No abstract

Ninety‐four different sweetpotato cultivars with various dry matter contents were used to process crisps and the end product was analyzed to determine the oil content. A linear relationship between dry matter content in raw sweetpotato storage roots and the level of oil uptake in crisps was determined. Sweetpotato storage roots with 23–25% (fwb) dry matter content gave crisps containing between 21% and 32% of oil, while the fat contents of crisps from potatoes having a similar dry matter content were 36% and more. Consequently, storage roots from Kemb 10 sweetpotato cultivar having a high dry matter content of 32.9% (fwb), either in boiled and mashed, raw and grated, or flour form, were used to partially substitute wheat flour in processing fried products. It has been found that boiled and mashed sweetpotato lessens oil uptake in mixtures of fried products such as “mandazis” (doughnuts).

French fries (chips) are increasingly becoming indispensable in menus of many restaurants and hotels in major Kenyan towns due to their relatively lower consumer prices compared to other foods. When foods are deep-oil-fried, the amount of oil absorbed by the food is important since nutritionally, the amount of oil absorbed has a marked bearing on the number of calories supplied by the food. Fried foods such as chips may contain a considerable amount of oil to such extent that their consumption is of concern to nutritionists who advocate for a decrease or an increase of fat content in the diet depending on the part of the world where they are based. Chips with lower oil content and equivalent sensory attributes are expected to be highly accepted by consumers. The influence of potato cultivar and stage of maturity on uptake of oil into chips was investigated using eight Kenyan cultivars including five varieties (Tigoni, Desiree, Dutch Robyjn, Kenya Karibu, and Kenya Sifa) and three promising potato clones coded as 393385.47, 391696.96 and 393385.39. The eight cultivars were grown under cultural standard conditions at the National Potato Research Centre, Tigoni. The crop was dehaulmed two weeks before harvesting and allowed to cure at ambient air conditions (15-19 o C/86-92 % RH) for three weeks. The potatoes were harvested at 90 or 120 days after planting. The variety of potato used had a significant effect (P≤0.05) on oil uptake, with Dutch Robyjn having the lowest oil content. The cellular structures may have affected the oil uptake into the chips by influencing solid content, moisture loss during frying or damage done to original anatomy during processing. Harvesting before maturity significantly (P≤0.05) increased oil content of chips when compared to those prepared from mature tubers. There is need for processors to wisely choose the potato cultivar in order to produce French fries with low oil content.

Understanding the impact of climate change remains vital for food safety and public health. Of particular importance is the influence of climatic conditions on the growth of Aspergillus flavus and production of their toxins. Nevertheless, little is known about the actual impact of climate change on the issue. Setting up of relevant measures to manage the impact has therefore become a daunting task especially in developing nations. Therefore, this study aimed at providing adaptation and mitigation options to manage this risk with a special focus on Kenya where cases of aflatoxicosis have been recurrent. We used a systematic literature review of review and research articles, with limited searching but systematic screening to explore available qualitative and quantitative data. Projections from the data, showed that on average, a 58.9% increase of aflatoxin contamination in the Central and Western parts and a decrease of 44.6% in the Eastern and Southern parts is expected but with several possible scenarios. This makes the impact of climate change on aflatoxin contamination in Kenya complex. To protect the public and environment from the negative impact, a regulatory framework that allows for an integrated management of aflatoxins in a changing climate was proposed. The management practices in the framework are divided into agronomic, post-harvest and institutional levels. Given the multiple points of application, coordination amongst stakeholders along the chain is fundamental. We therefore proposed a complimentary framework that allows the food safety issues to be addressed in an integrated manner while allowing for transparent synergies and trade-offs (in implementing the measures). A policy-oriented foresight should be carried out to provide policy based evidence for the applicability of the proposed adaptation and mitigation measures.

Epidemiological studies show a definite connection between areas of high aflatoxin content and a high occurrence of human hepatocellular carcinoma (HCC). Hepatitis B virus in individuals further increases the risk of HCC. The two risk factors are prevalent in rural Kenya and continuously predispose the rural populations to HCC. A quantitative cancer risk assessment therefore quantified the levels at which potential pre- and postharvest interventions reduce the HCC risk attributable to consumption of contaminated maize and groundnuts. The assessment applied a probabilistic model to derive probability distributions of HCC cases and percentage reductions levels of the risk from secondary data. Contaminated maize and groundnuts contributed to 1,847 ± 514 and 158 ± 52 HCC cases per annum, respectively. The total contribution of both foods to the risk was additive as it resulted in 2,000 ± 518 cases per annum. Consumption and contamination levels contributed significantly to the risk whereby lower age groups were most affected. Nonetheless, pre- and postharvest interventions might reduce the risk by 23.0-83.4% and 4.8-95.1%, respectively. Therefore, chronic exposure to aflatoxins increases the HCC risk in rural Kenya, but a significant reduction of the risk can be achieved by applying specific pre- and postharvest interventions.