The tricot approach: an agile framework for decentralized on-farm testing supported by citizen science. A retrospective.

Matching crop varieties to their target use context and user preferences is a challenge faced by many plant breeding programs serving smallholder agriculture. Numerous participatory approaches proposed by CGIAR and other research teams over the last four decades have attempted to capture farmers' priorities/preferences and crop variety field performance in representative growing environments through experimental trials with higher external validity. Yet none have overcome the challenges of scalability, data validity and reliability, and difficulties in capturing socio-economic and environmental heterogeneity. Building on the strengths of these attempts, we developed a new data-generation approach, called triadic comparison of technology options (tricot). Tricot is a decentralized experimental approach supported by crowdsourced citizen science. In this article, we review the development, validation, and evolution of the tricot approach, through our own research results and reviewing the literature in which tricot approaches have been successfully applied. The first results indicated that tricot-aggregated farmer-led assessments contained information with adequate validity and that reliability could be achieved with a large sample. Costs were lower than current participatory approaches. Scaling the tricot approach into a large on-farm testing network successfully registered specific climatic effects of crop variety performance in representative growing environments. Tricot's recent application in plant breeding networks in relation to decision-making has (i) advanced plant breeding lines recognizing socio-economic heterogeneity, and (ii) identified consumers' preferences and market demands, generating alternative breeding design priorities. We review lessons learned from tricot applications that have enabled a large scaling effort, which should lead to stronger decision-making in crop improvement and increased use of improved varieties in smallholder agriculture.

Sensory guided selection criteria for breeding consumer-preferred sweetpotatoes in Uganda.

Prioritizing sensory attributes and consumer evaluation early in breeding trials to screen for end-user preferred traits could improve adoption rates of released genotypes. In this study, a lexicon and protocol for descriptive sensory analysis (DSA) was established for sweetpotato and used to validate an instrumental texture method for which critical values for consumer preference were set. The study comprised several phases: lexicon development during a 4-day workshop; 3-day intensive panel training; follow-up virtual training, evaluation of 12 advanced genotypes and 101 additional samples from two trials in 2021 by DSA and instrumental texture analysis using TPA double compression; and DSA, instrumental texture analysis and consumer acceptability tests on 7 genotypes in on-farm trials. The established sweetpotato lexicon comprising 27 sensory attributes enabled characterization and differentiation of genotypes by sensory profiles. Significant correlation was found between sensory firmness by hand and mouth with TPA peak positive force (r = 0.695 and r = 0.648, respectively) and positive area (r = 0.748, r = 0.715, respectively). D20, NAROSPOT 1, NASPOT 8, and Umbrella were the most liked genotypes in on-farm trials (overall liking = 7). An average peak positive force of 3700 gf was proposed as a minimum texture value for screening sweetpotato genotypes, since it corresponded with at least 46 % of consumers perceiving sweetpotatoes as just-about-right in firmness and a minimum overall liking of 6 on average. Combining DSA with instrumental texture analysis facilitates efficient screening of genotypes in sweetpotato breeding programs.

Effect of Orange-Fleshed Sweet Potato Purée and Wheat Flour Blends on ß-Carotene, Selected Physicochemical and Microbiological Properties of Bread.

Partial substitution of wheat flour with orange-fleshed sweet potato (OFSP) purée in bread can increase vitamin A intake among consumers. The study investigated the influence of wheat flour substitution with 20-50% of OFSP purée on proximate composition, color, ß-carotene, water activity, and microbial keeping quality. The moisture content, crude protein, crude fat, total ash, crude fiber, and carbohydrate in bread ranged from 28.6-32.7%, 9.9-10.6%, 5.0-5.5%, 1.9-3.2%, 1.4-1.8%, and 79.1-80.9%, respectively. ß-carotene, total ash, and crude fiber contents in bread, and Hunter color values a*, b*, chroma, and ∆E significantly increased with the addition of OFSP purée. Total viable counts (TVC), yeast, and molds in bread ranged from 2.82-3.64 log10 cfu/g and 1.48-2.16 log10 cfu/g, respectively, on the last day of storage. Water activity, TVC, and fungal counts were low in sweet potato composite bread as compared to white bread. Total ß-carotene in OFSP bread ranged from 1.9-5.4 mg/100 g (on dry weight). One hundred grams of bread portion enriched with 40% and 50% OFSP purée provides more than 50% of vitamin A dietary requirements to children aged 4-8 years. Incorporation of up to 50% OFSP purée in wheat flour produces a relatively shelf-stable, nutritious, and health-promoting functional bread.

Analysis of ß-amylase gene (Amyß) variation reveals allele association with low enzyme activity and increased firmness in cooked sweetpotato (Ipomoea batatas) from East Africa.

ß-amylase is a thermostable enzyme that hydrolyses starch during cooking of sweetpotato (Ipomoea batatas) storage roots, thereby influencing eating quality. Its activity is known to vary amongst genotypes but the genetic diversity of the beta-amylase gene (Amyß) is not well studied. Amyß has a highly conserved region between exon V and VI, forming part of the enzyme's active site. To determine the gene diversity, a 2.3 kb fragment, including the conserved region of the Amyß gene was sequenced from 25 sweetpotato genotypes. The effect of sequence variation on gene expression, enzyme activity, and firmness in cooked roots was determined. Six genotypes carrying several SNPs within exon V, linked with an AT or ATGATA insertion in intron V were unique and clustered together. The genotypes also shared an A336E substitution in the amino acid sequence, eight residues upstream of a substrate-binding Thr344. The genotypes carrying this allele exhibited low gene expression and low enzyme activity. Enzyme activity was negatively correlated with firmness (R = -0.42) in cooked roots. This is the first report of such an allele, associated with low enzyme activity. These results suggest that genetic variation within the AmyB locus can be utilized to develop markers for firmness in sweetpotato breeding.

Prioritising quality traits for gender-responsive breeding for boiled potato in Uganda.

Using quantitative, qualitative and sensorial data collected from western (Kabale) and central (Rakai) Uganda, this paper identifies and describes gender-responsive traits preferred in varieties for the boiled potato market. These traits are aggregated into a product profile to support breeding programme design and decision-making that will increase probability of variety acceptance. An interdisciplinary and participatory methodology was used to collect data on socio-economic on trait preferences, processing and organoleptics and finally, to develop a lexicon through a sensorial panel. Characteristics that were important to both men and women, such as red skin and yellow flesh, are linked to market preferences. Women-only preferred characteristics such as big size and mealiness are linked to processing efficiency and eating quality. Besides agronomic traits, breeders must consider factors such as gender roles, social norms, and market preferences traits that guide farmers and other food chain actors in their selection of new varieties.

Development of a food product profile for boiled and steamed sweetpotato in Uganda for effective breeding.

This study sought to understand user preferences of raw, boiled and steamed sweetpotato, a staple food in Uganda. A sequential methodology involving state of knowledge review, gendered food mapping, processing diagnosis and consumer testing was used in Lira and Kamwenge districts. Preferred raw sweetpotato characteristics were large roots (≥ 3 cm diameter) with a sweet taste, smooth skin and hard texture, while mealiness, sweet taste and good sweetpotato smell were important attributes for boiled sweetpotato. Processors, mostly women, highlighted ease of peeling and sappiness of raw roots. There were gender differences in quality characteristic preferences and perceived importance. The released variety, NASPOT 8, had the highest overall liking in Kamwenge and was well liked in Lira. Penalty analysis of consumer data showed that sweetness and firmness were key drivers of overall liking. The results will support breeding programmes in meeting specific end-user product profiles, selection criteria and uptake of new varieties.

Processing methods affect phytochemical contents in products prepared from orange-fleshed sweetpotato leaves and roots.

Phytochemicals enhance human health by acting antagonistically on incidences of cancer and other chronic diseases. They are considered indispensable in a variety of nutraceutical, pharmaceuticals, and medicinal and cosmetic applications. This study evaluated the effects of common processing methods on inherent phytochemical content in the roots and leaves of orange-fleshed sweetpotato (OFSP) varieties called Kabode and SPK031. Yellosp and Whitesp, which are local sweetpotato varieties, were also included as check for roots and leaves, respectively. The sweetpotato products prepared for phytochemical analysis were boiling roots and leaves, frying chips and crisps, baking bread (for roots only), and fermenting and dehydrating leaves. Phytochemicals that were assessed included vitamin C, total phenolics and flavonoids, tannins, phytates, and soluble oxalates. Results indicated that retention of vitamin C was highest in boiled roots (85%-95%), followed by fries (71%-94%) and crisps (44%-76%), whereas the least retention was in bread (4%-11%) and leaves (0%-27%). Total phenolics, flavonoids, and antioxidant activity in leaves significantly (p < .05) varied with the type of processing. Higher retention of these phytochemicals was observed in processed roots but was lowest in bread. Boiling retained more than 100% of all carotenoids, while fermenting and drying the leaves retained 58-62 and 22%-48%, respectively. Frying retained more than 100% of the ß-carotene in the roots, while boiling retained 96%-100%. All processing methods significantly (p < .05) reduced antinutrients in leaves and roots. Fermentation of leaves had higher reduction of oxalates, tannins, and phytates, while boiling had the least effect. It is concluded that traditional boiling enhances phytochemical retention in roots but degrades most of them in leaves.

Starch digestibility and ß-carotene bioaccessibility in the orange- fleshed sweet potato puree-wheat bread.

Vitamin A is essential for vision, human health, growth, immune function, and reproduction. Its deficiency leads to anemia, xerophthalmia, and growth reduction in children. Foods enriched with naturally occurring carotenes have the potential, in this regard, and orange-fleshed sweet potato (OFSP) stands out tall as it is rich in ß-carotene (ßC), a provitamin A carotenoid. In view of developing OFSP-based functional foods to address the vitamin A deficiency (VAD) issues, herein, OFSP puree-wheat composite breads have been prepared at 10% to 50% OFSP puree concentrations and bioaccessibility of ßC has been estimated. The total ßC is found to be 4.3, 9.2, 16.5, 23.3, and 33.6 µg/g in 10, 20, 30, 40, and 50% OFSP bread, respectively. The corresponding calculated retinol activity equivalents (RAE) are 30.9, 66.4, 119.5, 170.4, and 246.2 RAE/100 g. The efficiency of micellarization of all-trans-ßC, 13-cis ßC, and 9-cis ßC after simulated oral, gastric, and small intestinal digestion are 1.4% to 6.4%, 1.4% to 7.2%, and 1.1% to 6.9%, respectively. The amount of micellarized ßC correlates linearly with the OFSP concentration in the bread. Furthermore, in vitro starch digestion decreases with significant reduction in the Rapidly Digestible Starch (RDS) amount coupled with increase in the Slowly Digestible Starch (SDS) and Resistant Starch (RS) fractions. Overall, OFSP-wheat composite bread holds adequate amount of provitamin A carotenoids. The amount of bioaccessible ßC coupled with altered starch digestion of the OFSP wheat breads highlight their usefulness as novel functional foods that could address the VAD as well as glycemic issues toward improving human health.

Effect of food safety training on behavior change of food handlers: A case of orange-fleshed sweetpotato purée processing in Kenya.

Sweetpotato purée processing is new to Kenya and a rapidly growing value addition activity among informal, small, and medium-sized food enterprises (SMEs) in sub-Saharan Africa (SSA). Inadequate knowledge of food safety and poor hygiene practices by food handlers, low level of compliance with Good Manufacturing Practices (GMPs), and microbial contamination are major food safety challenges in orange-fleshed sweetpotato (OFSP) purée processing in Kenya. The extent of food safety training in enhancing food safety in rural-based SMEs and food processing environments has not been fully investigated. This study aimed at evaluating the impact of food safety training on food safety knowledge and hygiene practices of food handlers and in control of microbial contamination in OFSP purée processing in Kenya. Pre- and post-food safety training assessments were conducted to determine food handler's (N = 14) knowledge and practices on food safety. Food, water, and swab samples (n = 62) from the processing environment were collected before and two months after the training and analyzed for food hygiene indicator microorganisms. The findings indicate a significant (p < 0.05) improvement in overall food safety knowledge and practices of food handlers after the training. Poor knowledge scores were exhibited on aspects of cross-contamination, cleaning, and sanitation but these significantly (p < 0.05) improved after the training. Similarly, microbial counts on food equipment surfaces, installations, personnel hands, and in the final product (OFSP purée) significantly (p < 0.05) declined to acceptable levels after the food safety training. Total counts, yeasts and molds, S. aureus, Enterobacteriaceae, and total coliforms counts in the packaged OFSP purée were 2.6, 1.8, 1.5, 1.9, and 1.2 LOG CFU/g respectively hence suitable for its current application as an ingredient in baked products. The findings from this study indicate food safety training as an appropriate tool for improving food handler's knowledge and hygiene practices as well as enhancing microbial safety and quality of processed foods in SMEs if necessary food safety support resources are provided.

Do Market-oriented Engendered Agriculture-health Interventions Affect Household Nutrition Outcomes: Evidence from an Orange-fleshed Sweetpotato Project in Rwanda.

The number of agricultural interventions promoting biofortified crops as a strategy to combat micronutrient malnutrition have increased significantly during the past decade. These interventions aim to improve the intake of key nutrients and sometimes other nutrition outcomes. In this study, we assess the impact of a market-oriented gender-sensitive agriculture-health project on household food consumption and food security. We use gender-disaggregated data from 842 sweetpotato farmers and a series of econometric techniques to assess the project's impact on food consumption household food security. The study finds unambiguous and strong impact of the project on both household food consumption and food security. Moreover, female-headed participant households benefitted much more from participation than did male-headed households. We further find that nonparticipant households would also have benefitted had they participated. The findings imply the importance of designing market-focused projects with a gender lens. They also imply that market-oriented agriculture-sensitive interventions do not necessarily harm the nutritional status of farm households.

Assessing the Coverage of Biofortified Foods: Development and Testing of Methods and Indicators in Musanze, Rwanda.

BACKGROUND: Biofortification of staple crops has the potential to increase nutrient intakes and improve health outcomes. Despite program data on the number of farming households reached with and growing biofortified crops, information on the coverage of biofortified foods in the general population is often lacking. Such information is needed to ascertain potential for impact and identify bottlenecks to parts of the impact pathway. OBJECTIVES: We aimed to develop and test methods and indicators for assessing household coverage of biofortified foods. METHODS: To assess biofortification programs, 5 indicators of population-wide household coverage were developed, building on approaches previously used to assess large-scale food fortification programs. These were 1) consumption of the food; 2) awareness of the biofortified food; 3) availability of the biofortified food; 4) consumption of the biofortified food (ever); and 5) consumption of the biofortified food (current). To ensure that the indicators are applicable to different settings they were tested in a cross-sectional household-based cluster survey in rural and peri-urban areas in Musanze District, Rwanda where planting materials for iron-biofortified beans (IBs) and orange-fleshed sweet potatoes (OFSPs) were delivered. RESULTS: Among the 242 households surveyed, consumption of beans and sweet potatoes was 99.2% and 96.3%, respectively. Awareness of IBs or OFSPs was 65.7% and 48.8%, and availability was 23.6% and 10.7%, respectively. Overall, 15.3% and 10.7% of households reported ever consuming IBs and OFSPs, and 10.4% and 2.1% of households were currently consuming these foods, respectively. The major bottlenecks to coverage of biofortified foods were awareness and availability. CONCLUSIONS: These methods and indicators fill a gap in the availability of tools to assess coverage of biofortified foods, and the results of the survey highlight their utility for identifying bottlenecks. Further testing is warranted to confirm the generalizability of the coverage indicators and inform their operationalization when deployed in different settings.

Phytochemicals in Leaves and Roots of Selected Kenyan Orange Fleshed Sweet Potato (OFSP) Varieties.

This study reports the inherent phytochemical contents in leaves and roots of nine sweet potato varieties from Kenya. Results indicated that vitamin C content varied significantly (P < 0.05) among the sweet potato varieties regardless of the plant part, leaves having significantly (P < 0.05) higher levels than in the roots. Total flavonoids and phenolic compounds differed significantly (P < 0.05) among varieties, higher values were found in leaves than in roots. Flavonoid contents in roots ranged from below detectable limits (Whitesp) to 25.8 mg CE/100 g (SPK031), while in leaves it ranged from 4097 to 7316 mg CE/100 g in SPK4 and Kenspot 5, respectively. Phenolic content was below detectable limits in the roots of whitesp but it was in substantial amounts in orange fleshed varieties. The ß-carotene content was significantly (P < 0.05) higher in leaves (16.43-34.47 mg/100 g dry weight) than in roots (not detected-11.1 mg/100 g dry weight). Total and phytic phosphorus were directly correlated with phytate contents in leaves and the roots. Tannins and soluble oxalates varied significantly (P < 0.05) with variety and plant part being higher in leaves. The current information is important for ration formulations and dietary recommendations utilizing sweet potato leaves and roots. Future studies on effects of processing methods on these phytochemicals are recommended.

Correction: Diversity analysis and genome-wide association studies of grain shape and eating quality traits in rice (Oryza sativa L.) using DArT markers.

[This corrects the article DOI: 10.1371/journal.pone.0198012.].

Carotenoids retention in biofortified yellow cassava processed with traditional African methods.

BACKGROUND: Biofortified yellow cassava is being cultivated in countries with high cassava consumption to improve its population's vitamin A status. The carotenoid retention in biofortified cassava when processed as boiled, fufu, and chikwangue was evaluated in this study. Commercial biofortified varieties Kindisa and Vuvu and the experimental genotypes MVZ2011B/360 and MVZ2012/044 were used. Fresh cassava roots were processed as boiled, fufu, and chikwangue. Provitamin A carotenoids (pVACs) content of fresh and processed cassava was measured by high-performance liquid chromatography, and total carotenoids was measured by spectrophotometer. RESULTS: pVACs content of fresh peeled cassava was 1.79-6.65 µg g-1 on a fresh weight basis, whereas in boiled cassava, fufu, and chikwangue the pVACs content was 1.71-6.91 µg g-1 , 0.04-0.37 µg g-1 , and 0.52-1.75 µg g-1 respectively. True retention of carotenoids after cooking was 93.2-96.8%, 0.8-3.1%, and 4.0-18.1% for boiled cassava, fufu, and chikwangue respectively. Significant total carotenoids loss was observed during storage. CONCLUSION: The results indicated that biofortified boiled cassava could be an effective food product to improve pVACs intake in areas where vitamin A deficiency exists, and processing of chikwangue and fufu should be improved before promoting biofortified cassava in vitamin-A-deficient areas with high cassava consumption. © 2018 The Authors. Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Postharvest quality of two orange-fleshed sweet potato [Ipomoea batatas (L) Lam] cultivars as influenced by organic soil amendment treatments.

Two orange-fleshed sweet potato cultivars: Apomuden and "Nane" were grown on cow dung-, chicken manure-, compost-amended soils, and untreated soil. Apomuden is a variety, while "Nane" is being evaluated to be released in Ghana. The storage roots (SRs) were harvested at 3 months, cured by heaping the SRs and covering with the sweet potato foliage for 7 days in the field. The cured SRs were kept in an evaporative cool chamber to study the effect of soil amendment treatments on weight loss, rot, some nutrient composition, and sensory attributes. Boiled SRs were assessed by 70 untrained panelists after 7 weeks of storage based on the following: general appearance, sweetness, finger-feel firmness, and overall acceptability using a 5-point hedonic scale (1 = dislike extremely to 5 = like extremely). Percent rot for "Nane" showed a linear trend, while that of Apomuden was nonlinear. Both cultivars showed similar trends in terms of cumulative weight loss with "Nane" recording lower weight loss compared with Apomuden. A significant (p < 0.001; r = 0.71) strong positive correlation was observed between weight loss and rots. "Nane" had higher dry matter (37.15% vs. 30.19%; p < 0.001, respectively) and starch content (59.16% vs. 51.86%; p < 0.001, respectively) than Apomuden. Stored SRs grown on chicken manure-amended soil recorded the highest protein (6.41%; p < 0.001) and ß-carotene (16.64 mg/100 g; p < 0.001) content than the other treatments. There was a 35% decline in ß-carotene for Apomuden, while "Nane" increased by 24% at the end of the 7-week storage. "Nane," the cultivar with high dry matter content had good storage properties than Apomuden. Stored SRs cultivated on soils amended with chicken manure had higher ß-carotene and protein content. All sensory attributes ranged from 3.35 to 3.68 indicating a good consumer preference for both cultivars irrespective of the soil amendment treatment applied.

The physiochemical properties and shelf-life of orange-fleshed sweet potato puree composite bread.

Value addition of orange-fleshed sweet potato (OFSP) increases diversified utilization of this crop, which is rich in provitamin A carotenoids. OFSP bread, in which 30%-45% of wheat flour is replaced with OFSP puree, has been successfully commercialized in Kenya. However, the effect of this substitution on the bread's physiochemical properties and its shelf-life are currently unknown. This study was designed to determine the physiochemical properties and shelf-life of OFSP puree-wheat flour composite bread (30% puree), compared to standard, 100% wheat flour, bread. Freshly baked bread samples were stored at 7, 20, 25, and 30°C, and monitored for moisture content, water activity, color, texture, volume, carotenoids, and microbial load. The moisture content, ß-carotene content, and color of bread significantly decreased with increase in storage temperature and time (p < 0.05). Bread made with OFSP puree had a longer shelf-life, showing spoilage on day six compared with the white bread, which spoiled on the fourth day. This is attributed to the significantly higher water activity in white bread than in the OFSP bread. The substitution of wheat with OFSP puree resulted in reduced extensibility of gluten, thus, specific volume of white bread was significantly (p < 0.05) higher than that in OFSP puree bread. Refrigeration increased crumb firmness, chewiness and cohesiveness in both types of bread. In conclusion, OFSP puree increases the water binding capacity of the bread, which reduces water activity and increases its shelf-life.

Effects of Acidification and Preservatives on Microbial Growth during Storage of Orange Fleshed Sweet Potato Puree.

Orange Fleshed Sweet Potato (OFSP) puree, a versatile food ingredient, is highly perishable limiting its use in resource constrained environments. It is therefore important to develop shelf-stable puree. A challenge test study was carried out to determine the effect of combinations of chemical preservatives and acidification on microbial growth in stored puree. Puree was prepared and treated as follows: control (A); 0.05% potassium sorbate+0.05% sodium benzoate+1% citric acid (B); 0.1% potassium sorbate+0.1% sodium benzoate+1% citric acid (C); 0.2% potassium sorbate+0.2% sodium benzoate+1% citric acid (D); 1% citric acid (E). Samples were inoculated with Escherichia coli and Staphylococcus aureus at levels of 5.2 x 109 cfu/100g and 1.5 x 109 cfu/100g, respectively, before being evaluated during storage for 10 weeks at prevailing ambient temperature (15-25°C) and refrigeration temperature (4°C). Total aerobic counts, yeasts, and molds were also evaluated. E. coli and S. aureus counts declined significantly (p<0.05) by 4 log cycles in all puree treatments except for control and puree with only citric acid. Total viable count, yeasts, and molds were completely inhibited except for puree with only citric acid. Combination of chemical preservatives and acidification is effective in inhibiting pathogens and spoilage microorganisms in sweet potato puree.

Good Manufacturing Practices and Microbial Contamination Sources in Orange Fleshed Sweet Potato Puree Processing Plant in Kenya.

Limited information exists on the status of hygiene and probable sources of microbial contamination in Orange Fleshed Sweet Potato (OFSP) puree processing. The current study is aimed at determining the level of compliance to Good Manufacturing Practices (GMPs), hygiene, and microbial quality in OFSP puree processing plant in Kenya. Intensive observation and interviews using a structured GMPs checklist, environmental sampling, and microbial analysis by standard microbiological methods were used in data collection. The results indicated low level of compliance to GMPs with an overall compliance score of 58%. Microbial counts on food equipment surfaces, installations, and personnel hands and in packaged OFSP puree were above the recommended microbial safety and quality legal limits. Steaming significantly (P < 0.05) reduced microbial load in OFSP cooked roots but the counts significantly (P < 0.05) increased in the puree due to postprocessing contamination. Total counts, yeasts and molds, Enterobacteriaceae, total coliforms, and E. coli and S. aureus counts in OFSP puree were 8.0, 4.0, 6.6, 5.8, 4.8, and 5.9 log10 cfu/g, respectively. In conclusion, equipment surfaces, personnel hands, and processing water were major sources of contamination in OFSP puree processing and handling. Plant hygiene inspection, environmental monitoring, and food safety trainings are recommended to improve hygiene, microbial quality, and safety of OFSP puree.

Peanut butter increases the bioavailability and bioconversion of kale ß-carotene to vitamin A.

BACKGROUND AND OBJECTIVES: Kale is a rich source of provitamin A- ß-carotene. This study used intrinsically labeled kale [2H9] ß-carotene to determine the effect of peanut butter on the bioconversion of kale ß-carotene to vitamin A in preschool children. METHODS AND STUDY DESIGN: Preschool children (n=37; age 12-36 mo) were randomly assigned to 50 g cooked kale (1.5 mg ß-carotene content) with either 33 g peanut butter (PBG) or with 16 g lard (LG) and a reference dose of 1 mg [13C10] retinyl acetate capsule. Blood samples were processed to serum and analyzed by Negative Chemical Ionization-Gas Chromatography Mass Spectrometry (NCI-GCMS) for the enrichments of [2H] retinol from kale [2H9] ß-carotene and [13C10] retinol from reference dose. RESULTS: The area under curves (AUCs) of molar enrichment at days 1, 2, 3, 6, 15, and 21 after the labeled doses was 56.3±10.5 and 84.8±16.2 (nmole) for [2H] retinol from LG and PBG kale [2H9] ß-carotene, respectively. The AUC of [13C10] retinol from reference dose was 432.6±54.9 (LG) and 560.3±156.7 (nmole) (PBG), respectively. The calculated ß-carotene conversion factors were 13.4±3.1 and 11.0±3.9 to 1 (p>0.05) by weight for LG and PBG, respectively. CONCLUSIONS: This study showed that peanut butter enhances the vitamin A value of kale.