@article{allan_johanningsmeier_nakitto_guambe_abugu_v. pecota_yencho_2024, title={Baked sweetpotato textures and sweetness: An investigation into relationships between physicochemical and cooked attributes}, volume={21}, ISSN={["2590-1575"]}, DOI={10.1016/j.fochx.2023.101072}, abstractNote={Sweetpotato varieties vary greatly in perceived textures and sweetness. This study identified physicochemical factors that influence these attributes in cooked sweetpotatoes. Fifteen genotypes grown on three plots were baked and evaluated by a trained descriptive sensory analysis panel for sweetness and 13 texture attributes. Mechanical parameters were measured by texture profile analysis (TPA); and composition (starch, cell wall material, sugar contents), starch properties (thermal, granule type ratios, granule sizes), and amylase activities were characterized. TPA predicted fracturability and firmness well, whereas starch and sugar contents, B-type starch granule ratio, and amylase activities influenced prediction of mouthfeel textures. Sweetness perception was influenced by perceived particle size and sugar contents; and maltose generation during baking was highly correlated with raw sweetpotato starch content. These relationships between physicochemical sweetpotato properties and baked textures and sweetness could benefit breeders and processors in selecting biochemical traits that result in consumer preferred products.}, journal={FOOD CHEMISTRY-X}, author={Allan, Matthew C. and Johanningsmeier, Suzanne D. and Nakitto, Mariam and Guambe, Osvalda and Abugu, Modesta and V. Pecota, Kenneth and Yencho, G. Craig}, year={2024}, month={Mar} }
 @article{allan_read_johanningsmeier_2023, title={Impact of sweetpotato starch structures, thermal properties, and granules sizes on sweetpotato fry textures}, volume={137}, ISSN={["1873-7137"]}, DOI={10.1016/j.foodhyd.2022.108377}, abstractNote={Sweetpotato French fry (SPFF) textures have been previously correlated with starch contents, but little is known about the relationship of starch properties with SPFF textures. Associations of SPFF textures with starch properties were explored by comparing starch thermal properties (gelatinization temperatures and starch type percentages), amylopectin chain length distributions, and granules sizes among genotypes that produced a wide range of SPFF textures. SPFF textures were modeled with these starch data and raw sweetpotato compositions to investigate the impact of starch attributes on SPFF textures. Starch structures, thermal properties, and granule sizes varied among genotypes. In general, starches from orange-fleshed sweetpotatoes had lower degrees of polymerization (DP) (more DP 6–9 chains and fewer DP 18–25 chains), more B-type starch, and lower gelatinization temperatures than yellow or cream-fleshed genotypes, but no differences in granule size distributions. Predictions of fry textures using raw composition were significantly improved when starch properties were included. Starch thermal properties, particularly the percentage of A-type starch, most influenced the prediction of SPFF textures. Structural equation modeling identified causal relationships between SPFF textures and starch properties. Starch thermal properties and the interaction with α-amylase levels had the strongest correlations with SPFF textures. Alongside raw compositions, starch thermal properties provide valuable information for predicting SPFF textures that could be used to make varietal selections by processors and breeders.}, journal={FOOD HYDROCOLLOIDS}, author={Allan, Matthew C. and Read, Quentin D. and Johanningsmeier, Suzanne D.}, year={2023}, month={Apr} }
 @article{allan_read_johanningsmeier_2023, title={Impact of sweetpotato starch structures, thermal properties, and granules sizes on sweetpotato fry textures (vol 137, 108377, 2023)}, volume={139}, ISSN={["1873-7137"]}, DOI={10.1016/j.foodhyd.2023.108559}, journal={FOOD HYDROCOLLOIDS}, author={Allan, Matthew C. and Read, Quentin D. and Johanningsmeier, Suzanne D.}, year={2023}, month={May} }
 @article{allan_johanningsmeier_2022, title={Sweetpotato chip texture and fat content: Effects of enzymatic modification of cell wall polymers}, ISSN={["1750-3841"]}, DOI={10.1111/1750-3841.16267}, abstractNote={Impacts of cell wall polymers on sweetpotato chip texture and fat content were investigated through enzymatic modification. Covington sweetpotato slices were treated with cellulase, hemicellulase, pectinase, pectin methyl esterase, protease, the enzyme blend Viscozyme, or no enzymes (control) at 40-45°C for 0.5-2 h. Treated slices were blanched, dried, and fried in triplicate per experimental condition. Breaking forces of 20 chips per frying replicate were measured followed by chip fat, moisture, sugar, alcohol insoluble solids, glass transition temperature, and color analyses. Untreated slices from each batch (daily check) were fried and analyzed to account for starting material variability. Viscozyme and protease-treated chips had the greatest reduction in breaking force from untreated chips (-30.9% and -23.7%, respectively), while pectin methyl esterase-treated chips had the lowest reduction in breaking force (-9.0%). Chips treated with Viscozyme for 2 h were 6.7-6.3 percentiles lower in fat than the control. Principal component analysis elucidated that chip breaking force was associated with unfried slice puncture force, alcohol insoluble solids, and chip color, and chip fat content was inversely associated with maltose content and glass transition temperature. Breaking down multiple cell wall polysaccharides or structural proteins weakened chip textures, while strengthening the pectic fraction resulted in harder chips. Chip fat reduction also occurred when multiple cell wall polysaccharides were broken down. Therefore, cell wall polymers impact sweetpotato chip texture and fat contents, and their attributes should be considered when selecting cultivars and processes for sweetpotato chips. PRACTICAL APPLICATION: Sweetpotato chips are an increasingly popular snack, but there is little understanding how cell wall polymers impact chip textures and fat contents. Raw sweetpotato slices were enzymatically treated to selectively modify cell wall polymers before frying. Chip breaking forces were lowered by protease or Viscozyme (cell wall enzyme blend) treatments, while breaking forces were increased with pectin methyl esterase. In addition, chip fat contents were reduced by the Viscozyme treatment. Since cell wall modifications could impact chip texture and fat content, cell wall polymer attributes should be considered in selection and processing of sweetpotatoes for chip manufacturing.}, journal={JOURNAL OF FOOD SCIENCE}, author={Allan, Matthew C. and Johanningsmeier, Suzanne D.}, year={2022}, month={Aug} }
 @article{allan_mauer_2022, title={Variable Effects of Twenty Sugars and Sugar Alcohols on the Retrogradation of Wheat Starch Gels}, volume={11}, ISSN={["2304-8158"]}, DOI={10.3390/foods11193008}, abstractNote={Starch retrogradation is desirable for some food textures and nutritional traits but detrimental to sensory and storage qualities of other foods. The objective of this study was to determine the impact of sweetener structure and concentration on the retrogradation of wheat starch gels. The effects of 20 sweeteners selected based on common food usage and stereochemical structures of interest, and ranging in concentration from 10 to 50%w/w, on the retrogradation of wheat starch gels were monitored spectrophotometrically over time. The sweeteners were sucrose, xylose, ribose, glucose, galactose, fructose, mannose, mannitol, L-sorbose, xylitol, tagatose, allulose, maltose, lactose, isomaltulose, isomalt, sorbitol, maltitol, and raffinose. Retrogradation rates and amounts were compared by Avrami equation rate constants (k = 0.1–0.7) and absorbance values measured on day 28 (Abs = 0.1–1.0), respectively. Both sweetener concentration and type significantly affected retrogradation. Gels made with sugar alcohols and high sweetener concentrations (≈≥40%) tended to retrograde more and faster, whereas gels made with sugars and low sweetener concentrations tended to have lower retrogradation rates and amounts. Sweeteners with more equatorial and exocyclic hydroxyl groups (e.g., glucose and maltitol) and those with larger molar volumes (e.g., isomaltulose and raffinose) tended to increase the rate and amount of retrogradation, particularly at higher concentrations. The impact of sweeteners on retrogradation was a balance of factors that promoted retrogradation (intermolecular interactions and residual short-range molecular order) and inhibiting behaviors (interference at crystallization sites), which are influenced by sweetener concentration and structure. Understanding which sweeteners at which concentrations can be used to promote or inhibit retrogradation is useful for product formulation strategies.}, number={19}, journal={FOODS}, author={Allan, Matthew C. and Mauer, Lisa J.}, year={2022}, month={Oct} }
 @article{allan_marinos_johanningsmeier_sato_truong_2021, title={Relationships between isolated sweetpotato starch properties and textural attributes of sweetpotato French fries}, volume={86}, ISSN={["1750-3841"]}, DOI={10.1111/1750-3841.15725}, abstractNote={Sweetpotato French fry (SPFF) textures have been associated with dry matter and starch contents, but these do not fully account for all textural differences. This study investigated the relationships between the physicochemical properties of sweetpotato starch and textural attributes of sweetpotato fries. Starches from 16 sweetpotato genotypes that varied in dry matter content were isolated and analyzed. The amylose content, pasting temperatures and viscosities, and textural properties of equilibrated starch gels were measured. Correlational analysis was performed with the respective SPFF mechanical and sensory texture attributes. Sweetpotato starch amylose content ranged from 17.3% to 21.1%, and the pasting and gel textural properties varied significantly between starches. Starch from orange-fleshed sweetpotatoes had lower pasting temperatures than starches from yellow/cream-fleshed genotypes, 72.2 ± 2.0 and 75.5 ± 1.1 °C, respectively. Notable inverse correlations were observed between the starch pasting temperature and perceived moistness (r = -0.63) and fibrousness (r = -0.70) of fries, whereas SPFF denseness was positively associated with starch pasting viscosity (r = 0.60) and nonstarch alcohol-insoluble solids content. Fry textures were likely affected by cooked starch properties, which should be considered when selecting varieties for sweetpotato fries. PRACTICAL APPLICATION: Without the aid of a batter, sweetpotato French fries (SPFFs) tend to be soft and limp-undesirable attributes in a fried food. The physiochemical properties of starch, the most abundant component in sweetpotato fries, were further explored in this study to better understand the properties of sweetpotato starch that influence SPFF textures. These findings can be used by sweetpotato processors and breeders for developing new sweetpotato varieties that are designed for production of fried products with desirable textures.}, number={5}, journal={JOURNAL OF FOOD SCIENCE}, author={Allan, Matthew C. and Marinos, Nicholas and Johanningsmeier, Suzanne D. and Sato, Ai and Truong, Van-Den}, year={2021}, month={May}, pages={1819–1834} }