Despite concerted efforts at agricultural development over many years, millions of people in developing countries still suffer from poverty and under-nutrition. New crop varieties, such as those released during the green revolution in Asia, increased farmers' income and reduced the level of under-nutrition. In recent years, while the speed of the development of conventional breeding technology has slowed, biotechnology has developed rapidly. In 2005, about 8.5 million farmers in 21 countries grew transgenic crops. Transgenic rice has not been commercially released on a large scale, but progress has been made in developing varieties with potential to increase yield and reduce input costs. In this context, this research aims to provide empirical evidence on the potential effects of introducing transgenic rice on farm households' income and nutritional well-being in Bangladesh, including the impacts on their current nutritional status and nutritional vulnerability over time. To this end, two econometric models are constructed and estimated. A farm household model is employed to project farm households' production and consumption responses to introducing improved rice varieties such as transgenic rice. The model estimates the profit effect of introducing transgenic rice. The influence of the profit effect on farmers' consumption decisions is then considered. Due to the ex ante nature of this research and data limitations, the effects of transgenic rice are assumed to be similar to that of previous high yielding varieties (HYVs), and the impact of transgenic rice on farm household profit is assumed to be similar to the effect of the percentage of rice area in HYVs and the yield effect of transgenic rice is the same as HYVs. On the production side, the supply of three outputs- rice, all other crops and animal products- and demand of labor and fertilizer were estimated. On the consumption side, both poor and non-poor households' demand for rice, wheat/other food, pulse, oil, vegetables/fruits, meat/egg/ milk, fish, and spices were estimated. Based on the parameter estimates, the calorie intake and protein intake elasticities with respect to introducing transgenic rice were computed. The results indicate that the total profit elasticity with respect to the percentage of rice area in HYVs is 0.08. The calorie elasticity with respect to the percentage of rice area in HYVs ranges from 0.062 in non-poor to 0.074 in poor households, and the protein elasticity ranges from 0.075 in non-poor to 0.084 in poor households. The results indicate that transgenic rice is likely to play a positive role in improving farm households' nutritional status in terms of total calorie/protein intake. The magnitude, however, is likely to be moderate, if only the profit effect is considered. A consumption forecasting model is used to examine farmers' nutritional vulnerability a probabilistic concept defined as having a high probability now of suffering a shortfall in the future. It is assumed that when exposed to risk, farmers' consumption decisions have already considered their risk coping strategies. The effect of transgenic rice is reflected by its impact on farm income. Farm households' calorie intake in the future (hunger season) was predicted by a multivariate regression function with the logarithmic daily per resident calorie intake as the dependent variable. The independent variables include variables that represent households' income, flood exposure, assets, and demographic composition. Farm households' nutritional vulnerability profiles, based on the estimation of ex ante mean and variance, indicate that vulnerability exists among surveyed rice farm households. The model also predicts that the income increase induced by introducing transgenic rice will reduce each individual household's probability of suffering a future consumption shortfall and subsequently will reduce its vulnerability. The overall vulnerability profile of farm households improves in Bangladesh. / Ph. D.

Plants are potential sources of valuable recombinant and native proteins that can be purified for pharmaceutical, nutraceutical, and food applications. Transgenic rice and corn germ were evaluated for the production of novel protein products. This dissertation addresses: 1) the extraction and purification of the recombinant protein, human lysozyme (HuLZ), from transgenic rice and 2) the processing of dry-milled corn germ for the production of high protein germ and corn protein concentrate (CPC). The factors affecting the extraction and purification of HuLZ from rice were evaluated. Ionic strength and pH was used to optimize HuLZ extraction and cation exchange purification. The selected conditions, pH 4.5 with 50 mM NaCl, were a compromise between HuLZ extractability and binding capacity, resulting in 90% purity. Process simulation was used to assess the HuLZ purification efficiency and showed that the processing costs were comparable to native lysozyme purification from egg-white, the current predominant lysozyme source. Higher purity HuLZ (95%) could be achieved using pH 4.5 extraction followed by pH 6 adsorption, but the binding capacity was unexpectedly reduced by 80%. The rice impurity, phytic acid, was identified as the potential cause of the unacceptably low capacity. Enzymatic (phytase) treatment prior to adsorption improved purification, implicating phytic acid as the primary culprit. Two processing methods were proposed to reduce this interference: 1) pH 10 extraction followed by pH 4.5 precipitation and pH 6 adsorption and 2) pH 4.5 extraction and pH 6 adsorption in the presence of TRIS counter-ions. Both methods improved the binding capacity from 8.6 mg/mL to >25 mg/mL and maintained HuLZ purity. Processing of dry-milled corn germ to increase protein and oil content was evaluated using germ wet milling. In this novel method, dry-milled germ is soaked and wet processed to produce higher value protein products. Lab-scale and pilot-scale experiments identified soaking conditions that reduced germ starch content, enhanced protein and oil content, and maintained germ PDI (protein dispersibility index). Soaking at neutral pH and 25 degrees C maintained germ PDI and improved CPC yield from defatted germ flour. CPC with greater than 75% protein purity was produced using protein precipitation or membrane filtration.