Effects of different foods and cooking methods on the gut microbiota: an in vitro approach

To support personalized diets targeting the gut microbiota, we employed an in vitro digestion-fermentation model and 16S rRNA gene sequencing to analyze the microbiota growing on representative foods of the Mediterranean and Western diets, as well as the influence of cooking methods. Plant- and animal-derived foods had significantly different impacts on the abundances of bacterial taxa. Animal and vegetable fats, fish and dairy products led to increases in many taxa, mainly within the Lachnospiraceae. In particular, fats favored increases in the beneficial bacteria Faecalibacterium, Blautia, and Roseburia. However, butter, as well as gouda cheese and fish, also resulted in the increase of Lachnoclostridium, associated to several diseases. Frying and boiling produced the most distinct effects on the microbiota, with members of the Lachnospiraceae and Ruminococcaceae responding the most to the cooking method employed. Nevertheless, cooking effects were highly individualized and food-dependent, challenging the investigation of their role in personalized diets.

Impact of cooking on the protein quality of Russet potatoes

Despite being low in crude protein, on a fresh weight basis, given their overall contribution to the North American diet, potatoes contribute approximately 2%-4% of the population's protein intake. However, the quality of the protein remains ill-defined. To that end, Russet potatoes were secured and subjected to various cooking conditions (raw [control], boiled, baked, microwaved, and fried [3, 6, and 9 min]) to determine the impact of cooking method on protein quality, as determined by amino acid score (AAS) and indices of in vivo true fecal protein digestibility (TFPD%; rodent bioassay) and in vitro protein digestibility (pH-drop, pH-Stat, and simulated gastrointestinal digestion both static and dynamic). The AAS of raw Russet potatoes was 0.67 ± 0.01, with histidine being the limiting AA. Frying led to a significant reduction in the AAS, however, other cooking methods yielded similar results to the raw control. The TFPD% of raw potato was low (40.5% ± 3.9%) and was significantly enhanced to over 80% with all cooking methods. Similar patterns were observed with all in vitro measures, however, all methods yielded higher values for the raw control samples. Final protein digestibility-corrected AAS (PDCAAS; product of AAS and TFPD%) values ranged from 0.27 (raw) to a high of 0.57 (boiled), with cooked values being comparable to other plant-based protein sources, including grains, and some nuts and pulses. In vitro PDCAAS values followed similar trends. This study defined the protein quality of cooked Russet potatoes and provides data for use in defining the quality of total protein consumed in the North American diet.

Cooking-Induced Oxidation and Structural Changes in Chicken Protein: Their Impact on In Vitro Gastrointestinal Digestion and Intestinal Flora Fermentation Characteristics

Meat digestion and intestinal flora fermentation characteristics are closely related to human dietary health. The present study investigated the effect of different cooking treatments, including boiling, roasting, microwaving, stir-frying, and deep-frying, on the oxidation of chicken protein as well as its structural and digestion characteristics. The results revealed that deep-fried and roasted chicken exhibited a relatively higher degree of protein oxidation, while that of boiled chicken was the lowest (p < 0.05). Both stir-frying and deep-frying led to a greater conversion of the α-helix structure of chicken protein into a β-sheet structure and resulted in lower protein gastrointestinal digestibility (p < 0.05), whereas roasted chicken exhibited moderate digestibility. Further, the impact of residual undigested chicken protein on the intestinal flora fermentation was assessed. During the fermentation process, roasted chicken generated the highest number of new intestinal flora species (49 species), exhibiting the highest Chao 1 index (356.20) and a relatively low Simpson index (0.88). Its relative abundance of Fusobacterium was the highest (33.33%), while the total production of six short-chain fatty acids was the lowest (50.76 mM). Although stir-fried and deep-fried chicken exhibited lower digestibility, their adverse impact on intestinal flora was not greater than that of roasted chicken. Therefore, roasting is the least recommended method for the daily cooking of chicken. The present work provides practical advice for choosing cooking methods for chicken in daily life, which is useful for human dietary health.

Physicochemical Properties and Volatile Organic Compounds of Dairy Beef Round Subjected to Various Cooking Methods

To evaluate the effect of different cooking methods on the physicochemical quality and volatile organic compounds (VOC) of dairy beef round, twelve beef round pieces were divided into four groups: raw, boiling, microwave, and sous-vide. The sous-vide group had a higher pH than the boiling or microwave groups. The boiling group exhibited the highest shear force and CIE L*, followed by the microwave and sous-vide groups (p<0.05). The sous-vide group received higher taste and tenderness scores from panelists (p<0.05) and showed significantly higher levels of aspartic and glutamic acids than the other groups. The sous-vide and microwave groups had the highest oleic acid and polyunsaturated fatty acid levels, respectively. The sous-vide group had significantly higher hypoxanthine and inosine levels than the other groups. However, the microwave group had higher inosine monophosphate levels than the other groups. The sous-vide group had a higher alcohol content, including 1-octen-3-ol, than the other groups. Octanal and nonanal were the most abundant aldehydes in all groups. (R)-(-)-14-methyl-8-hexadecyn-1-ol, p-cresol, and 1-tridecyne were used to distinguish the VOC for each group in the multivariate analysis. Sous-vide could be effective in increasing meat tenderness as well as taste-related free amino acid (aspartic acid and glutamic acid) and fatty acid (oleic acid) levels. Furthermore, specific VOC, including 1-octen-3-ol, 2-ethylhexanal ethylene glycol acetal, and 2-octen-1-ol, (E)-, could be potential markers for distinguishing sous-vide from other cooking methods. Further studies are required to understand the mechanisms underlying the predominant association of these VOC with the sous-vide cooking method.

Effect of Purple Sweet Potato Using Different Cooking Methods on Cytoprotection against Ethanol-Induced Oxidative Damage through Nrf2 Activation in HepG2 Cells

The aim of this study was to investigate the effects of different cooking methods on the hepatoprotective effects of purple sweet potatoes against alcohol-induced damage in HepG2 cells. Purple sweet potatoes (Ipomeoea batatas L. Danjami) were subjected to different cooking methods, including steaming, roasting, and microwaving. Steaming resulted in a higher cytoprotective effect against alcohol damage than the other cooking methods. Additionally, the highest inhibition of glutathione depletion and production of reactive oxygen species against alcohol-induced stress were observed in raw and/or steamed purple sweet potatoes. Compared to roasted and/or microwaved samples, steamed samples significantly increased the expression of NADPH quinone oxidoreductase 1, heme oxygenase 1, and gamma glutamate-cysteine ligase in alcohol-stimulated HepG2 cells via the activation of nuclear factor erythroid 2-related factor 2. Moreover, ten anthocyanins were detected in the raw samples, whereas five, two, and two anthocyanins were found in the steamed, roasted, and microwaved samples, respectively. Taken together, steaming purple sweet potatoes could be an effective cooking method to protect hepatocytes against alcohol consumption. These results provide useful information for improving the bioactive properties of purple sweet potatoes using different cooking methods.

Effects of Different Cooking Methods on Phenol Content and Antioxidant Activity in Sprouted Peanut

Peanut sprout is a high-quality healthy food, which not only has beneficial effects, but also a higher phenol content than peanut seed. In this study, peanut sprout was treated with five cooking methods, namely boiling, steaming, microwave heating, roasting, and deep-frying, and the phenol content, monomeric phenol composition, and antioxidant activity were determined. The results showed that, compared with unripened peanut sprout, the total phenol content (TPC) and total flavonoid content (TFC) decreased significantly after the five ripening processes, and the highest retention of phenols and flavonoids was associated with microwave heating (82.05% for TPC; 85.35% for TFC). Compared with unripened peanut sprout, the monomeric phenol composition in germinated peanut was variable after heat processing. After microwave heating, except for a significant increase in the cinnamic acid content, no changes in the contents of resveratrol, ferulic acid, sinapic acid, and epicatechin were observed. Furthermore, there was a significant positive correlation of TPC and TFC with 2,2-diphenyl-1-picrylhydrazyl scavenging capacity, 2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) scavenging capacity, and ferric ion reducing antioxidant power in germinated peanut, but not with hydroxyl free radical scavenging capacity, in which the main monomer phenolic compounds were resveratrol, catechin, and quercetin. The research results indicate that microwave heating can effectively retain the phenolic substances and antioxidant activity in germinated peanuts, making it a more suitable ripening and processing method for germinated peanuts.

Vitamin D Content in Commonly Consumed Mushrooms in Thailand and Its True Retention after Household Cooking

This study investigated the vitamin D level of nine species of cultivated mushrooms and three species of wild mushrooms commonly consumed in Thailand and the effect of cooking on their vitamin D content. Cultivated mushrooms were obtained from three wholesale markets, while wild mushrooms were collected from three trails in a conservation area. Mushrooms from each source were separated into four groups: raw, boiled, stir-fried, and grilled. Different forms of vitamin D were analyzed using liquid chromatography with tandem mass spectrometry (LC-MS/MS). The analyzed method demonstrated good linearity, accuracy, and precision, as well as being low in the limit of detection and limit of quantitation. Results showed that vitamin D2 and ergosterol (provitamin D2) were the major forms of vitamin D found in the mushrooms. Both raw cultivated and wild mushrooms had wide ranging ergosterol contents (7713-17,273 μg/100 g edible portion, EP). Lung oyster mushroom and termite mushroom contained high levels of vitamin D2 (15.88 ± 7.31 and 7.15 ± 0.67 μg/100 g EP, respectively), while other mushroom species had negligible amounts (0.06 to 2.31 μg per 100 g EP). True retention (TR) levels of vitamin D2 after boiling, stir-frying, and grilling were not significantly different (p > 0.05) (with estimated marginal means ± standard error 64.0 ± 2.3%, 58.8 ± 2.3%, and 64.7 ± 3.6% TR, respectively). Consuming cooked lung oyster mushrooms, in particular, along with regular exposure to sunlight should be promoted to reduce the incidence of vitamin D deficiency.

Effect of Cooking Method and Doneness Degree on Volatile Compounds and Taste Substance of Pingliang Red Beef

This study used gas chromatography-ion mobility spectrometry (GC-IMS) and high-performance liquid chromatography (HPLC) methods to examine the impact of cooking methods and doneness on volatile aroma compounds and non-volatile substances (fatty acids, nucleotides, and amino acids) in Pingliang red beef. The flavor substances' topographic fingerprints were established, and 45 compounds were traced to 71 distinct signal peaks. Pingliang red beef's fruity flavor was enhanced thanks to the increased concentration of hexanal, styrene, and 2-butanone that resulted from instant boiling. The levels of 3-methylbutanal, which contributes to the characteristic caramel-chocolate-cheese aroma, peaked at 90 min of boiling and 40 min of roasting. The FFA content was reduced by 28.34% and 27.42%, respectively, after the beef was roasted for 40 min and instantly boiled for 10 s (p > 0.05). The most distinctive feature after 30 min of boiling was the umami, as the highest levels of glutamate (Glu) (p < 0.05) and the highest equivalent umami concentration (EUC) values were obtained through this cooking method. Additionally, adenosine-5'-monophosphate (AMP) and inosine-5'-monophosphate (IMP) decreased with increasing doneness compared to higher doneness, indicating that lower doneness was favorable in enhancing the umami of the beef. In summary, different cooking methods and doneness levels can affect the flavor and taste of Pingliang red beef, but it is not suitable for high-doneness cooking.

Effect of Different Cooking Methods on Nutrients, Antioxidant Activities and Flavors of Three Varieties of Lentinus edodes

This work evaluated the effect of different cooking methods (boiling, steaming, microwaving, frying and pressure cooking) on the nutrients, antioxidant activities, volatile and nonvolatile taste-active components of three varieties of Lentinus edodes (808, 0912 and LM) from Guizhou Province. The results showed that LM had the most polysaccharides, 0912 had the most minerals, but LM, 808 and 0912 had low amounts of polyphenols, dietary fiber and proteins, respectively. The dietary fiber and protein were decreased by 4.1~38.7% and 4.1~44.0% during cooking, while microwaving improved the nutritional value of the Lentinus edodes by increasing the polysaccharide (88~103 mg/g to 93~105 mg/g) and polyphenol content (6.4~8.1 mg/g to 7.5~11.2 mg/g), thereby strengthening the antioxidant activity. The nucleotides were all destroyed after cooking, especially frying or boiling. The glutamate content was the highest in LM and 808, and the methionine content appeared to be the highest in 0912. Pressure cooking and frying increased the proportions of sweet and umami amino acids and decreased the proportion of bitter amino acids, creating more aroma-active compounds. In summary, microwaving increased the content of bioactive compounds and antioxidant activities, and it preserved nonvolatile taste-active components, while pressure cooking and frying were the best methods for increasing the flavor compounds.

Effects of Different Cooking Methods on the Vitamin D Content of Commonly Consumed Fish in Thailand

This study determined vitamin D content in commonly consumed fish in Thailand and the effects of different cooking methods on vitamin D retention. Five species of freshwater fish and four species of marine fish were purchased from three representative markets. All of the fish were individually prepared according to common household practices. Vitamin D2 and D3 were determined using the HPLC standard method (AOAC method 995.05). The results indicated that vitamin D3 was the only detectable form of vitamin D in the fish. Vitamin D content of raw freshwater fish ranged from 2.42 to 48.5 µg per 100 g edible portion (EP), which was higher than that of raw marine fish (2.94 to 4.69 µg per 100 g EP). Common silver barb, Red Nile tilapia, and Nile tilapia (freshwater fish living in the limnetic zone) contained high levels of vitamin D (48.5 ± 26.5, 31.0 ± 7.7, and 19.8 ± 3.5 µg per 100 g EP, respectively). Boiled fish (except for Common silver barb), fried fish (except for Striped snakehead, Walking catfish, and Common silver barb), and grilled fish (except for Common silver barb, Giant sea perch, and Short-bodied mackerel) retained high levels of vitamin D, which were not significantly different (p > 0.05) from raw fish. Common silver barb, Red Nile tilapia, and Nile tilapia—cooked by boiling, frying, and grilling—are recommended for consumption as excellent sources of vitamin D.

Effects of Dietary Pork Fat Cooked Using Different Methods on Glucose and Lipid Metabolism, Liver Inflammation and Gut Microbiota in Rats

Cooking may affect the nutritional value of pork fat, and, nowadays, people have been paying an increasing amount of attention to the method of cooking. In this study, the effects of dietary pork fat cooked using different methods on body metabolism and intestinal microbes were studied in rats. Fat was extracted from pork belly meat cooked using three methods: braising (braising cooking method, BCM), stewing (SCM) and deep fat frying (DCM). The three types of pork fat were added to animal feed, and the effects of each on body weight, glucose and lipid metabolism, liver inflammation and intestinal microbes in rats were compared with the effects of soybean oil-treated feed (SO) and a blank control (BC). Rats in all three groups fed with cooked pork fat exhibited significant increases in body weight compared with the controls across the experimental feeding period. Furthermore, all three types of pork fat led to significant changes in the serum concentrations of triglycerides (TG) and total cholesterol (TC) relative to the controls, with the greatest increases in TG and TC in the BCM and DCM groups, respectively. All three types of pork fat led to significant decreases in serum high-density lipoprotein cholesterol concentrations relative to the controls, with the lowest concentration in the SCM group. All three types of pork fat also led to significant increases in low-density lipoprotein cholesterol concentrations relative to the controls, with the smallest increase in the DCM group. Rats in the SCM group had the highest level of liver fat deposition, followed by those in the BCM, DCM, SO and BC groups. Compared with the controls, the three groups fed with different types of cooked pork fat had significantly lower hepatic expression of nuclear transcription factor kappa B (NF-κB). The expression levels of NF-κB in the DCM and SO groups were significantly lower than those in the other groups. The abundance of Proteobacteria species in the intestines of rats was significantly lower in the BC group than in the other groups fed with cooked pork fat, and the abundance of Bacteroidetes species was significantly lower in the BCM, SCM and DCM groups than in the BC and SO groups. From the changes in the abundance of Firmicutes and Bacteroides, pork fat in the three cooking methods has a certain potential to promote the production of body obesity.

Effect of geographical location, insect type and cooking method on the nutritional composition of insects consumed in South Africa

Edible insects may be a sustainable source of protein and some other nutrients, especially for low-economic-status communities. The current study determined the influence of insect type, geographic location, and cooking method on the nutritional composition of insects. The investigation would contribute to the maximal derivation of the nutritional benefits of insects. Dried samples of four insect types, G. belina (mopani worm), Gynanisa caterpillar, termite soldiers/workers, and termite alates, were procured from different street vendors across Vhembe district in Limpopo Province, South Africa. G. belina samples were cooked by frying, boiling with and without salt addition. Generally, nutrient content varied significantly with insect type and geographic location (p<0.05). Protein content varied from 40 g/100 g in termite alates to 69.75 g/100 g in termite soldiers/workers. Termite soldiers/workers had the highest iron content (range: 545-629.5 mg/kg), whilst Gynanisa caterpillar had the highest zinc content (range: 122.14-150.33 mg/kg). Similarly, Gynanisa caterpillar had the highest levels of lysine (range: 0.80-4.53 g/100g), threonine (range: 0.79-2.64 g/100g) and isoleucine (range: 0.63-2.33). On the other hand termite soldiers/workers had the highest levels of valine (range: 2.20-3.47 g/100g), leucine (range: 2.49-3.87 g/100g) and phenylalanine (range: 1.38-3.55 g/100g). Cooking method significantly affected nutrient retention. Boiling with salt added resulted in the highest retention of protein and total mineral content (ash), and, therefore, seems a suitable method for cooking insects. The findings indicate that, if optimally selected and cooked, edible insects can contribute significantly to the alleviation of protein, zinc, and iron deficiencies in target communities.

Influence of Cooking Method on the Nutritional Quality of Organic and Conventional Brazilian Vegetables: A Study on Sodium, Potassium, and Carotenoids

Vegetable consumption is associated with increased health benefits, and vegetables are consumed both in cooked form and raw form in salads. All cooking techniques cause changes in a vegetable’s the nutrient content. Consumers are increasingly health-conscious and have less time to prepare meals, and they do not know which cooking times and cooking methods are best suited to preserve the nutrients. This study aimed to determine the best method of cooking vegetables to maintain minerals (potassium and sodium) and carotenoids. The studied vegetables were broccoli (Brassica oleracea, var. Italica), carrots (Daucus carota), and zucchini (Cucurbita moschata). The cooking methods were: boiling, steaming, combined oven, microwave steaming, and microwave cooking. Samples of organic and conventionally grown vegetables were prepared in triplicate. Samples were analyzed to determine the availability of target minerals and carotenoids in the raw food and in each recommended cooking situation according to technical standards. Only the carrot showed a higher concentration in organic cultivation for carotenoids in raw vegetables, with both zucchini and broccoli having higher concentrations when grown by conventional cultivation. The zucchini from organic cultivation presented a reduction of potassium and sodium, almost consistently, in all cooking techniques. Regarding the conventionally cultivated zucchini, potassium remained stable in boiling. Broccoli from organic and conventional cultivation showed similar potassium levels for boiling and traditional steam cooking. Organic carrots showed easier sodium extraction compared with conventional cultivation. Heat treatment, in general, improves the accessibility of carotenoids.

Effects of different cooking methods on volatile flavor compounds of chicken breast

Chicken is one of the highest selling meats worldwide. Different cooking methods produce various flavor compounds in cooked chicken, which affect consumers' food choices. In this study, the volatile flavor components of Gushi chicken breast after stewing and air frying were detected using gas chromatography-ion mobility chromatography (GC-IMS) and principal component analysis (PCA), and the relative odor activity value (ROAV) was determined using PCA. A total of 43 volatile substances were identified. 3-(methylthio)propionaldehyde-M and benzene acetaldehyde can be used as characteristic flavor markers in the air-fried chicken breast.ethyl acetate, (E)-2-octenal-D, and 2-ethyl-1-hexanol-D can be used as characteristic flavor markers in the stewed chicken breast. Because these five substances have the most obvious contrast in the fingerprint. The following part describes the specific substances that have mainly contributed to the flavor system in the volatile system obtained by different cooking methods. Finally, the main flavor compounds of the stewed chicken breast were 3-methylbutanal-D, octanal-D, (E)-2-nonenal, and other 11 types of compounds (ROAV ≥1). Nine types of compounds (ROAV ≥1), including 3-methylbutanal-D, (E)-2-nonenal-M octanal-M, and hexanal-M, were the main compounds to characterize the air-fried chicken breast. PRACTICAL APPLICATIONS: GC-IMS technology combined with the principal component analysis of ROAV can be used to rapidly identify the main flavor substances and the flavor substances having an important role in modifying the overall taste of the sample. It plays a considerably important role in the aroma recombination of substances and can play a role in food processing.

Insights into Digestibility and Peptide Profiling of Beef Muscle Proteins with Different Cooking Methods

This study aimed to investigate theeffects of sous vide (SV), boiling (BO), and roasting (RO) on beef protein digestibility and peptide profiling in simulated gastrointestinal digestion. The results indicated that beef samples treated with SV had higher (p < 0.05) gastrointestinal digestibility (34.97%) than those treated with BO (27.59%) and RO (24.36%). Furthermore, SV (2450) resulted in more types of peptides released during gastrointestinal digestion than BO (2077) and RO (1896) and a higher proportion of 400-1200 Da peptides. The significant increase of carbonyl content, the decrease of sulfhydryl content, and the formation of covalent bonds coupled with the transformation of protein secondary structure from α-helix to β-sheet suggested that excessive protein oxidation and aggregation occurred in BO and RO samples. These changes in BO and RO samples might explain the decreased protein digestibility and peptide release in gastrointestinal digestion. Thus, SV is a promising cooking method to improve beef protein digestibility.

Changes in the volatile components of squid (illex argentinus) for different cooking methods via headspace-gas chromatography-ion mobility spectrometry

Squid products are becoming more and more popular with consumers because of their high yields and nutrition, including novel textures with desirable sensory properties. However, it has not been determined whether the cooking method has effects on the flavor of the squid. In this study, the aroma and volatile substances of squid samples from different cooking methods (boiled, steamed, sous vide) were determined and analyzed by headspace-gas chromatography-ion mobility spectrometry and differentiated by using, as well, an electronic nose and sensory evaluation. A total of 43 characteristic flavor compounds were identified. Based on the signal intensity of the identified violate compounds, we established a fingerprint of heat-treated squid from different cooking methods. Due to the long-term low-temperature heating conditions under vacuum, the flavor of sous vide squid is different from steamed and boiled squid, and it has unique special flavor compounds. Different cooking methods can affect the aroma of squid, providing support for the industrial production of squid.

Effect of washing, soaking, and cooking methods on perfluorinated compounds in mackerel (Scomber japonicus)

Perfluorinated compounds (PFCs) are environmental pollutants, and dietary intake is a major route of human exposure to them. We aimed to see the effects of washing, soaking, and cooking (grilling, braising, frying, and steaming) on the change of PFCs in mackerel fillets and PFCs before and after each treatment were analyzed using LC-MS/MS. Washing resulted in a decrease in the PFC content of mackerel (average 74%) comparing to control. Among the 19 PFCs detected, perfluorobutanoic acid and perfluorotridecanoic acid (PFTrDA) were found to be abundant after washing. Soaking mackerel in sake reduced its PFC content by 51%, whereas soaking in rice-washed solution reduced by 80% comparing to control. All the four cooking methods were effective in reducing the PFC content of mackerel. The degree by which the PFC content decreased varied with the cooking method: grilling (91%), steaming (75%), frying (58%), and braising (47%) comparing to uncooked sample. In addition, when mackerel was braised with potato, PFCs decreased more in fillet than the ones without potato. PFCs in potato increased after cooking with mackerel. The excessive consumption through the mackerel was 0.1997 ng/kg bw/day and 0.7987 ng/kg bw/day, respectively. These exposure levels were well below the tolerable daily intake values of both compounds (PFOS, 150 ng/kg bw/day; PFOA, 1,500 ng/kg bw/day). The results of this study indicated that employing appropriate pretreatment and cooking methods could be an effective way to reduce the dietary exposure to PFCs in mackerel.

Fish Cooking Methods and Impaired Glucose Metabolism Among Japanese Workers: The Furukawa Nutrition and Health Study

The aim of this study was to examine the cross-sectional association between fish and shellfish intake and impaired glucose metabolism with consideration for cooking methods in a Japanese working population. Participants were 1774 workers aged 18-69 years. Dietary intake was assessed using a validated self-administered diet history questionnaire. Participants were asked about their most frequently used cooking method for fish, and the method was classified as either "raw and stewing" or "broiling, deep-frying, and stir-frying". Impaired glucose metabolism was defined by a history of diabetes, current use of anti-diabetic drugs, fasting blood glucose ≥110 mg/dl, or HbA1c ≥6.0%. Logistic regression analysis was used to estimate the odds ratios of impaired glucose metabolism for fish intake by cooking method. Fish intake was not associated with impaired glucose metabolism in either group. When the outcome was defined as diabetes, the odds of diabetes increased with fish intake among participants who most frequently used broiling, deep-frying, or stir-frying methods, albeit they were not statistically significant; the multivariable-adjusted odds ratio for the highest versus the lowest tertiles of fish intake was 1.95 (95%CI, 0.71-5.41). Cooking methods for fish may not modify the association between fish intake and impaired glucose metabolism among Japanese populations.

Influence of Cooking Conditions on Nutritional Properties and Sensory Characteristics Interpreted by E-Senses: Case-Study on Selected Vegetables

This study investigates the effects of three cooking methods (boiling, steaming and microwaving) on the nutritional and physical properties of cauliflowers, carrots and sweet potatoes; e-senses were applied to interpret the sensory characteristics according to physico-chemical aspects. The nutritional quality was evaluated by determining the concentrations of key components and the antioxidant activity; e-sense data, combined with texture parameters, were processed by a principal component analysis. The cooking method and time significantly influenced the quality of the three products. Boiling, which detrimentally affected ascorbic acid, total phenolic concentration and antioxidant activity, enhanced carotene accessibility. Steaming produced losses in ascorbic acid, increasing total phenolics and carotenoids. Microwaving resulted in minor changes in ascorbic acid concentrations, preserved carotenoids and increased total phenolics. The nutritional quality was better preserved or enhanced using shorter cooking times. The elaboration of the data collected by the e-senses showed a clear evolution according to the cooking method and time. The results helped to determine the cooking method that best preserves the nutritional properties of the vegetables, highlighting the applicability of rapid instrumental methods to interpret the evolution of sensory characteristics.

Determining Which Cooking Method Provides the Best Sensory Differentiation of Potatoes

There are many ways to prepare potatoes that each provide a unique set of sensory properties. However, when conducting a descriptive sensory study, it is important to utilize a cooking method that will highlight, and not distract from, the sensory differences among potato samples due to factors such as variety or growing conditions. This study aimed to determine which of five cooking methods results in the best differentiation among potato varieties to recommend a single method for use in future descriptive sensory studies. Five different potato varieties were each prepared using boiling, mashing, baking, frying, and air frying methods. The samples were provided to six highly trained descriptive panelists and evaluated by consensus using a modified high identity traits (HITs) method. Panelists evaluated the aroma, flavor, and texture to develop a list of up to five total HITs per sample. Additionally, panelists scored each sample for degree of difference (DOD) from the control. Based on the HITs profiles and DOD scores, mashing, baking, and air frying methods were all effective in differentiating the samples. Frying and boiling methods introduced too much variation and are not recommended for sample differentiation. Ultimately, the method chosen for future research would depend on the study objectives.

Effect of different cooking methods on sensory quality assessment and in vitro digestibility of sturgeon steak

Sous vide can keep the nutritional properties and improve taste of food compared with other conventional methods. In addition, this method may reduce the risk of recontamination after cooking and during storage. The purpose of this paper was to study the effects of four cooking methods (steaming, microwaving, baking, and frying) on the sensory and digestibility on sturgeon steak pretreated by sous vide during the cold storage (0-25 days). The results showed that the digestibility of steaming and microwaving groups (range from 80.34% to 90.12%) significantly higher than that of the other treatment groups (p < .05); however, the overall acceptability of the two groups was lower. What more, the frying group has the highest acceptability and the lowest digestibility (range from 65.12% to 70.89%). The springiness (4.12-6.56 mm) and chewiness (1.75-3.12 mm) of the frying group were significantly higher than those of the other treatment groups, which was consistent with the results of scanning electron microscopy (SEM) that frying treatment group has a denser structure and smaller pores. With the prolonged refrigeration time, especially between 15 and 25 days, the volatile flavor components (nitrogen oxide, methane, and alcohol) and stagnant water (T21) were significantly decreased. Principal component analysis showed that the moisture content was the main factor affecting the overall acceptability and best consumption time of the sturgeon was within 15 days. Simulating the effects of home cooking conditions and refrigeration storage time on the quality of sturgeon steak provided a reference for consumers using similar products.

Assessment of the dynamics of sensory perception of Wagyu beef strip loin prepared with different cooking methods and fattening periods using the temporal dominance of sensations

In this study, we assessed the relative sensory perception of Wagyu beef using temporal dominance of sensations (TDS), which is a dynamic sensory method that captures the "dominance of sensation" throughout food consumption. In addition, we checked the integrity of the TDS by comparing the TDS results with a physicochemical analysis. Strip loins were obtained from 24- and 28-month-old Japanese Black cattle ("Wagyu") and were cooked by grilling (yakiniku) or boiling (shabu-shabu). Temporal dominance of sensations was then used to evaluate the four types of samples. "Tender and/or soft," "juicy," "dry," "fat melting," "fat taste," "umami," "sweet taste," and "butter odor" were dominant in at least one of the sample types, with the yakiniku cooking method highlighting texture- and fat-related sensory characteristics, and the shabu-shabu cooking method highlighting flavor-related sensory characteristics. In addition, beef obtained from the 24-month-old Wagyu was significantly more "dry" than that of the 28-month-old cattle, reflecting their different cooking loss. Temporal dominance of sensations successfully demonstrated the dominant sensory perceptions of Wagyu beef prepared with different cooking methods and fattening periods.

Detection of p-Nitroaniline Released from Degradation of 4,4'-Dinitrocarbanilide in Chicken Breast during Thermal Processing

The diphenylurea 4,4'-dinitrocarbanilide (DNC) is the residue of concern left in edible tissues of broilers fed diets containing the anticoccidial nicarbazin. When chicken meat is submitted to thermal processing, p-nitroaniline (p-NA) is expected from DNC degradation. This work aimed at evaluating whether thermal processing of DNC-containing chicken meat induces p-NA appearance. First, a hydrolysis assay was performed in aqueous solutions at 100 °C in different pH, confirming that DNC cleavage yields p-NA. Then a novel LC-MS/MS method was used to detect traces of this aromatic amine in DNC-containing chicken breast fillets subjected to cooking methods. Our evidence showed p-NA occurrence in such chicken meat samples, which corroborated results from hydrolysis assay. The p-NA appearance in fillets was rather discrete during boiling treatment, but its concentration became pronounced over time for grilling, frying, and roasting, achieving respectively 326.3, 640.0, and 456.9 μg/kg. As far as we are concerned, no other research identified degradation products from DNC residue in heat-processed chicken fillets. Therefore, this study leads to additional approaches to assess impacts on food safety.

Validity of a Self-administered Food Frequency Questionnaire for the Estimation of Acrylamide Intake in the Japanese Population: The JPHC FFQ Validation Study

BACKGROUND

Acrylamide, a probable carcinogen to humans, forms during high temperature cooking. Dietary exposure to acrylamide among the Japanese population is unknown. We aimed to establish and validate a method to assess acrylamide exposure among the Japanese population using a food frequency questionnaire (FFQ) from the Japan Public Health Center-based prospective study.

METHODS

Validation studies for the FFQ were conducted in 1994 (Cohort I, n = 215) and 1996 (Cohort II, n = 350). The 28-day dietary records (DRs) were collected over 1 year. The FFQ was distributed before and after DR collection. Data for acrylamide exposure were based on reported measurements in Japan, and calculations considered the cooking process for specific vegetables in a home setting. Spearman's rank correlation and weighted kappa coefficients were calculated from energy-adjusted data.

RESULTS

Mean acrylamide intake levels estimated from DRs for Cohorts I and II were 6.78 (standard deviation [SD], 3.89) µg/day and 7.25 (SD, 3.33) µg/day, and corresponding levels estimated from the FFQ were 7.03 (SD, 4.30) µg/day and 7.14 (SD, 3.38) µg/day, respectively. Deattenuated correlation coefficients for men and women were 0.54 and 0.48 in Cohort I and 0.40 and 0.37 in Cohort II, respectively. Weighted kappa coefficients were over 0.80 in all cases. The main contributing food groups from DRs were beverages, confectioneries, vegetables, potatoes and starches, and cereals.

CONCLUSIONS

High kappa values validate the use of FFQ in epidemiological studies. The marked contribution of cooked vegetables indicates the importance of considering household cooking methods in assessing acrylamide intake levels in the Japanese population.

Degradation of 4,4'-Dinitrocarbanilide in Chicken Breast by Thermal Processing

Nicarbazin is one of the major anticoccidials used in broiler feeds. The compound 4,4'-dinitrocarbanilide (DNC) is the marker residue of concern left from nicarbazin in chicken meat. The effect of thermal processing on DNC content accumulated in chicken breast was assessed, and samples were analyzed by liquid chromatography-tandem mass spectrometry. Five conventional cooking methods were evaluated: boiling, grilling, microwaving, frying, and roasting. To ensure DNC in meat, broilers were fed nicarbazin without withdrawal period. All heating methods surpassed the 70 °C end point core temperature in chicken breast. Maximum DNC degradation was reached at 10 min for boiling, at 30 min for grilling, and at 2 min for microwaving, and no further reduction was observed for longer thermal processing time. Boiling was more efficient in reducing DNC (69%). Grilling, microwaving, and frying achieved on average 55% of degradation. The outcomes reported herein may be considered in decision-making regarding further review of maximum residue limits.

Preferring fried dishes increases risk of benign breast disease, but not breast cancer

BACKGROUND

Unhealthy diet and cooking method used may influence the risk of breast cancer (BC), but there is only limited evidence with regard to benign breast disease (BBD). The aim of this study was to assess a relationship between cooking technique, especially fried to boiled meals ratio in the diet, and the risk of BC and BBD in a group of Polish women.

MATERIAL AND METHODS

A case-control study involving 34 BC cases, 81 BBD cases and 122 healthy controls was conducted between July 2007 and November 2011. All the women were asked about their nutritional habits, especially the way of preparing meat and fish dishes. Then the ratio of fried to boiled meals was calculated.

RESULTS

High fried to boiled ratio was associated with increasing risk of BBD, but not BC. Women consuming fried dishes more often than boiled dishes had elevated risk of BBD: OR = 3.04 and OR = 3.65 for the second and the third tertile, respectively. Adjustment for the other confounders only slightly altered this relationship.

CONCLUSION

Women who preferred frying as a cooking technique had increased risk of benign breast disease, but not breast cancer. There is a need of more precise investigation to confirm this association.

A Comparison of the Essential Amino Acid Content and the Retention Rate by Chicken Part according to Different Cooking Methods

This study set out to identify the changes in the nutrient contents during the chicken cooking process as basic data for the establishment of a national health nutrition policy. Samples were produced using 3 chicken parts (wing, breast, and leg) and 7 cooking methods (boiling, pancooking, pan-frying, deep-frying, steaming, roasting, and microwaving), and the essential amino acid contents, principal components, and retention rates were analyzed. Weight loss was observed in all chicken parts with all cooking methods. The protein and essential amino acid contents of the chicken samples differed significantly according to the part and the cooking method (p<0.01). The protein and essential amino acid contents (g/100 g) of raw and cooked chicken parts showed ranges of 16.81-32.36 and 0.44-2.45, respectively. The principal component analysis (PCA) clearly demonstrated that the cooking methods and chicken parts produced similar trends for the essential amino acid contents. The retention rates of the chicken parts varied with the cooking methods, yielding a minimum value of 83% for isoleucine in a roasted wing, 91% for protein in a steamed breast, and 77% for isoleucine and lysine in a roasted leg. Therefore, the protein and amino acid contents of the roasted breast were higher than those of the other cooked chicken parts.

Effects of cooking methods on the β-carotene levels of selected plant food materials

In the present study, the β-carotene contents of 14 plant food materials prepared by boiling, steaming, or baking or when they are raw were analyzed and compared. After boiling three pulse species, namely, peas, kidney beans, and dried mung beans, β-carotene contents of peas and kidney beans increased significantly, whereas that of mung beans (dried material) decreased. True retention factors of β-carotene contents in the cooked kidney beans, peas, and mung beans after boiling were 174.2, 128.3, and 91.8%, respectively. After steaming, the β-carotene content of regular millets significantly decreased but that of taros increased, in which the true retention factors were observed with β-carotene contents of 72.4% in the steamed regular millets and 160.9% in the steamed taros. Moreover, β-carotene contents in yellow-fleshed sweet potato (raw: 896.2 μg/100 g) decreased by baking (786.4 μg/100 g) and steaming (steaming: 553.1 μg/100 g). These results suggest that β-carotene contents in the selected plant food materials markedly depend on the cooking method and plant food materials classification.

Sensory quality of broiler breast meat influenced by low atmospheric pressure stunning, deboning time and cooking methods

Stunning method (low atmospheric pressure stunning, LAPS and electrical stunning, ES), deboning time (0.75 h and 4 h), and cooking method (baking, frying, and sous vide) were evaluated for their impact on the descriptive sensory characteristics and consumer acceptability of breast meat (n=576, 144 birds per stunning × deboning time combination). Sensory evaluation was conducted by trained descriptive (n=8) and consumer (n=185) panels. On average, no differences (P>0.05) existed in the sensory acceptability of fried and sous vide cooked broiler breast treatment combinations. However, for oven-baking, the LAPS treatment that was deboned at 4 h was more acceptable (P<0.05) than other treatments and the ES and LAPS 4 h samples had greater (P<0.05) acceptability for texture than their ES and LAPS 0.75 h counterparts. Since consumers were highly variable in their liking of chicken breast treatments, consumers were grouped into clusters for each cooking method based on liking and preference. Cluster analysis data revealed that the largest groups of consumers liked (score≥6.0) all chicken breast treatments, but a larger proportion of consumers liked the 4 h LAPS and ES treatments when compared to the 0.75 h LAPS and ES treatments for all cooking methods. In addition, the consumers who indicated that baked chicken breast was highly acceptable preferred (P<0.05) 4 h LAPS over the 4 h ES samples. Based on sensory results, chicken breast meat from all stunning and deboning method combinations was highly acceptable to the majority of consumers, but the LAPS 4 h treatment had enhanced sensory characteristics when baked.

Effect of cooking methods on cholesterol, mineral composition and formation of total heterocyclic aromatic amines in Muscovy drake meat

BACKGROUND

Cholesterol, minerals and heterocyclic aromatic amines (HAAs) are of great importance in determining meat quality to humans and therefore of concern to meat consumers because of health reasons. The objective of this study was to evaluate the effects of various cooking methods (grilling, deep frying, pan frying and roasting) on the formation of total HAAs, cholesterol and mineral retention in Muscovy drake breast meat. Total HAAs and cholesterol were determined by high-performance liquid chromatography, while minerals were measured by atomic absorption spectroscopy.

RESULTS

Muscovy drake breast meat cooked by deep frying had the highest content of total HAAs (31.83 ng g(-1)), followed by roasted (30.12 ng g(-1)), pan-fried (29.23 ng g(-1)) and grilled (27.34 ng g(-1)) fillets. The cholesterol content was highest in deep-fried fillets (59.09 mg g(-1)), followed by roasted fillets (58.61 mg g(-1)), while grilling resulted in the lowest cholesterol content (57.00 mg g(-1)). The mineral content was highest in deep-fried samples and lowest in roasted fillets. Magnesium retention was affected by the cooking method and was higher in deep-fried samples (110.57%) than in grilled (97.97%), pan-fried (88.99%) and roasted (78.46%) fillets. Generally, the total HAA, cholesterol and mineral content in cooked Muscovy drake breast meat varied with the cooking method.

CONCLUSION

Moderate consumption of deep-fried Muscovy drake meat should be encouraged, as deep frying increased its cholesterol, total HAA and mineral content compared with the other cooking methods investigated.

Effects of cooking methods and starch structures on starch hydrolysis rates of rice

This study aimed to understand effects of different cooking methods, including steamed, pilaf, and traditional stir-fried, on starch hydrolysis rates of rice. Rice grains of 3 varieties, japonica, indica, and waxy, were used for the study. Rice starch was isolated from the grain and characterized. Amylose contents of starches from japonica, indica, and waxy rice were 13.5%, 18.0%, and 0.9%, respectively. The onset gelatinization temperature of indica starch (71.6 °C) was higher than that of the japonica and waxy starch (56.0 and 56.8 °C, respectively). The difference was attributed to longer amylopectin branch chains of the indica starch. Starch hydrolysis rates and resistant starch (RS) contents of the rice varieties differed after they were cooked using different methods. Stir-fried rice displayed the least starch hydrolysis rate followed by pilaf rice and steamed rice for each rice variety. RS contents of freshly steamed japonica, indica, and waxy rice were 0.7%, 6.6%, and 1.3%, respectively; those of rice pilaf were 12.1%, 13.2%, and 3.4%, respectively; and the stir-fried rice displayed the largest RS contents of 15.8%, 16.6%, and 12.1%, respectively. Mechanisms of the large RS contents of the stir-fried rice were studied. With the least starch hydrolysis rate and the largest RS content, stir-fried rice would be a desirable way of preparing rice for food to reduce postprandial blood glucose and insulin responses and to improve colon health of humans.

A prospective study of stomach cancer among a rural Japanese population: a 6-year survey

Stomach cancer mortality was prospectively studied among 9753 Japanese men and women who first responded to a mailed questionnaire in 1985 and were then followed through May 31, 1991. During this follow-up period, 57 stomach cancer deaths were identified. Current smokers had an increased risk of deaths from stomach cancer compared with never smokers (relative risk (RR) = 2.29, 95% confidence interval (CI): 1.15-4.56), but there was no dose-response to amount of cigarettes smoked. Daily alcohol drinkers who consumed 50 ml or more of alcohol per day also had a greater risk than nondrinkers (RR = 3.05, 95% CI: 1.35-6.91). There was no association between stomach cancer mortality and individual food consumption except a positive association with fruit intake. However, frequent use (greater than or equal to 3-4/week) of broiling of meats and traditional style Japanese salad preparation in their cooking procedures were positively associated with stomach cancer mortality. The RR values compared with infrequent use (less than or equal to 1-2/month) were 2.27 (95% CI: 1.06-4.85) and 3.10 (95% CI: 1.40-6.85), respectively. A positive family history of cancer, especially stomach cancer, significantly increased the risk of stomach cancer deaths (RR = 2.01, 95% CI: 1.12-3.63). The effects of these variables remained after adjustment for other variables.