Bevölkerungswachstums von 6.7% und marginalen Einkünften als problematisch. Für fünf verschiedene Waldformationen (zwei Brachewälder, zwei Dorfwälder und ein Naturwald) wurden die unterschiedliche Artenzusammensetzung (Diversität) und Bestandesvolumina durch Forstinventuren beschrieben. Der dem Bestandesvolumen der Brachewälder gegenübergestellte pro-Kopf Feuerholz Bedarf ergab ein jährliches Defizit von 1,81m³ in Hongphoy und 0.05m³ in Minyakshu. Der Unterschied dieses Defizits zwischen beiden Dörfern wurde in einer abweichenden Bestandesstruktur (Dominanz der N2 fixierenden Baumart Alnus nepalensis in den Brachewäldern Minyakshus) begründet. Über den erhobenen Feuerholzbedarf wurde ein theoretischer pro-Kopf Flächenbedarf an Brachewald errechnet, der nötig wäre um den gesamten Feuerholz Bedarf innerhalb des Wanderfeldbau Systems zu decken. Das daraus resultierende Defizit wurde mit den Feuerholzvolumina der Dorfwälder und des verbliebenen Naturwalds gegenüber gestellt. Hieraus ergibt sich die Bedeutung der Feuerholzernte und des Wanderfeldbau als Ursache für die fortschreitende Entwaldung und Forstdegradation in Nagaland. Mit Hilfe dieser Informationen und aktuellen Angaben zum Bevölkerungswachstum werden die Ergebnisse anhand einschlägiger Literatur diskutiert und letztendlich die Nachhaltigkeit und Tragfähigkeit des Wanderfeldbau Systems in dieser Region bestimmt. Mögliche Verbesserungsstrategien um der zunehmenden Ressourcendegradation zu begegnen, werden andiskutiert.

Local food security and principle of organic farming (from farm to fork) in context of food culture in Indonesia: Minangkabau's case study

The basic idea behind improving local food security consists of two paths; first, accessibility (price, stock) and second, availability (quantity and biodiversity); both are perquisites to the provision of nutrients and a continuous food supply with locally available resources. The objectives of this thesis are to investigate if indigenous knowledge still plays an important role in traditional farming in the Minangkabau`s culture, thus supporting local food security. If the indigenous knowledge still plays a role in food culture in the Minangkabau`s culture which is linked to the matrilineal role and leads to a sound nutrition. Further, it should be tested if marantau influences traditional farming and food culture in Minangkabau`s, and if the local government plays a role in changing of traditional farming systems and food culture. Furthermore this thesis wants to prove if education and gender are playing a role in changing traditional farming system and food culture, and if the mass media affects traditional farming systems and food culture for the Minangkabau. The study was completed at four locations in West Sumatera; Nagari Ulakan (NU) (coastal area), Nagari Aia Batumbuak (NAB) (hilly area), Nagari Padang Laweh Malalo (NPLM) (lake area), Nagari Pandai Sikek (NPS) (hilly area). The rainfall ranged from 1400- 4800 mm annually with fertile soils. Data was collected by using PRA (Participatory Rural Appraisal) to investigate indigenous knowledge (IK) and its interactions, which is also combining with in depth-interview, life history, a survey using semi-structured-questionnaire, pictures, mapping, and expert interview. The data was collected from June - September 2009 and June 2010. The materials are; map of area, list of names, questionnaires, voices recorder, note book, and digital camera. The sampling method was snowball sampling which resulted in the qualitative and quantitative data taken. For qualitative data, ethnography and life history was used. For quantitative, a statistical survey with a semi-structured questionnaire was used. 50 respondents per each site participated voluntarily. Data was analyzed by performing MAXQDA 10, and F4 audio analysis software (created and developed by Philip-University Marburg). The data is clustered based on causality. The results show that; the role of IK on TFS (traditional farming system) shown on NPLM which has higher food crop biodiversity in comparison to the other three places even though it has relatively similar temperature and rainfall. This high food crop biodiversity is due to the awareness of local people who realized that they lived in unfavourable climate and topography; therefore they are more prepared for any changes that may occur. Carbohydrate intake is 100 % through rice even though they are growing different staple crops. Whereas most of the people said in the interviews that not eating rice is like not really eating for them. In addition to that, mothers still play an important role in kitchen activities. But when the agriculture income is low, mothers have to decide whether to change the meals or to feel insecure about their food supply. Marantau yields positive impact through the remittances it provides to invest on the farm. On the other hand, it results in fewer workers for agriculture, and therefore a negative impact on the transfer of IK. The investigation showed that the local government has a PTS (Padi Tanam Sabatang) programme which still does not guarantee that the farmers are getting sufficient revenue from their land. The low agricultural income leads to situation of potential food insecurity. It is evident that education is equal among men and women, but in some cases women tend to leave school earlier because of arranged marriages or the distances of school from their homes. Men predominantly work in agriculture and fishing, while women work in the kitchen. In NAB, even though women work on farmland they earn less then men. Weaving (NPS) and kitchen activity is recognized as women’s work, which also supports the household income. Mass media is not yielding any changes in TFS and food culture in these days. The traditional farming system has changed because of intensive agricultural extension which has introduced new methods of agriculture for the last three decades (since the 1980’s). There is no evidence that they want to change any of their food habits because of the mass media despite the lapau activity which allows them to get more food choices, instead preparing traditional meal at home. The recommendations of this thesis are: 1) The empowerment of farmers. It is regarding the self sufficient supply of manure, cooperative seed, and sustainable farm management. Farmers should know – where are they in their state of knowledge – so they can use their local wisdom and still collaborate with new sources of knowledge. Farmers should learn the prognosis of supply and demand next prior to harvest. There is a need for farm management guidelines; that can be adopted from both their local wisdom and modern knowledge. 2) Increase of non-agricultural income Increasing the non-agricultural income is strongly recommended. The remittances can be invested on non-agricultural jobs. 3) The empowerment of the mother. The mother plays an important role in farm to fork activities; the mother can be an initiator and promoter of cultivating spices in the backyard. Improvement of nutritional knowledge through information and informal public education can be done through arisan ibu-ibu and lapau activity. The challenges to apply these recommendations are: 1) The gap between institutions and organizations of local governments. There is more than one institution involved in food security policy. 2) Training and facilities for field extension agriculture (FEA) is needed because the rapid change of interaction between local government and farmer’s dependent on this agency.

Attitudes and behaviour towards food attributes and organic food – a triangular methodological investigation of occasional organic consumers

Organic food is increasingly available in the conventional food retail, where organic products are offered alongside with various other types of products and compete mainly with conventional and the so-called conventional-plus products. The latter are conventional products displaying particular quality attributes on the product packaging, such as ‘no artificial additives’, or ‘from animal welfare husbandry’. Often, these quality attributes also apply to organic products. Occasional organic consumers might prefer such conventional-plus alternatives that are perceived to be ‘between’ organic and conventional products. The overall objective of this PhD thesis was to provide information about the segment of occasional organic consumers. In particular, the thesis focussed on consumer perceptions and attitudes towards the quality of, and preferences for, organic, conventional and conventional-plus products in two countries: Germany and Switzerland. To achieve these objectives, qualitative and quantitative consumer research was combined in order to explore occasional organic consumers’ perceptions and attitudes as well as to observe their preferences and buying behaviour regarding different types of food products: organic, conventional and conventional-plus products. The qualitative research showed that, depending on single criteria, organic production was both positively as well as negatively assessed by consumers. Consumer perception of organic food was found to be highly selective and primarily focussed on the final stage of the particular production process. A major problem is that consumers are still mostly unfamiliar with factors associated with organic production, have a lack of confidence, and often confuse organic with conventional products. Besides this, consumer expectations of organic products are different from the expectations of conventional products. The quantitative research revealed that attitudes strongly determine consumers’ preferences for organic, conventional and conventional-plus products. Consumer attitudes tended to differ more between organic and conventional choices rather than conventional-plus and conventional choices. Furthermore, occasional organic consumers are heterogeneous in their preferences. They can be grouped into two segments: the consumers in one segment were less price sensitive and preferred organic products. The consumers in the other segment were more price sensitive and rather preferred conventional-plus or conventional products. To conclude, given the selective and subjective nature of consumer perception and the strong focus of consumer perception on the final stage of the food production process, specific additional values of organic farming should be communicated in clear and catchy messages. At the same time, these messages should be particularly focussed on the final stage of organic food production. The communication of specific added values in relation with organic products to improve the perceived price-performance-ratio is important since conventional-plus products represent an interesting alternative particularly for price sensitive occasional organic consumers. Besides this, it is important to strengthen affirmative consumer attitudes towards organic production. Therefore, policy support should emphasise on long-term communication campaigns and education programmes to increase the consumer awareness and knowledge of organic food and farming. Since consumers expect that organic food is regionally or at least domestically produced while they less accept organic imports, policy support of domestic and regional producers is a crucial measure to fill the current gap between the increasing consumer demand of organic food and the stagnation of the domestic and regional organic food supply.

Status and Potential of Smallholder Livestock Production Systems in Xishuangbanna, southern P.R. China

With Chinas rapid economic development during the last decades, the national demand for livestock products has quadrupled within the last 20 years. Most of that increase in demand has been answered by subsidized industrialized production systems, while million of smallholders, which still provide the larger share of livestock products in the country, have been neglected. Fostering those systems would help China to lower its strong urban migration streams, enhance the livelihood of poorer rural population and provide environmentally save livestock products which have a good chance to satisfy customers demand for ecological food. Despite their importance, China’s smallholder livestock keepers have not yet gained appropriate attention from governmental authorities and researchers. However, profound analysis of those systems is required so that adequate support can lead to a better resource utilization and productivity in the sector. To this aim, this pilot study analyzes smallholder livestock production systems in Xishuangbanna, located in southern China. The area is bordered by Lao and Myanmar and geographically counts as tropical region. Its climate is characterized by dry and temperate winters and hot summers with monsoon rains from May to October. While the regionis plain, at about 500 m asl above sea level in the south, outliers of the Himalaya mountains reach out into the north of Xishuangbanna, where the highest peak reaches 2400 m asl. Except of one larger city, Jinghong, Xishuangbanna mainly is covered by tropical rainforest, areas under agricultural cultivation and villages. The major income is generated through inner-Chinese tourism and agricultural production. Intensive rubber plantations are distinctive for the lowland plains while small-scaled traditional farms are scattered in the mountane regions. In order to determine the current state and possible future chances of smallholder livestock production in that region, this study analyzed the current status of the smallholder livestock sector in the Naban River National Nature Reserve (NRNNR), an area which is largely representative for the whole prefecture. It covers an area of about 50square kilometer and reaches from 470 up to 2400 m asl. About 5500 habitants of different ethnic origin are situated in 24 villages. All data have been collected between October 2007 and May 2010. Three major objectives have been addressed in the study: 1. Classifying existing pig production systems and exploring respective pathways for development 2. Quantifying the performance of pig breeding systemsto identify bottlenecks for production 3. Analyzing past and current buffalo utilization to determine the chances and opportunities of buffalo keeping in the future In order to classify the different pig production s ystems, a baseline survey (n=204, stratified cluster sampling) was carried out to gain data about livestock species, numbers, management practices, cultivated plant species and field sizes as well associo-economic characteristics. Sampling included two clusters at village level (altitude, ethnic affiliation), resulting in 13 clusters of which 13-17 farms were interviewed respectively. Categorical Principal Component Analysis (CatPCA) and a two-step clustering algorithm have been applied to identify determining farm characteristics and assort recorded households into classes of livestock production types. The variables keep_sow_yes/no, TLU_pig, TLU_buffalo, size_of_corn_fields, altitude_class, size_of_tea_plantationand size_of_rubber_fieldhave been found to be major determinants for the characterization of the recorded farms. All farms have extensive or semi-intensive livestock production, pigs and buffaloes are predominant livestock species while chicken and aquaculture are available but play subordinate roles for livelihoods. All pig raisers rely on a single local breed, which is known as Small Ear Pig (SMEP) in the region. Three major production systemshave been identified: Livestock-corn based LB; 41%), rubber based (RB; 39%) and pig based (PB;20%) systems. RB farms earn high income from rubber and fatten 1.9 ±1.80 pigs per household (HH), often using purchased pig feed at markets. PB farms own similar sized rubber plantations and raise 4.7 ±2.77 pigs per HH, with fodder mainly being cultivated and collected in theforest. LB farms grow corn, rice and tea and keep 4.6 ±3.32 pigs per HH, also fed with collected and cultivated fodder. Only 29% of all pigs were marketed (LB: 20%; RB: 42%; PB: 25%), average annual mortality was 4.0 ±4.52 pigs per farm (LB: 4.6 ±3.68; RB: 1.9 ±2.14; PB: 7.1 ±10.82). Pig feed mainly consists of banana pseudo stem, corn and rice hives and is prepared in batches about two to three times per week. Such fodder might be sufficient in energy content but lacks appropriate content of protein. Pigs therefore suffer from malnutrition, which becomes most critical in the time before harvest season around October. Farmers reported high occurrences of gastrointestinal parasites in carcasses and often pig stables were wet and filled with manure. Deficits in nutritional and hygienic management are major limits for development and should be the first issues addressed to improve productivity. SME pork was found to be known and referred by local customers in town and by richer lowland farmers. However, high prices and lacking availability of SME pork at local wet-markets were the reasons which limited purchase. If major management constraints are overcome, pig breeders (PB and LB farms) could increase the share of marketed pigs for town markets and provide fatteners to richer RB farmers. RB farmers are interested in fattening pigs for home consumption but do not show any motivation for commercial pig raising. To determine the productivity of input factors in pig production, eproductive performance, feed quality and quantity as well as weight development of pigs under current management were recorded. The data collection included a progeny history survey covering 184 sows and 437 farrows, bi-weekly weighing of 114 pigs during a 16-months time-span on 21 farms (10 LB and 11 PB) as well as the daily recording of feed quality and quantity given to a defined number of pigs on the same 21 farms. Feed samples of all recorded ingredients were analyzed for their respective nutrient content. Since no literature values on thedigestibility of banana pseudo stem – which is a major ingredient of traditional pig feed in NRNNR – were found, a cross-sectional digestibility trial with 2x4 pigs has been conducted on a station in the research area. With the aid of PRY Herd Life Model, all data have been utilized to determine thesystems’ current (Status Quo = SQ) output and the productivity of the input factor “feed” in terms of saleable life weight per kg DM feed intake and monetary value of output per kg DM feed intake.Two improvement scenarios were simulated, assuming 1) that farmers adopt a culling managementthat generates the highest output per unit input (Scenario 1; SC I) and 2) that through improved feeding, selected parameters of reproduction are improved by 30% (SC II). Daily weight gain averaged 55 ± 56 g per day between day 200 and 600. The average feed energy content of traditional feed mix was 14.92 MJ ME. Age at first farrowing averaged 14.5 ± 4.34 months, subsequent inter-farrowing interval was 11.4 ± 2.73 months. Littersize was 5.8 piglets and weaning age was 4.3 ± 0.99 months. 18% of piglets died before weaning. Simulating pig production at actualstatus, it has been show that monetary returns on inputs (ROI) is negative (1:0.67), but improved (1:1.2) when culling management was optimized so that highest output is gained per unit feed input. If in addition better feeding, controlled mating and better resale prices at fixed dates were simulated, ROI further increased to 1:2.45, 1:2.69, 1:2.7 and 1:3.15 for four respective grower groups. Those findings show the potential of pork production, if basic measures of improvement are applied. Futureexploration of the environment, including climate, market-season and culture is required before implementing the recommended measures to ensure a sustainable development of a more effective and resource conserving pork production in the future. The two studies have shown that the production of local SME pigs plays an important role in traditional farms in NRNNR but basic constraints are limiting their productivity. However, relatively easy approaches are sufficient for reaching a notable improvement. Also there is a demand for more SME pork on local markets and, if basic constraints have been overcome, pig farmers could turn into more commercial producers and provide pork to local markets. By that, environmentally safe meat can be offered to sensitive consumers while farmers increase their income and lower the risk of external shocks through a more diverse income generating strategy. Buffaloes have been found to be the second important livestock species on NRNNR farms. While they have been a core resource of mixed smallholderfarms in the past, the expansion of rubber tree plantations and agricultural mechanization are reasons for decreased swamp buffalo numbers today. The third study seeks to predict future utilization of buffaloes on different farm types in NRNNR by analyzing the dynamics of its buffalo population and land use changes over time and calculating labor which is required for keeping buffaloes in view of the traction power which can be utilized for field preparation. The use of buffaloes for field work and the recent development of the egional buffalo population were analyzed through interviews with 184 farmers in 2007/2008 and discussions with 62 buffalo keepers in 2009. While pig based farms (PB; n=37) have abandoned buffalo keeping, 11% of the rubber based farms (RB; n=71) and 100% of the livestock-corn based farms (LB; n=76) kept buffaloes in 2008. Herd size was 2.5 ±1.80 (n=84) buffaloes in early 2008 and 2.2 ±1.69 (n=62) in 2009. Field work on own land was the main reason forkeeping buffaloes (87.3%), but lending work buffaloes to neighbors (79.0%) was also important. Other purposes were transport of goods (16.1%), buffalo trade (11.3%) and meat consumption(6.4%). Buffalo care required 6.2 ±3.00 working hours daily, while annual working time of abuffalo was 294 ±216.6 hours. The area ploughed with buffaloes remained constant during the past 10 years despite an expansion of land cropped per farm. Further rapid replacement of buffaloes by tractors is expected in the near future. While the work economy is drastically improved by the use of tractors, buffaloes still can provide cheap work force and serve as buffer for economic shocks on poorer farms. Especially poor farms, which lack alternative assets that could quickly be liquidizedin times of urgent need for cash, should not abandon buffalo keeping. Livestock has been found to be a major part of small mixed farms in NRNNR. The general productivity was low in both analyzed species, buffaloes and pigs. Productivity of pigs can be improved through basic adjustments in feeding, reproductive and hygienic management, and with external support pig production could further be commercialized to provide pork and weaners to local markets and fattening farms. Buffalo production is relatively time intensive, and only will be of importance in the future to very poor farms and such farms that cultivate very small terraces on steep slopes. These should be encouraged to further keep buffaloes. With such measures, livestock production in NRNNR has good chances to stay competitive in the future.

Development of thermo-analytical prediction and classification models for food in thermal devices using a multi sensor system and artificial neural networks

Die thermische Verarbeitung von Lebensmitteln beeinflusst deren Qualität und ernährungsphysiologischen Eigenschaften. Im Haushalt ist die Überwachung der Temperatur innerhalb des Lebensmittels sehr schwierig. Zudem ist das Wissen über optimale Temperatur- und Zeitparameter für die verschiedenen Speisen oft unzureichend. Die optimale Steuerung der thermischen Zubereitung ist maßgeblich abhängig von der Art des Lebensmittels und der äußeren und inneren Temperatureinwirkung während des Garvorgangs. Das Ziel der Arbeiten war die Entwicklung eines automatischen Backofens, der in der Lage ist, die Art des Lebensmittels zu erkennen und die Temperatur im Inneren des Lebensmittels während des Backens zu errechnen. Die für die Temperaturberechnung benötigten Daten wurden mit mehreren Sensoren erfasst. Hierzu kam ein Infrarotthermometer, ein Infrarotabstandssensor, eine Kamera, ein Temperatursensor und ein Lambdasonde innerhalb des Ofens zum Einsatz. Ferner wurden eine Wägezelle, ein Strom- sowie Spannungs-Sensor und ein Temperatursensor außerhalb des Ofens genutzt. Die während der Aufheizphase aufgenommen Datensätze ermöglichten das Training mehrerer künstlicher neuronaler Netze, die die verschiedenen Lebensmittel in die entsprechenden Kategorien einordnen konnten, um so das optimale Backprogram auszuwählen. Zur Abschätzung der thermische Diffusivität der Nahrung, die von der Zusammensetzung (Kohlenhydrate, Fett, Protein, Wasser) abhängt, wurden mehrere künstliche neuronale Netze trainiert. Mit Ausnahme des Fettanteils der Lebensmittel konnten alle Komponenten durch verschiedene KNNs mit einem Maximum von 8 versteckten Neuronen ausreichend genau abgeschätzt werden um auf deren Grundlage die Temperatur im inneren des Lebensmittels zu berechnen. Die durchgeführte Arbeit zeigt, dass mit Hilfe verschiedenster Sensoren zur direkten beziehungsweise indirekten Messung der äußeren Eigenschaften der Lebensmittel sowie KNNs für die Kategorisierung und Abschätzung der Lebensmittelzusammensetzung die automatische Erkennung und Berechnung der inneren Temperatur von verschiedensten Lebensmitteln möglich ist.

Employment and Income of Workers on Indonesian Oil Palm Plantations: Food Crisis at the Micro Level

The importance of oil palm sector for Indonesia is inevitable as the country currently serves as the world’s largest producer of crude palm oil. This paper focuses on the situation of workers on Indonesian oil palm plantations. It attempts to investigate whether the remarkable development of the sector is followed by employment opportunities and income generation for workers. This question is posed within the theoretical framework on the link between trade liberalisation and labour rights, particularly in a labour-intensive and low-skilled sector. Based on extensive field research in Riau, this paper confirms that despite the rapid development of the oil palm plantation sector in Indonesia, the situations of workers in the sector remain deplorable, particularly their employment status and income. This also attests that trade liberalisation in the sector adversely affects labour rights. The poor working conditions also have ramifications for food security at the micro level.

Design and development of a diagonal-airflow batch dryer for spatial drying homogeneity

Das Verfahren der Lebensmitteltrocknung wird häufig angewendet, um ein Produkt für längere Zeit haltbar zu machen. Obst und Gemüse sind aufgrund ihres hohen Wassergehalts leicht verderblich durch biochemische Vorgänge innerhalb des Produktes, nicht sachgemäße Lagerung und unzureichende Transportmöglichkeiten. Um solche Verluste zu vermeiden wird die direkte Trocknung eingesetzt, welche die älteste Methode zum langfristigen haltbarmachen ist. Diese Methode ist jedoch veraltet und kann den heutigen Herausforderungen nicht gerecht werden. In der vorliegenden Arbeit wurde ein neuer Chargentrockner, mit diagonalem Luftstömungskanal entlang der Länge des Trocknungsraumes und ohne Leitbleche entwickelt. Neben dem unbestreitbaren Nutzen der Verwendung von Leitblechen, erhöhen diese jedoch die Konstruktionskosten und führen auch zu einer Erhöhung des Druckverlustes. Dadurch wird im Trocknungsprozess mehr Energie verbraucht. Um eine räumlich gleichmäßige Trocknung ohne Leitbleche zu erreichen, wurden die Lebensmittelbehälter diagonal entlang der Länge des Trockners platziert. Das vorrangige Ziel des diagonalen Kanals war, die einströmende, warme Luft gleichmäßig auf das gesamte Produkt auszurichten. Die Simulation des Luftstroms wurde mit ANSYS-Fluent in der ANSYS Workbench Plattform durchgeführt. Zwei verschiedene Geometrien der Trocknungskammer, diagonal und nicht diagonal, wurden modelliert und die Ergebnisse für eine gleichmäßige Luftverteilung aus dem diagonalen Luftströmungsdesign erhalten. Es wurde eine Reihe von Experimenten durchgeführt, um das Design zu bewerten. Kartoffelscheiben dienten als Trocknungsgut. Die statistischen Ergebnisse zeigen einen guten Korrelationskoeffizienten für die Luftstromverteilung (87,09%) zwischen dem durchschnittlich vorhergesagten und der durchschnittlichen gemessenen Strömungsgeschwindigkeit. Um den Effekt der gleichmäßigen Luftverteilung auf die Veränderung der Qualität zu bewerten, wurde die Farbe des Produktes, entlang der gesamten Länge der Trocknungskammer kontaktfrei im on-line-Verfahren bestimmt. Zu diesem Zweck wurde eine Imaging-Box, bestehend aus Kamera und Beleuchtung entwickelt. Räumliche Unterschiede dieses Qualitätsparameters wurden als Kriterium gewählt, um die gleichmäßige Trocknungsqualität in der Trocknungskammer zu bewerten. Entscheidend beim Lebensmittel-Chargentrockner ist sein Energieverbrauch. Dafür wurden thermodynamische Analysen des Trockners durchgeführt. Die Energieeffizienz des Systems wurde unter den gewählten Trocknungsbedingungen mit 50,16% kalkuliert. Die durchschnittlich genutzten Energie in Form von Elektrizität zur Herstellung von 1kg getrockneter Kartoffeln wurde mit weniger als 16,24 MJ/kg und weniger als 4,78 MJ/kg Wasser zum verdampfen bei einer sehr hohen Temperatur von jeweils 65°C und Scheibendicken von 5mm kalkuliert. Die Energie- und Exergieanalysen für diagonale Chargentrockner wurden zudem mit denen anderer Chargentrockner verglichen. Die Auswahl von Trocknungstemperatur, Massenflussrate der Trocknungsluft, Trocknerkapazität und Heiztyp sind die wichtigen Parameter zur Bewertung der genutzten Energie von Chargentrocknern. Die Entwicklung des diagonalen Chargentrockners ist eine nützliche und effektive Möglichkeit um dei Trocknungshomogenität zu erhöhen. Das Design erlaubt es, das gesamte Produkt in der Trocknungskammer gleichmäßigen Luftverhältnissen auszusetzen, statt die Luft von einer Horde zur nächsten zu leiten.