Rate Of Starch Digestion Research Articles

Texture and Digestion Properties Based on Amylose Content and Gel Consistency in Landraces and Recently-Released Cultivars of Indica Rice in China

China has abundant rice landrace resources and has developed many new rice cultivars over the past several decades. To identify the differences in texture and digestion properties between landraces and recently-released cultivars of indica rice in China, this study estimated the hardness (Hd) and starch digestion rate (SDR) of cooked rice based on the amylose content (AC) and gel consistency (GC) of landraces and recently-released (2019–2021) cultivars of indica rice in eight provinces in southern China. The results demonstrated that AC ranged from 11.3% to 34.0% in landraces and from 10.0% to 28.6% in recently-released cultivars. The AC median was lower in recently-released cultivars than in landraces by approximately 40%. GC ranged from 21–100 mm in landraces and from 30–95 mm in recently-released cultivars. The GC median was about 130% higher in recently-released cultivars compared to landraces. Hd ranged from 720–1418 g in landraces and from 590–1244 g in recently-released cultivars. The Hd median was approximately 35% lower in recently-released cultivars compared to landraces. SDR ranged from 1.04–2.86 mg g min−1 in landraces and from 1.71–3.37 mg g min−1 in recently-released cultivars. The SDR median was higher in recently-released cultivars than in landraces by about 60%. The findings of this study suggest that recently-developed indica rice cultivars in China can cater to the preference of consumers for soft-texture rice but increase health risks due to a higher rate of digesting starch into glucose.

Effects of starch, protein structure change on quality of raw and cooked frozen oat roll

Oat roll is one of the traditional oat wholemeal foods, but it is easy to lose water and become firm during long time storage and transportation. There is no systematic study on the changes of oat rolls during the frozen storage. The aim of this study was to investigate the effects of frozen raw oat roll (FROR) and frozen cooked oat roll (FCOR). For the FROR and FCOR, the amylose leaching content increased significantly (p < 0.05) in frozen storage, the swelling power decreased significantly (p < 0.05), the order degree of protein secondary structure decreased. For the FROR, it has a higher digestion rate of starch, lower hardness after frozen storage, its retrogradation effect is not significant. For the FCOR, it has a lower digestion rate of starch, frozen storage can increase the gelatinization viscosity and starch retrogradation trend. The water loss rate was lower during frozen storage, but the larger ice crystals caused great damage to the internal structure. Overall, freezing has significant effect to the quality of oat rolls. The FROR has a better gelatinization characteristics and reheating hardness, the aging effect is not significant, and it became more digestible, so it can be used for oat roll food industrialization.

Identifying the shortfalls of crude protein-reduced, wheat-based broiler diets.

The objective of this review is to identify the shortfalls of wheat-based, crude protein (CP)-reduced diets for broiler chickens as wheat is inferior to maize in this context but to inconsistent extents. Inherent factors in wheat may be compromising gut integrity; these include soluble non-starch polysaccharides (NSP), amylase trypsin inhibitors (ATI) and gluten. Soluble NSP in wheat induce increased gut viscosities, which can lead to compromised gut integrity, which is not entirely ameliorated by NSP-degrading feed enzymes. Wheat ATI probably compromise gut integrity and may also have the capacity to increase endogenous amino acid flows and decrease apparent starch and protein digestibilities. Gluten inclusions of 20 g/kg in a maize-soy diet depressed weight gain and feed intake and higher gluten inclusions have been shown to activate inflammatory cytokine-related genes in broiler chickens. Further research is required, perhaps particularly in relation to wheat ATI. The protein content of wheat is typically higher than maize; importantly, this results in higher inclusions of non-bound amino acids in CP-reduced broiler diets. These higher inclusions could trigger post-enteral amino acid imbalances, leading to the deamination of surplus amino acids and the generation of ammonia (NH3) which, if not adequately detoxified, results in compromised growth performance from NH3 overload. Thus, alternatives to non-bound amino acids to meet amino acid requirements in birds offered CP-reduced, wheat-based diets merit evaluation. The digestion of wheat starch is more rapid than that of maize starch which may be a disadvantage as the provision of some slowly digestible starch in broiler diets may enhance performance. Alternatively, slowly digestible starch may result in more de novo lipogenesis. Therefore, it may prove instructive to evaluate CP-reduced diets based on maize-wheat and/or sorghum–wheat blends rather than entirely wheat. This would reduce non-bound amino acid inclusions by lowering dietary CP derived from feed grains and may enhance starch digestive dynamics by retarding starch digestion rates. Also, the use of biomarkers to monitor gut integrity in broiler chickens is examined where calprotectin, ovotransferrin and possibly citrulline appear to hold promise, but their validation requires further research.

Effect of storage conditions on the textural properties and in vitro digestibility of wheat bread containing whole quinoa flour

This research aimed to clarify the evolution of textural characteristics and in vitro digestibility under different storage conditions. Quickly increasing hardness and decreasing resilience was observed in quinoa bread after 5d cold (4 °C) storage. However, when stored at −18 °C for 5d, bread crumb still maintains a dense alveographic with 52.33% of cell density and 33.76% area fractions. In addition, the starch digestion rate decreased with increasing retrogradation degree. Scanning electron microscope (SEM) characterizations illustrated that the chunky matrix gradually disappeared with digestion. However, quinoa starch (QS) granules were the most difficult to digest owing to the relative intactness and wrapping in the protein-starch bulk. Meanwhile, X-ray diffraction (XRD) showed that the crystal structure of starch remained 21.09% stored in frozen conditions, and wheat type-A (WA) starch was mainly involved in gelatinization. The results of water migration proved that water participated in the retrogradation of starch and affected the quality of quinoa bread. Overall, bread stored in frozen conditions can maintain good texture characteristics and slow starch digestion rate. This study indicates that quinoa flour fortified bread has the potential to be developed as staple food with both low glycemic index values and storage stability.

Relations between in vitro starch digestibility of commercial baked products and their macronutrients.

Baked products such as biscuits and breads are the staple foods for a large population, with the starch digestion rate having a crucial effect on human health. Currently, there is a lack of information on general starch digestibility in commercial baked products and its correlation with macronutrient content. The present study investigated the starch digestibility of 35 commercial baked products, ranging from low to high moisture contents. Biscuits generally had a slower starch digestion rate than mini-breads, whereas breads including whole wheat bread had the fastest digestion rate. Additionally, starch digestibility was negatively correlated with the calorie (R2 =0.71) and fat content (R2 =0.56) in per serving size, possibly because of the formation of amylose-lipid complex. The present study provides a database for the in vitro starch digestibility of a large number of food items, which gives general indications on the performance of starch components of commercial products in the human gastrointestinal tract. © 2022 Society of Chemical Industry.

Properties and in vitro digestibility of a bread enriched with lentil flour at different leavening times

The effects of three leavening times (60, 105 and 150 min) on structure and some physico-chemical and nutritional properties of bread added with 20 % of green lentil flour were investigated. Leavening time largely affected bread physico-chemical properties, leading to a significant reduction in moisture content, an increase in weight loss and a darker appearance of bread crumb as leavening time increased. Besides, crumb of bread leavened for the longest time (B150) showed a compact structure and the highest resistance to the compression, while the Young’s modulus increased linearly with the rising of leavening time. By contrast, breads leavened for shorter times (B60 and B105) had a more porous structure with more circular bubbles compared to B150, exhibiting lower deformation resistance. Different bread macrostructure had a significant impact on the in vitro protein and starch digestibility. The α amino nitrogen release and the estimated Glycemic Index (eGI) at the end of digestion reached the lowest values in bread leavened for the longest time (B150). In particular, eGI showed a linear correlation both with the Young’s modulus (R 2 = −0.926) and macrostructural properties (R 2 = 0.902), suggesting that modelling bread structure by acting on leavening time can be a novel approach to develop healthier products. • Leavening time affected structure development of lentil flour (LF) enriched breads. • The glycaemic index was positively correlated to visual porosity of LF bread. • Bread visual porosity was negatively correlated to mechanical properties. • The released amino acids amount after digestion decreased at higher leavening times. • Leavening time could be used to modulate the rate of starch digestion.

Combined effects of starch fine molecular structures and water content on starch digestibility of cooked white rice

Although the starch digestibility of cooked white rice has been investigated with regard to its relation to starch structure, it is not yet clear how starch molecular structure and water content affect its digestion rate. To investigate this, the in vitro starch digestibility and molecular structure of 10 rice varieties with a range of rice-to-water cooking ratios were investigated. As expected, starch digestibility varied with different conditions. Typically, a higher amylose content resulted in a lower maximum digestion extent for a given water content. Having relatively more and longer amylopectin intermediate chains caused a slower starch digestion rate, but only with rice-to-water ratios between 1:1 and 1:1.2. These results could prove useful to find combinations of starch fine molecular structures and water contents to produce cooked rice with low glycemic index.

Whole grain rice: Updated understanding of starch digestibility and the regulation of glucose and lipid metabolism

Nowadays, resulting from disordered glucose and lipid metabolism, metabolic diseases (e.g., hyperglycemia, type 2 diabetes, and obesity) are among the most serious health issues facing humans worldwide. Increasing evidence has confirmed that dietary intervention (with healthy foods) is effective at regulating the metabolic syndrome. Whole grain rice (WGR) rich in dietary fiber and many bioactive compounds (e.g., γ-amino butyric acid, γ-oryzanol, and polyphenols) can not only inhibit starch digestion and prevent rapid increase in the blood glucose level, but also reduce oxidative stress and damage to the liver, thereby regulating glucose and lipid metabolism. The rate of starch digestion is directly related to the blood glucose level in the organism after WGR intake. Therefore, the effects of different factors (e.g., additives, cooking, germination, and physical treatments) on WGR starch digestibility are examined in this review. In addition, the mechanisms from human and animal experiments regarding the correlation between the intake of WGR or its products and the lowered blood glucose and lipid levels and the reduced incidence of diabetes and obesity are discussed. Moreover, information on developing WGR products with the health benefits is provided.

Using buckwheat starch to produce slowly digestible biscuits with good palatability

AbstractBackground and ObjectiveDue to the rapid digestibility, cooked starch can cause a high postprandial blood glucose response (hyperglycemia), one of the risk factors for metabolic diseases, such as obesity and diabetes. The objective was to understand the properties of starch that provided slow digestibility in low‐moisture baked goods. Buckwheat (Fagopyrum esculentum Moench) starch was used to prepare biscuits with slowly digestible starch and was compared with wheat (Triticum aestivum) starch.FindingsBuckwheat starch had higher gelatinization temperature and smaller breakdown viscosity (in pasting curve) than wheat starch. Slower starch digestion rate and higher amount of undigested starch were observed when 60% (w/w) wheat flour in biscuits was substituted by buckwheat starch than by wheat starch. The biscuits containing buckwheat starch or wheat starch also showed a structure with lower firmness than the control biscuits.ConclusionBuckwheat starch was more resistant to gelatinization and breakage during baking, and thus was less susceptible to enzyme digestion in biscuits than wheat starch.Significance and NoveltyThis is the first study utilizing a starch having a normal amylose content without any modification, except partial gelatinization during baking, as a source of slowly digestible starch in biscuits. Buckwheat starch not only provided slow digestibility, but also improved the palatability of the biscuits, creating a smoother and less firm texture than those made using whole grain flour.

Novel Methods to Evaluate Functional Saliva Characteristics Related to Food Perception

ObjectivesSaliva is the first digestive fluid that food encounters, and likely influences oral sensations and gastrointestinal processing of food. Yet, the pandemic drastically altered risks associated with saliva analysis. Thus, we developed novel functional assays to assess saliva remotely. We aimed for assays that could be self-administered by participants and that would reflect functional characteristics (emulsion stability, starch digestion) of saliva.MethodsTwo assays were developed: stability of oil/water emulsions created with saliva, and digestion of starch by salivary amylase. In the saliva emulsion assay, 7.5 mL of water with 1% purple food color and 7.5 mL of vegetable oil were provided to participants. Participants swished the oil/water mixture for 30 s and expectorated. The expectorates were analyzed for emulsion stability (size of “cream” layer). This stability was compared with dietary intake of fat and sensory ratings of fatty acids. In the salivary amylase assay, saliva was collected by chewing wax for 30 s. Saliva was then mixed with a starch-thickened commercial pudding. The flow of pudding/saliva mixture through a 10 mL syringe was measured from 2–8 min after mixing. The flow rates are being compared to dietary intake of starch and sensory perception of starchy foods.ResultsIn the saliva emulsion assay, greater emulsion stability corresponded to more intense sensation for fatty acids, indicating smaller, more stable droplets cause greater fat taste sensation. In the salivary amylase pudding assay, analysis indicates wide variability in rate of starch digestion. Some participants’ saliva/pudding mixtures emptied almost completely from the syringe at 2 min, while others had almost no flow through the syringe after 8 min of digestion. Analyses of how the digestion rates compare to dietary starch and sensory perception is ongoing.ConclusionsThese relatively simple assays for saliva function could be useful in future studies aiming to understand how oral digestion influences sensory properties of food, such as thickness or fattiness. Additionally, relating dietary habits to these salivary characteristics may help understand how behavior could influence these functional aspects of saliva.Funding SourcesNIDCD R21DC017559, USDA Hatch Project 1,013,624.

Manipulating the Microstructure of Potatoes for Slow Starch Digestion

ObjectivesPotatoes are nutritious foods that provide essential energy in the form of starch. However, numerous studies have shown that their consumption could lead to high postprandial glycemia. Our aim is to transform staple foods into a healthy diet with modulated postprandial glycaemia and sustained energy.MethodsPotatoes were blanched in a 500 ppm calcium solution for 30 min at 70 °C prior to streaming. We wanted to study if blanching potatoes in the presence of divalent cations increased pectin-cross linking and could lead to a lower cell wall permeability to digestive amylolytic enzymes. Potatoes were submitted to in-vitro simulated gastrointestinal digestion. The digestion of starch occurred in the intestinal phase in the presence of digestive enzymes (1350 U of pancreatic amylase, 3500 U of glucoamylase and 200 U of invertase). Aliquots were obtained at time intervals to quantify glucose release. The diffusivity rate of dextran probes (20 KDa, 60 KDa, and 150 KDa) into isolated potato cells was determined by the fluorescence recovery after photobleaching (FRAP) assay. Texture profile analysis (TPA) was also carried out to quantify multiple textural parameters.ResultsOur treatment increased the slowly digestible starch fraction of potatoes from 10.5% to 35.3%. Treated potatoes had 40.7% and 99.9% lower cell wall diffusivity of 20 KDa dextrans and 70 KDa dextrans, respectively. These results show that a-amylase (∼59 KDa) access to starch within the cells was significantly lower in our treated potatoes. Thus, is the driving factor for the slower starch digestibility rate. These results are unexpected since a-glucosidase is the gatekeeper for starch hydrolysis. Texture analysis showed that treated potatoes possess desirable attributes such as higher hardness which could drive consumer preference.ConclusionsDeveloping slowly digestible staple foods, such as potatoes, is a promising approach for moderating glycemia as well as extending satiation and energy, and, in the long-term, control food intake and bodyweight.Funding SourcesThis research was funded by A*STAR Biomedical Research Council grant IAF-PP (HBMS Domain): Food Structure Engineering for Nutrition and Health.

P45. The effect of processing on in vitro starch digestion rate of cereal grains depends on species

P45. The effect of processing on in vitro starch digestion rate of cereal grains depends on species

Starch retrogradation in potato cells: Structure and in vitro digestion paradigm

The consumption of foods with intact cellular structure is recognized to lower the glycemic index. Studies have focused on the gelatinization and digestibility of starch in intact cells. However, the effects of intact cells on starch retrogradation and digestibility are still unclear. Mild acid and alkali soaking were used to isolate intact potato cells and hydrothermal treatment (73 °C for 30 min) followed by retrogradation (4 °C for 0–15 days). The retrogradation period of 0–15 days increased the crystallinity and enthalpy change, while decreased the digestion rate and extent in potato cell and starch ghost samples. Furthermore, the existence of cell wall (potato cell) lowered the starch digestion rate and extent than potato starch ghost. It was concluded that the ghost structure is the main factor that controls the starch retrogradation, whereas the intact cell wall structure provides the barrier for starch digestion and protects the ghost structure.

Impact of chia seed mucilage on technological, sensory, and in vitro digestibility properties of a texture-modified puree

• MS puree was less accepted than CSM regarding oral adhesiveness. • CSM puree showed the highest consistency and viscosity during oral processing. • CSM showed good technological and digestibility features to be used as thickener. • CSM could be used as alternative thickener in dysphagia-oriented foods. The impact of adding chia seed mucilage (CSM) as alternative to common thickeners, such as modified starch (MS), in a texture-modified chicken and vegetables puree and their effect on technological, sensory, and in vitro digestibility properties were evaluated and compared. The thickened purees showed weak gel behaviour with good oral consistency, but MS puree was less accepted than CSM regarding the oral adhesiveness. CSM purees presented the highest consistency and viscosity during the oral processing, which would facilitate a safe swallowing process. Its flow behaviour was scarcely affected by the conditions of simulated oral and gastric phases. Protein digestibility was not compromised, whereas the digestion rate of starch in CSM was lower than that of MS. These results demonstrate the feasibility of tailoring the technological, sensory, and digestibility properties of purees by adding different thickeners, and the suitability of CSM to be used in dysphagia-oriented products.

Fucoidan Regulates Starch Digestion: In Vitro and Mechanistic Study.

Bread is a high glycemic index (GI) food with high amounts of readily digestible carbohydrates. Fucoidan refers to a group of sulfated polysaccharides isolated from brown seaweed that has been gaining traction for its many functional properties, including its ability to inhibit starch hydrolases. In this study, fucoidan was added into bread to lower the glycemic index of bread. Fucoidan fortification at 3.0% reduced the starch digestion rate of baked bread by 21.5% as compared to control baked bread. This translated to a 17.7% reduction in the predicted GI (pGI) with 3.0% of fucoidan. Fucoidan was retained in the bread after baking. Although the in vitro bioavailability of fucoidan was negligible, the in vitro bioaccessibility of fucoidan was high, at 77.1–79.8%. This suggested that although fucoidan may not be absorbed via passive diffusion, there is potential for the fucoidan to be absorbed via other modes of absorption. Thus, there is a potential for the use of fucoidan as a functional ingredient in bread to reduce the glycemic potential of bread.

Effect of Extrusion and Konjac Flour Addition on the Antioxidant Activity, Structural Properties, and In vitro Digestibility of Extruded Oat–Corn Flour

AbstractOat–corn extruded powder is prepared to explore the effect of co‐extrusion with konjac flour on the structural properties and functional properties of the mixed powder for a reduced starch digestion rate. Scanning electron microscopy (SEM), X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FT‐IR), antioxidant activity, and in vitro digestibility are applied for analysis. SEM images after extrusion treatment show irregularity of the surface with some cracks and grooves. XRD and FT‐IR results show that the A‐type crystal structure disappears after extrusion, and the in vitro digestibility is improved but not significantly (p &gt; 0.05). After different amounts of konjac flour and oat and corn mixed powder are added for co‐extrusion, the surface microstructure is relatively rough, the pores of the mixed system are reduced, the crystal form is V‐shaped. The starch digestion rate is significantly decreased (p &lt; 0.05). The mixed powder with the addition of 5–15% konjac flour is a low GI material. It can be used as a raw material for meal replacement products.

Green preparation of holocellulose nanocrystals from burdock and their inhibitory effects against α-amylase and α-glucosidase.

In this work, holocellulose nanocrystals (hCNCs) were isolated from burdock insoluble dietary fiber (IDF) by enzymatic hydrolysis and ultrasonic treatment and their inhibitory effects against α-amylase and α-glucosidase were investigated. The hydrodynamic diameter of hCNCs decreased from about 600 to 200 nm with increasing sonication time, accompanied by an improvement in cellulose and glucose contents. Steady-state fluorescence studies suggested that static complexes were formed between hCNCs and α-amylase or α-glucosidase via a spontaneous and endothermic approach, which was driven by both hydrophobic interactions and hydrogen bonding. The median inhibitory concentration (IC50) values of hCNCs against the tested enzymes were positively correlated with their size, and non-competitive and mixed types of inhibition were detected using the Lineweaver-Burk plots. During the simulated digestion, the inclusion of burdock hCNCs obviously retarded the starch hydrolysis in both dose- and size-dependent manners, suggesting their potential in blocking the postprandial serum glucose upsurge.

Evaluation of cooking, nutritional, and quality characteristics of fresh-cut potato slice pretreated with acetic acid.

Fresh-cut potato slices are very popular in the service of hot-pots. However, the gelatinized starch easily escaping from the potato cells during cooking causes the thickening of beef tallow or soup in the hot-pot. Thus, acetic acid is considered for solving the problem of potato slices. Besides, the nutritional and quality characteristics of potato slices are also evaluated in this study. Results show that 1.0%-1.5% (v/v) acetic acid treatment can decrease mass loss and starch digestion rate, and delay the degradation of ascorbic acid and deterioration of color and texture of potato slices. Such treatment also inhibits membrane oxidation and PPO activity, and increase the total phenolic accumulation of potato slice in 7-day storage. The cell wall integrity of the potato slice is strengthened by acetic acid treatment, providing a strategy for the improvement of the boiling resistance of potato slice, and endowing potato slice with the digesting resistance. PRACTICAL APPLICATION: Acid pretreatment would cause the intensification of potato cell wall, which finally decrease the in vitro digestibility through decrease of leakage of gelatinized starch from potato cell and the contact between gelatinized starch and digesting enzyme. This observation proved that the integrity of cell structure in vegetable is important for their processing quality improvement (especially for their hardness improvement after heating or fermentation).

Inhibitory Effect of Ascorbic Acid on in vitro Enzymatic Digestion of Raw and Cooked Starches.

Ascorbic acid, also known as vitamin C, was previously reported to inhibit the activity of pancreatic α-amylase, the primary digestive enzyme for starch. A major implication of such inhibition is a slowed rate of starch digestion into glucose, which thereby reduces postprandial hyperglycemia. The aim of this study was to explore the inhibitory effects of ascorbic acid at various concentrations on the in vitro digestion of high amylose maize starch (HAMS) and potato starch (PS) in both raw and cooked conditions. Resistant starch (RS) content, defined as the starch that remained after 4 h of simulated in vitro enzymatic digestion, was measured for the starch samples. Upon the addition of ascorbic acid, the RS contents increased in both raw and cooked starches. Cooking significantly reduced the RS contents as compared to raw starches, and less increase in RS was observed with the addition of ascorbic acid. The inhibitory effect of ascorbic acid on the digestion of raw starches showed a dose-dependent trend until it reached the maximum extent of inhibition. At the concentrations of 12.5 and 18.75 mg/mL, ascorbic acid exhibited the most potent inhibitory effect on the in vitro starch digestion in raw and cooked conditions, respectively. Overall, our results strongly indicate that ascorbic acid may function as a glycemic modulatory agent beyond other important functions, and its effects persist upon cooking with certain concentrations applied.

Evaluation of dietary crude protein concentrations, fishmeal, and sorghum inclusions in broiler chickens offered wheat-based diet via Box-Behnken response surface design.

The objective of this study was to investigate the impacts of dietary crude protein (CP), fishmeal and sorghum on nutrient utilisation, digestibility coefficients and disappearance rates of starch and protein, amino acid concentrations in systemic plasma and their relevance to growth performance of broiler chickens using the Box-Behnken response surface design. The design consisted of three factors at three levels including dietary CP (190, 210, 230 g/kg), fishmeal (0, 50, 100 g/kg), and sorghum (0, 150, 300 g/kg). A total of 390 male, off-sex Ross 308 chicks were offered experimental diets from 14 to 35 days post-hatch. Growth performance, nutrient utilisation, starch and protein digestibilities and plasma free amino acids were determined. Dietary CP had a negative linear impact on weight gain where the transition from 230 to 190 g/kg CP increased weight gain by 9.43% (1835 versus 2008 g/bird, P = 0.006). Moreover, dietary CP linearly depressed feed intake (r = -0.486. P < 0.001). Fishmeal inclusions had negative linear impacts on weight gain (r = -0.751, P < 0.001) and feed intake (r = -0.495, P < 0.001). There was an interaction between dietary CP and fishmeal for FCR. However, growth performance was not influenced by dietary inclusions of sorghum. Total plasma amino acid concentrations were negatively related to weight gain (r = -0.519, P < 0.0001). The dietary transition from 0 to 100 g/kg fishmeal increased total amino acid concentrations in systemic plasma by 35% (771 versus 1037 μg/mL, P < 0.001). It may be deduced that optimal weight gain (2157 g/bird), optimal feed intake (3330 g/bird) and minimal FCR (1.544) were found in birds offered 190 g/kg CP diets without fishmeal inclusion, irrespective of sorghum inclusions. Both fishmeal and sorghum inclusions did not alter protein and starch digestion rate in broiler chickens; however, moderate reductions in dietary CP could advantage broiler growth performance.