Degree Of Gelatinization Research Articles

Impact of rehydration on multi-scale structural transformations and starch digestibility of dried noodles.

To understand the relationship between the structure and starch digestibility of dried noodles, the changes in multi-scale structure and in vitro starch digestibility of dried noodles with different protein contents (ranging from 10% to 15%) during rehydration were tracked. The results indicated that the hardness of dried noodles decayed according to the first-order exponential decay function, with rapid and slow stages. This depended on near-linear protein aggregation and near-logarithmic starch gelatinization. The gelatinization degree reached 70.9 to 79.4% in the early stage of rehydration. Water absorption kinetics and distribution analysis revealed that the moisture migrating into the noodles was initially utilized for starch gelatinization. This led to the formation of a honeycomb gel structure at the edge of the noodles, which gradually spread from the edge to the center, as observed by SEM and CLSM. As rehydration progressed, the starch digestion degree increased. The digestion rate (k1) decreased with the formation of the composite gel structure, while k2 showed an increased trend. Additionally, with the increase in the protein content of noodles, the aggregation degree and increment were enhanced. This resulted in the formation of a more compact composite gel structure, which reduced the rate and extent of starch digestion within the noodles. When the noodles were overcooked, the C∞ of the high-protein samples was reduced by approximately 10% compared to that of the low-protein samples. Overall, the formation of the composite gel structure reduces the heterogeneity of the noodles from the edge to the center, resulting in a closer starch digestion rate in fast and slow steps. Besides, the rapid and massive aggregation of proteins at high protein content contributed to the formation of a compact gel structure, which in turn interfered with the rate and extent of starch digestion.

Enhancement of the quality and in vitro starch digestibility of fried-free instant noodles with rapid rehydration using sourdough fermented with exopolysaccharide-producing Weissella confusa

This study aimed to enhance the rehydration property of fried-free instant noodles using a fermentation method with exopolysaccharide-producing Weissella confusa, thereby improving their quality. The effect of sourdough fermented with W. confusa on the rehydration property, cooking qualities and in vitro starch digestibility of fried-free instant noodles was investigated. Compared with the control group, the rehydration time of fried-free instant noodles prepared using W. confusa–fermented sourdough supplemented with 2 % sucrose was significantly reduced by 17.36 % from 403 to 333 s, the cooking loss was significantly decreased by 12.72 % from 12.50 % to 10.91 %, and the digestible starch content was significantly increased by 5.40 % from 73.09 % to 77.04 % (p < 0.05). Sourdough fermentation with W. confusa created an acidic environment and produced hydrophilic exopolysaccharides, which significantly enhanced the rehydration property and cooking quality of fried-free instant noodles by improving their degree of gelatinization and reducing their relative crystallinity (p < 0.05).

Effects of the hot air roasting process on brown rice moisturized by water–spraying method

The hard texture of brown rice, attributed to its bran layer, poses significant challenges in improving its palatability. This study investigated the effects of hot–air roasting on the morphological characteristics, thermal properties, and water absorption of brown rice, moisturized using a water–spraying method to enhance texture. Moisture–controlled roasting resulted in a significant difference in the L* values, with the highest observed at 20 % water content. The extent of cracking and fine fissure formation varied with roasting temperature, resulting in increased water absorption. These structural changes subsequently influenced the tan δ value, hardness, and stickiness in the rheological analysis post–cooking. The gelatinization degree significantly increased with higher roasting temperatures and retrogradation effects were noted at 130 °C and 150 °C with a 15 % water content during cooking. Texture and sensory evaluations confirmed an increase in hardness as retrogradation progressed. The observed changes in this study have a profound impact on the textural and sensory attributes of the final cooked product.

Thermal stability and in vitro digestive behavior of Pickering emulsion stabilized by high-amylose starch nanocrystals

In this study, high-amylose starch (HAS) was processed using sulfuric acid-ultrasonic cross-linking to produce high-amylose starch nanocrystals (HASNC). These nanocrystals were used to stabilize Pickering emulsions and assess their effectiveness in encapsulating β-carotene. Normal starch nanocrystals (NSNC) were prepared similarly for comparison. The HASNC retained key HAS properties, such as heat and enzyme resistance, providing several advantages to HASNC-stabilized emulsions. First, after exposure to 100 °C heat and in vitro tests simulating the mouth and stomach, the HASNC-stabilized emulsions demonstrated significantly greater stability and higher β-carotene retention compared to the NSNC-stabilized emulsions. This enhanced stability is attributed to the lower gelatinization degree and increased resistance to α-amylase hydrolysis of HASNC, which provides stronger steric stabilization of the oil droplets. Second, during in vitro small intestine tests, the greater enzyme resistance of HASNC allowed for the formation of a denser barrier around the oil droplets, effectively preventing lipase and bile salts from contacting the oil droplets. This led to a reduced rate and extent of lipid digestion and facilitated a sustained-release effect. Consequently, HASNC, as a starch-based emulsifier, show great potential as an effective delivery system for the sustained release of bioactive compounds.

Enhancing the Health and Lifespan of Honey Bees (Apis mellifera L.) with an Innovative Soybean-Based Diet Supplemented with Porcine Blood1

Abstract This study investigated the effect of soy-based diets supplemented with porcine blood (PB) on the diet's external morphology, nutritional efficacy, and health impacts on honey bees, Apis mellifera L. (Hymenoptera: Apidae). Scanning electron microscopy revealed that the control diet (maize bee bread) displayed ruptured granules with small particles, whereas the soy-based diets showed varying degrees of protein gelatinization and aggregation depending on the presence of PB. Nutritional analysis indicated that maize bee bread was used as a positive control contained 12.2% protein and provided 312.89 kcal/100 g, whereas the formulated soy-based diets with skim milk or PB showed 13–15% protein, meeting the required needs for optimal honey bee health and development. Survival and longevity assessments showed no significant difference in lifespan between honey bees fed with artificial diets and the control, but all treatment groups outlived the negative control, which fed only on syrup. Moreover, the diameter of the hypopharyngeal gland acini, a key indicator of the nutritional state and health in honey bees, was significantly larger in honey bees fed protein-enriched diets compared with those receiving only syrup. These findings underscore the potential of soy-based artificial protein diets, especially when enhanced with PB, to support honey bee health and longevity, comparable with natural pollen sources.

Insight into the relationship between the starch crystalline structure and textural quality and physicochemical properties of reconstituted rice: Influence of feed moisture content

Reconstituted rice was prepared by extrusion with different feed moistures (30 %, 33 %, 36 %, 39 % and 42 %), and the relationship between the crystalline structure, physicochemical properties, and textual quality of reconstituted rice was studied. The results revealed that, with the feed moisture increased (33 %–36 %), the gelatinization degree reached 97.28 % and the bound water content increased by 23.58 %. The water absorption index and swelling power index reached 8.35 g/g and 9.46 g/g, respectively, and the texture properties were close to those of native rice. Higher extrusion feed moisture (39 %–42 %) increased the setback value (206.00 cP) and breakdown value (721.33 cP) of starch, and the hardness and gumminess of reconstituted rice were also increased (p < 0.05). The starch crystalline structure was disrupted by extrusion and changed to a surface fractal structure, the relative crystallinity decreased from 26.87 % to 6.68 %, and the degree of order decreased from 1.680 to 1.006. Correlation analysis revealed that the crystalline structure of starch and water distribution would affect the textural and hydration properties of reconstituted rice. The results provide theoretical references and data support for improving the edibility and quality of reconstituted rice and enhancing the utilization rate of broken rice.

Impact of the degree of starch gelatinization on the texture, soaking, and cooking characteristics of high amylose rice: an experimental and numerical study

Impact of the degree of starch gelatinization on the texture, soaking, and cooking characteristics of high amylose rice: an experimental and numerical study

Effect of soaking conditions on physicochemical properties and sensory quality of cooked glutinous rice with an electric rice cooker

This research aimed to investigate the changes in physicochemical properties and sensory qualities of cooked glutinous rice (RD6) by using the electric rice cooker method with different soaking conditions compared to cooking glutinous rice by steaming in a conventional steamer (control). Glutinous rice grain was soaked at different soaking conditions of temperatures at 25 and 45°C and soaking time for 30, 60, and 90 min, and then were cooked by the electric rice cooker. The results indicated that the degree of starch gelatinization was increasingly correlated with the moisture content and water activity of the cooked waxy rice. Moreover, with the increase in the degree of gelatinization, the hardness value exhibited a decreasing trend, and the adhesiveness value increased. The L* (lightness), a* (redness), and whiteness index of cooked glutinous rice increased when the temperature and time of soaking increased, while the color intensity decreased. The overall acceptability scores indicated that the lower soaking time obtained a higher score for cooked glutinous rice. Compared with the control sample, the soaking conditions for the temperature and time of 25°C/30 min or 45°C/30 min are viewed as a suitable ratio of a good quality product for cooked glutinous rice by using the electric rice cooker method, in which rice cooking provided the high score of overall acceptability on consumer preference.

Effect of soaking conditions on physicochemical properties and sensory quality of cooked glutinous rice with an electric rice cooker

This research aimed to investigate the changes in physicochemical properties and sensory qualities of cooked glutinous rice (RD6) by using the electric rice cooker method with different soaking conditions compared to cooking glutinous rice by steaming in a conventional steamer (control). Glutinous rice grain was soaked at different soaking conditions of temperatures at 25 and 45°C and soaking time for 30, 60, and 90 min, and then were cooked by the electric rice cooker. The results indicated that the degree of starch gelatinization was increasingly correlated with the moisture content and water activity of the cooked waxy rice. Moreover, with the increase in the degree of gelatinization, the hardness value exhibited a decreasing trend, and the adhesiveness value increased. The L* (lightness), a* (redness), and whiteness index of cooked glutinous rice increased when the temperature and time of soaking increased, while the color intensity decreased. The overall acceptability scores indicated that the lower soaking time obtained a higher score for cooked glutinous rice. Compared with the control sample, the soaking conditions for the temperature and time of 25°C/30 min or 45°C/30 min are viewed as a suitable ratio of a good quality product for cooked glutinous rice by using the electric rice cooker method, in which rice cooking provided the high score of overall acceptability on consumer preference.

Effect of heating treatment on processing characteristics of rice dough

Rice dough is a good source of digestible protein due to its advantages of being gluten-free and hypoallergenic compared to wheat dough, but the poor elasticity, low elongation and adhesion of rice dough limit its application. The effect of heating treatment with different temperature (40–100 °C) on processing characteristics of rice dough was explored. The results of fermentation characteristics showed that the best gas production and gas retention properties of rice dough were achieved at 70 °C. The rheological properties demonstrated a certain degree of deformation resistance at 85 °C, which resulted in the rice dough system exhibiting a tendency to flow at this temperature. Consequently, the blanching dough below 85 °C was deemed preferable for blanching. In addition, with the increase of temperature during blanching., the strength of the rice dough gel network increased. The results of proton distribution showed some of the emi-bound and free water in the rice dough was bound to bound water by exposed hydroxyl groups, leading to an increased bound water content, a decreased adsorbed and free water content. The degree of gelatinization of the rice dough increased gradually with increased blanching temperature, and the stability and resilience of rice dough reached the best at 70 °C. The thermal stability demonstrated that the ungelatinized portion of the rice dough exhibited enhanced structural stability, with the optimal thermal stability attained at 70 °C. It can therefore be concluded that the scalded dough made at 70 °C exhibits superior performance in all aspects and is suitable for subsequent processing of rice dough, which suggests a novel approach to the utilisation of rice dough in the future.

Kinetics of chemical and color changes in wheat and water during atmospheric cooking as affected by the acidity, hardness, and iron content of water.

Color changes in wheat and cooking water, which affect the quality of bulgur and wastewater, are important. Understanding the impacts of cooking water acidity, hardness, and iron content is significant for producing bright-yellow colored bulgur and determining the possible negative effects of cooking water on the environment. Thereby, the gelatinization degree and color (L*, a*, b*, and yellowness index) of wheat cooked with waters at different pH (3, 5, 7, 9, and 11), hardness (soft, hard, and very hard), and iron content (0, 1, and 2mg/L) were determined every 10min of cooking. pH, Brix, conductivity, hardness, turbidity, and color of cooking waters were also determined and kinetically modeled. After cooking, it was revealed that cooking with water at pH 3 favored the color of cooked wheat, whereas pH 11 caused darkening. Nevertheless, as the wastewater pH of cooking waters with pH 3 and 11 may be harmful to the environment, it is recommended to use water in the range of pH 5-9 for bulgur production. Cooking with very hard water is also not recommended as it causes some adverse effects such as diminishing the gelatinization rate in wheat, increasing the cooking time, and negatively affecting the color.

Characteristics Of Partially Pregelatinized Sago Starch Extruded Under Various Conditions Using A Twin Screw Extruder Without A Die

Abstract This study aims to obtain the characteristics of PPSS as a binder extruded in a twin-screw extruder (TSE) without a die under 9 extrusion conditions selected from a systematic review. The Successive conditions: moisture content, last zone of barrel temperature, and screw speed for each condition were recorded. Respectively, the values were 32%, 60⁰C, 100 rpm for PPSS 1; 22%; 120⁰C; 250 rpm for PPSS 2; 22%, 100⁰C, 250 rpm for PPSS 3; 16%, 135⁰C, 150 rpm for PPSS 4; 10%, 160⁰C, 200 rpm for PPSS 5; 28.8%;, 100⁰C, 220 rpm for PPSS 6; 30%, 80⁰C, 200 rpm for PPSS 7; 25.2%, 97.5⁰C, 250 rpm for PPSS 8, and 30%; 135⁰C; 160 rpm for PPSS 9. The study informed that the degree of gelatinization (DG), water solubility index (WSI), water absorption index (WAI), and swelling power (SP) of PPSS 6 were the highest among the others but its bulk density (BD), degree of whiteness (DW), maximum viscosity (MV), and enthalpy were the lowest. Scanning electron microscopy showed that PPSS granules were irregular compared to their natural oval shape. Starch granule crystallinity indicated that some crystallines became amorphous and some increased (PPSS 3 and 4) while birefringence properties almost disappeared entirely.

The Effect of Sodium Tripolyphosphate and Guar Gum on Physical Characteristics of Analog Rice from Gaplek Flour

Gaplek flour is a processed product of cassava preservation abundant during the harvest season in Lampung Province. The high carbohydrate content in cassava facilitates the processing of gaplek flour into carbohydraterich food source, such as analog rice. Therefore, this study aimed to investigate the effect of adding STPP and guar gum on the formulation of analog rice made from 70% gaplek flour and 30% corn flour. Analog rice was produced using the extrusion method with a twin-screw extruder. The results showed that the addition of STPP did not affect water absorption characteristics. The solubility of rice in deep water also decreased with increasing amounts of STPP and guar gum. Meanwhile, guar gum significantly increased water absorption and reduced the solubility of rice in water. The degree of gelatinization decreased with the addition of both materials. The addition of 0.3-0.5% STPP and 0.5-2% guar gum had no significant effect on hardness, stickiness, elasticity, and cohesiveness of analog rice prepared using a cooker.

Micronization induced gelatinization of tapioca starch and its effects on starch physicochemical and structural properties.

The vibrating superfine mill (VSM) is a machine that belongs to the micronization technique. In this study, VSM was employed to produce micronized tapioca starch by varying micronization times (15, 30, 45, and 60min). The structural and physicochemical properties of the micronized starch were then examined. Scanning electron microscopy studies revealed that micronized starch was partially gelatinized, and the granule size dramatically increased when micronization time increased. X-ray diffraction patterns showed that the relative crystallinity was decreased from 24.67% (native) to 4.13% after micronization treatment for 15min and slightly decreased after that. The solubility of micronized starch significantly increased as the micronization time increased, which was associated with the destruction of the starch crystalline structure. Differential scanning calorimetry investigations confirmed that micronized starch was "partly gelatinized," and the degree of gelatinization increased to 81.27% when the micronization time was 60min. The weight-average molar mass was reduced by 15.0% (15min), 30.9% (30min), 55.7% (45min), and 70.5% (60min), respectively, indicating that the molecular structure was seriously degraded. The results demonstrated that the physicochemical changes of micronized starch granules were related to the destruction of the starch structure. These observations would provide details on micronized starch and its potential applications. PRACTICAL APPLICATION: These observations would provide details on micronized starch and its potential applications. Moreover, we believe that when the structures of starches were known, it is probable that the effect of VSM on the structural and physicochemical properties change of other starches might be predicted by adjusting the processing time.

Effects of feed conditioning temperature on pellet quality, growth performance, intestinal development and blood parameters of geese from 1 to 28 d of age

A 28-d experiment was conducted to investigate the effects of feed-conditioning temperature on the pellet quality, growth performance, intestinal development, and blood parameters of geese. A total of 180 one-day-old White Yuzhou goslings were randomly allotted to 5 treatment groups, with 6 replicates containing 6 birds each. Five diets were conditioned at 65, 70, 75, 80, and 85°C. Body weight and feed intake per pen basis were recorded from the arrival to the end of the trial. Blood and small intestine samples were collected on d 28 for analysis. The results showed that the pellet durability index (PDI), pellet hardness, and gelatinisation degree of starch (GDS) increased with increasing conditioning temperature (P < 0.05). The final body weight (FBW), average daily gain (ADG) and average daily feed intake (ADFI) of goslings significantly increased when conditioning temperature increased from 65 or 70°C to 80 or 85°C (P < 0.05), accompanied by unaffected feed conversion ratio (FCR) (P > 0.05). The villus height to crypt depth ratio (VH/CD) in the duodenum and ileum improved with increasing conditioning temperature (P < 0.05). Additionally, trypsin and amylase activity were enhanced when the conditioning temperature increased from 65 to 85°C (P < 0.05). No significant differences in the carcass traits and blood parameters of goslings were observed among the groups (P > 0.05). Overall, under the present experimental conditions, increasing the steam-conditioning temperature of pelleted feed improved pellet quality, growth performance, intestinal morphology, and digestive enzyme activity in goslings. Based on broken-line regression analysis, the lower critical conditioning temperature for ADG in geese from 1 to 28 d of age was 80.95°C.

Interactions between partially gelatinized starch and nonstarch components in potato flour and their performance in emulsification

To develop natural complex materials as starch-dominated emulsifiers, pregelatinization was conducted on potato flour. The effects of gelatinization degrees (GDs, 0 %–50 %) on the structural characteristics, physicochemical properties, and emulsifying potentials of potato flour were investigated. Increasing GD of potato flour promoted protein aggregation on starch granules surfaces and transformed starch semicrystalline structures into melted networks. The emulsion stabilized with 50 % GD potato flour exhibited excellent storage stability (7 d) and gel-like behavior. With increasing GD from 0 to 50 %, the respective apparent viscosities and elastic moduli of emulsion increased from 21.4 Pa to 1126.7 Pa, and from 0.133 Pa·s to 1176.6 Pa·s, promoting the formation of a stable network structure in the emulsion. Fourier transform infrared spectra from emulsions with a continuous phase of >20 % GD displayed a new peak around 1740 cm−1, suggesting improved covalent interactions between droplets, thereby facilitating emulsion stability. Confocal laser scanning microscopy images indicated that droplets could be anchored in the melted networks and broken starch granules, inhibiting droplets coalescence. These results suggest that pregelatinization is a viable strategy for customizing natural starch-dominated emulsions.

Quality Evaluation of Fermented Pre Gelatinized Unripe Plantain and Soybean Based Complementary Foods 1: Physicochemical, Sensory and Rheological Properties

Aims: This study aimed at evaluating the effect of the degree (%) of starch gelatinization (G) and fermentation (F) on the physicochemical characteristics of the flours and also the sensory and flow properties of the gruels of unripe plantain fruits and soybean seeds based complementary foods. Study Design: Completely randomized design Place and duration of the Study: This study was carried out in Makurdi, Benue State, Nigeria, between January and November 2023. Methodology: Plantain slices heated to obtain 10% to 100% starch gelatinization were subjected to accelerated natural fermentation followed by drying and milling to yield fermented (F) flours. Non-gelatinized (NG) and nonfermented (NF) lots served as controls. The flours were each combined with soybean flour to obtain 16 g protein/100 g of each mixture based on the proximate compositions of the inputs using material balancing technique. The flours’ oil absorption capacities (OAC), water absorption capacities (WAC), packed bulk densities (PBD), sensory attributes (taste, mouth feel, appearance, overall acceptability) and flow properties of their gruels were evaluated using standard methods. Significant differences and separation of the data means were achieved by Duncan multiple range and Turkey’s tests using an SPSS package, respectively. Results: Gelatinization and fermentation increased WAC and OAC, but decreased packed bulk density (PBD) of the flours with concomitant reduction in pH, viscosities and improved sensory attributes of the gruels. Generally, viscosities increased with increase in slurry concentration and decreased with increase in temperature and shear rates. The flow behavior indices ranged from 0.27 to 0.64, with lower values in gelatinized and fermented samples, showing more pseudoplastic behavior in pretreated samples. Conclusion: Gelatinization and natural fermentation are therefore adaptable technologies, especially at rural levels, to improve acceptability and bulk reduction of resistant starch-based complementary foods.

Impact of roasted oat flour on the gas cell structure of steamed oat cake and its underlying mechanism

Roasting (or called stir-frying) can modify the properties of oat flour and improve the poor quality of steamed oat cake, especially uneven gas cell and high hardness, but the underlying mechanism remains unclear. The properties of protein-starch network matrix of oat dough (made by roasted oat flours with gelatinization degrees of 30%, 50% 70% and 90%) before and after steaming were investigated, as well as the air/water interfacial characteristics of oat dough liquor. Results revealed that adding roasted oat flour with moderate gelatinization degree to the raw oat flour (ROF) could significantly improve the quality of steamed oat cakes, and their average pore size and specific volume reached the corresponded maximum values when roasted oat flour with gelatinization degree of 50% (G50) was added, which were 1.97 mm and 2.56 mL/g, respectively. Roasted oat flour with moderately gelatinization could not only facilitate the formation of protein polymers by promoting disulfide cross-linking of larger monomer proteins in both raw and steamed oat dough, but also induce the conversion of random coil to α-helix and β-sheets structure, resulting in an ordered protein secondary structure. Meanwhile, the improvement of short-range molecular order structure of starch in oat dough was observed for ROF/G50（w/w = 1:1）sample (RG50). Additionally, compared to ROF, RG50 sample possessed the strongest foaming stability, which increased from 32.70% to 61.43%. In conclusion, the quality enhancement of steamed oat cake can be attributed to the combined effects of changes in the protein-starch matrix and the thin liquid film induced by moderately roasted oat flour.

Hot air–assisted radio frequency drying of corn kernels: the effect on structure and functionality properties of corn starch

Hot air (HA) drying caused quality damage of grains with long treatment time. Radio frequency (RF) heating as an emerging technology was applied to improve drying quality of cereals effectively. The effects of HA-RF drying (50 °C, 70 °C, 90 °C) of corn kernels on the morphology, structure, and physicochemical properties of starch were investigated and compared with HA drying. The surface of treated starch became rough, along with fragments and pores. Drying treatments increased the amylose content from 10.59 % to 23.88 % and the residual protein content of starch from 0.58 % to 1.23 %, and reduced the crystallinity from 31.95 % to 17.15 % and short–range order structures of starch from 0.918 to 0.868. The change of structures in turn resulted in the increase of pasting viscosity, gelatinization temperature, storage modulus and loss modulus. Furthermore, the HA-RF dried starch displayed stronger thermal stability, higher gelatinization degree and better gelation properties than the HA-treated starch at the same temperature. The data proved that the synergistic effects of HA and RF were more effective in modulating the starch structure and improving the functional characteristics of corn starch. This paper would like to provide potential reference for better application of HA-RF technologies to corn.

Preparation and physicochemical properties: a new extruded rice using cassava starch and broken rice flour

With the increasing demand for nutrition and health, many researchers are trying to develop a rice product with lower aging rate and convenient nutrient fortification. Being composed of high amylopectin content, cassava starch (CS) shows a lower retrogradation tendency compared to rice starch. So, it has a broad application prospect to partially replace rice starch with CS in rice by extrusion technology. In this study, a new extruded rice (ER) was prepared by broken rice flour and CS using single-screw extruder through “improved extrusion cooking technology,” and the maximum addition level of CS in ER was 30%. Color parameters and texture profile analysis showed that ER was a little darker in appearance with lower hardness, adhesiveness and chewiness. Rapid visco analysis demonstrated that the viscosity of ER paste appeared earlier during the initial heating phase and displayed a lower retrogradation trend than normal rice in the cooling process. The gelatinization temperature and gelatinization enthalpy decreased with the increasing CS in ER, while the degree of gelatinization increased to 76.36% when the content of CS was 30% after extrusion. The X-ray diffraction patterns of control was typical A-type structure, while ER changed to V-type structure with a lower degree of crystallinity. The microstructure observation showed that ER exhibited a looser and more porous structure with increasing the content of CS, which facilitated easier cooking and nutritional enhancement.