The effect of various cooking methods on resistant starch content of foods

Effect of baking conditions on resistant starch: Model systems and cake formulations

Five ingredients rich in RS (resistant starch) were assessed in a model system simulating baking process (water addition 30-50%, 180 °C/35 min) and in reformulated cakes (50% replacement of wheat flour). Moreover, two enzymatic methods used for RS determination (official and rapid) were compared. The combined effect of heating and water addition (50%) significantly decreased the RS content in all ingredients. Reformulated vegan cakes presented significantly lower RS values than those theoretically expected, according to the RS value of raw ingredients. The highest RS amount was observed for Hi Maize, which kept 84% and 72% of the initial RS content in the model systems and cake, respectively. Only the cakes made with Hi Maize reached the criteria for the health claim related to the reduction of post-prandial glycemic response (European Union regulation). Finally, differences between the official and rapid methods were less significant in the cakes than in the model systems.

Effects of cooking methods on the physical properties and in vitro digestibility of starch isolated from Chinese yam

The objective of this study was to compare the structural and functional attributes of Chinese yam starches obtained via different domestic cooking methods. Cooking changed the crystalline type from the C type to the CB type, and disrupted the short- and long-range molecular order of Chinese yam starch. The average chain length of amylopectin in BOS (boiling starch) was the smallest at 22.78, while RWS had the longest average chain length, reaching 24.24. These alterations in molecular structure resulted in variations in functional properties such as solubility, swelling power (SP), pasting characteristics, and rheological properties. Among these alterations, boiling was the most effective method for increasing the water-binding capacity and SP of starch. Specifically, its water holding capacity was 2.12 times that of RWS. In vitro digestion experiments indicated that BOS has a higher digestion rate (k = 0.0272 min-1) and lower RDS (rapidly digestible starch), which may be related to its amylopectin chain length distribution. This study can guide us to utilize yam starch through suitable cooking methods, which is relevant for the processing and application of Chinese yam starch.

Analysis of glycans in a Burnt-on/Baked-on (BoBo) model food soil using Microarray Polymer Profiling (MAPP) and immunofluorescence microscopy

Burning of food materials during cooking can increase the difficulty in removal from solid surfaces, forming residual food soils. Using molecular probe-based technologies, the aim of this work was to elucidate the composition and relative abundance of glycans within a Burnt-On/Baked-On (BoBo) model food soil and investigate enzyme systems that may facilitate soil breakdown. Microarray Polymer Profiling identified xylan, arabinoxylan, mixed-linkage glucan and mannan as target substrates for the enzymatic cleaning of BoBo residues from surfaces. Indirect immunofluorescence microscopy revealed that burning resulted in extensive structural modifications and degradation of the three-dimensional architecture of constituent polysaccharide matrices. Results from high-throughput enzyme screening indicate that inclusion of xylan depolymerising enzymes in automatic dishwashing detergents may improve cleaning of recalcitrant, plant glycan-rich BoBo soils. Collectively, this study provides new insight into the composition and removal chemistry of complex, multi-component food soils.

Effect of autoclave-cooling cycles combined pullulanase on the physicochemical and structural properties of resistant starch from black Tartary buckwheat

A starch-rich portion is produced as a by-product of black Tartary buckwheat processing. The effect of enzymatic combined with autoclaving-cooling cycles (one, two, or three times) on the physicochemical and structural properties of black Tartary buckwheat type 3 resistant starch (BRS) was evaluated. The autoclaving-cooling cycles enhanced solubility and reduced swelling, with the BRS content increasing from 14.12% to 25.18%. The high crystallinity of the BRS reflected a high molecular order. However, increasing the number of autoclaving-cooling cycles did not result in higher BRS content. The highest BRS yield in the autoclaved starch samples was 25.18% after double-autoclaving-cooling cycles. Furthermore, the autoclaving-cooling cycles altered the crystalline structure of black Tartary buckwheat, and the subsequent crystallinity changed from 36.33% to 42.05% to 38.27%. Fourier-transform infrared spectroscopy shows that the number of cycles results in more efficient double-helical packing within the crystalline lamella. Principal component analysis showed that the autoclaving-cooling cycle treatment leads to significant changes in the molecular structure of resistant starch (RS). These results indicated that autoclaving-cooling cycles might be a feasible way for producing RS from black Tartary buckwheat starch with better structural stability to expand their application range.

Cooking Methods and Their Relationship with Anthropometrics and Cardiovascular Risk Factors among Older Spanish Adults

Food consumption has a prominent role in the occurrence of cardiometabolic diseases, however, little is known about the specific influence of cooking methods. This study examined the association between cooking methods and anthropometrics, cardiovascular risk factors, and cardiac damage biomarkers in older adults. Data were taken from 2476 individuals aged ≥65 from the Seniors-ENRICA 2 cohort in Spain and recruited between 2015 and 2017. Eight cooking methods (raw, boiling, roasting, pan-frying, frying, toasting, sautéing, and stewing) were assessed using a face-to-face validated dietary history. Study associations were summarized as adjusted percentage differences (PDs) in anthropometrics, cardiovascular risk factors, and cardiac damage biomarkers between extreme sex-specific quintiles ((5th − 1st/1st) × 100) of food consumed with each cooking method, estimated using marginal effects from generalized linear models. After adjusting for potential confounders, including diet quality, PDs corresponding to raw food consumption were −13.4% (p-trend: <0.001) for weight, −12.9% (p-trend: <0.001) for body mass index (BMI), −14.8% (p-trend: <0.001) for triglycerides, and −13.6% (p-trend: <0.115) for insulin. PDs for boiled food consumption were −13.3% (p-trend: <0.001) for weight, −10.0% (p-trend: <0.001) for BMI, and −20.5% (p-trend: <0.001) for insulin. PDs for roasted food consumption were −11.1 (p-trend: <0.001) for weight and −23.3% (p-trend: <0.001) for insulin. PDs for pan-fried food consumption were −18.7% (p-trend: <0.019) for insulin, −15.3% (p-trend: <0.094) for pro-B-type natriuretic peptide amino-terminal, and −10.9% (p-trend: <0.295) for troponin T. No relevant differences were observed for blood pressure nor for other cooking methods. Raw food consumption along with boiling, roasting, and pan-frying were associated with healthier cardiovascular profiles, mainly due to lower weight and insulin levels. Future experimental research should test the effectiveness of these cooking methods for cardiovascular prevention in older adults.

The Glycemic Index and Human Health with an Emphasis on Potatoes

Diabetes and obesity are associated with the excessive intake of high-glycemic index (GI) carbohydrates, increased glycemic load (GL) foods, and inactive lifestyles. Carbohydrate-rich diets affect blood glucose levels. GI is an indicator of the impact of a specific food on blood glucose, while GL represents the quantity and quality of carbohydrates in the overall diet and their interactions. There are in vitro and in vivo methods for estimating GI and GL. These values are useful human health markers for conditions such as diabetes, obesity, and pregnancy. Potato is a major starchy vegetable, which is consumed widely and is the fourth most important crop globally. However, the GI of diets rich in starchy vegetables such as potatoes has not been studied in detail. The GI values in potatoes are affected by external and internal factors, such as methods of cooking, methods of processing, resistant starches, cultivation methods, mixed meals and food additions, and hormone levels. This review summarizes how these factors affect the GI and GL associated with diets containing potatoes. Understanding the impacts of these factors will contribute to the development of new and improved potato varieties with low GI values. The consumption of low-GI foods will help to combat obesity. The development of low-GI potatoes may contribute to the development of meal plans for individuals living with diabetes and obesity.

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.

Impact of dietary intake of resistant starch on obesity and associated metabolic profiles in human: a systematic review of the literature

As a global public health issue with an increasing prevalence, obesity is related to several metabolic disorders, but is largely preventable. Resistant starch (RS), the indigestible portion of starch, has been studied for its potential effects on reducing obesity. This systematic review aimed to investigate the effect of dietary intake of RS on obesity development and related metabolic profiles in human, including body weight and composition, energy intake and satiety, lipid profiles, blood glucose and insulin, and other blood biomarkers. Eleven peer-reviewed articles published in English between 2000 and 2019 were identified after screening using CENTRAL, MEDLINE, and CINAHL Plus. Based on the results, RS intake had no direct effect on body weight and body composition. Evidence for its effect on reducing energy intake and increasing satiety, as well as improving lipid profiles was inconsistent. Beneficial effects of RS intake on several blood biomarkers were supported, indicating its regulatory roles in blood glucose homeostasis, insulin sensitivity, and gut hormone concentrations. Specifically, five out of the eight articles measuring blood glucose reported a decrease in either fasting or postprandial glucose levels; two out of the three articles measuring insulin sensitivity indicated a significant improvement after RS supplementation; studies measuring gut hormone concentrations including glucagon-like peptide 1 (GLP-1), and peptide YY (PYY) also showed significant improvements after RS interventions. In conclusion, the effect of dietary intake of RS on obesity and its related metabolic complications was not conclusive. Further research with larger sample sizes and longer duration is warranted.

Structural Basis of Resistant Starch (RS) in Bread: Natural and Commercial Alternatives

Bread is categorized as having a high amount of rapidly digested starch that may result in a rapid increase in postprandial blood glucose and, therefore, poor health outcomes. This is mostly the result of the complete gelatinization that starch undergoes during baking. The inclusion of resistant starch (RS) ingredients in bread formulas is gaining prominence, especially with the current positive health outcomes attributed to RS and the apparition of novel RS ingredients in the market. However, many RS ingredients contain RS structures that do not resist baking and, therefore, are not suitable to result in a meaningful RS increase in the final product. In this review, the structural factors for the resistance to digestion and hydrothermal processing of RS ingredients are reviewed, and the definition of each RS subtype is expanded to account for novel non-digestible structures recently reported. Moreover, the current in vitro digestion methods used to measure RS content are critically discussed with a view of highlighting the importance of having a harmonized method to determine the optimum RS type and inclusion levels for bread-making.

Development of an Expanded Snack of Rice Starch Enriched with Amaranth by Extrusion Process

This study aimed to obtain a second-generation snack by extrusion from the by-product of rice milling enriched with amaranth. The raw material used was amaranth flour (AF), rice starch (NS) and modified rice starch (MS), which were evaluated by the analysis of substitution degree (SD), differential scanning calorimetry (DSC), viscosity (RVA), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). The snacks were expanded by extrusion and microwave oven, as a reference method. The samples were evaluated in hardness (D), expansion index (EI), apparent density (DAP), and protein content (P). Afterward, the optimized samples were evaluated by scanning electron microscopy (SEM) and resistant starch (RS). During the thermal characterization, a clear trend in the decrement in gelatinization temperatures was observed (78.35 to 63.90 °C in NS and MS respectively). The curves obtained in RVA analyses showed typical behavior of native (6.35 Pa.s) and extruded starches (2.88 Pa.s), with a significant decrease in viscosity peak. Through the analysis of FT-IR, the introduction of the functional acetyl group (stretching at a wavelength of 1735 cm⁻¹) was corroborated. Snack samples results showed a maximum hardness in MS, with a value of 121 N, and the NS (100%) presented the highest EI value (1.41). The lowest DAP values were obtained for the MS (0.48 g/cm³, 100%) and AF (0.49 g/cm³, 100%) samples. P increased to a higher concentration of AF. In the optimum formulation, the SEM image showed that the expanded microwave sample increased the porosity and obtained an RS value of 8.2%. The formulation obtained in the present study presents high characteristics to be used in the development of a healthy snack.