Deep-fried Samples Research Articles

Impact of Cooking Methods on Sensory Evaluation and Nutritional Properties of Caterpillar Medicinal Mushroom Cordyceps militaris (Ascomycetes)

This study addresses the alterations in nutrients [calcium, iron, and vitamins C and E (VC and VE, respectively)] and cordycepin content, alongside its sensory appeal in <i>Cordyceps militaris</i>, subjected to five distinct cooking methods: boiling, steaming, roasting, microwaving, and deep-frying. A comparative analysis showed the notable decline in nutrient content across most cooking methods excluding deep-frying. In notable contrast, the content of VE was substantially amplified during deep-frying, thereby emphasizing its value in preserving nutrients. However, an exception was noted wherein VE content remained essentially unchanged in the microwaved samples. Notably, the cordycepin content in boiled <i>C. militaris</i> reduced significantly, contrastingly, an elevation in this content was recorded for steamed, microwaved, or deep-fried samples, with roasting producing a stable content comparable to raw samples. The principal component analysis further discerned the iron, VC, and cordycepin as primary influencers on raw and roasted <i>C. militaris</i>, signifying superior retention during roasting, whereas deep-fried samples were predominantly affected by the calcium and VE content. Observation on nutrient losses revealed that boiling, steaming, and microwaving were less efficacious, compared with roasting and deep-frying. Sensory evaluations inductively favored steaming as synonymous with the finest culinary attribute, whereas deep-frying ranked least favorably on the sensory scale. Consequently, the present study offers refined dietary advice for the consumption of <i>C. militaris</i> catered to specific demographic groups, deepening understanding of the effects of various culinary practices on its overall nutrient profile and organoleptic properties.

Aroma characterization and consumer acceptance of four cookie products enriched with insect (Ruspolia differens) meal

This research aims to advance knowledge on the impact of four processing methods on volatile compounds from insect-based baked products (cookies) to provide insights on consumer acceptance. Samples were exposed to double step enzyme digestive test, volatiles characterized through headspace analysis, while semi-trained panelists were recruited for the sensory test. Blanched and boiled samples of R. differens had considerably higher digestibility (83.42% and 81.61%, respectively) (p < 0.05) than toasted and deep-fried samples. Insect-based cookie products integrated with blanched and boiled R. differens meal expressed higher digestibility (80.41% and 78.73%, respectively) that was comparable to that of commercial cookie products (control cookies-CTRC with 88.22%). Key volatile compounds common between the various cookie products included, nonanal, octanal, methyl-pyrazine, hexanal, tetradecane, 2-pentylfuran, 2-heptanone, 2E-octenal, 2E-heptenal and dodecane. Among the volatile compounds, pleasant aromas observed were 2E,4E-dodecadienal, pentanal, octanal, methyl pyrazine, furfurals, benzaldehyde, and 2-pentyl furan, which were more pronounced in cookies fortified with boiled, toasted and deep-fried R. differens meal. There was a greater resemblance of sensory characteristics between control cookies and those fortified with deep-fried R. differens. These findings underscore the significant influence of aroma compounds on consumer acceptability and preference for insect-based baked food products, which allows for future process-modification of innate aromas of insect-based meals to produce high-valued pleasant consumer driven market products.

Microstructural and physicochemical changes of coated and frozen fried chicken

The objective of this study was to understand the microstructural and physicochemical changes of deep-fried chickens due to the application of a chicken protein-based edible coating, two types of oils (canola vs. corn oil), and frozen temperature (−18°C) over 60 days. The application of the edible coating was able to reduce the fat content and fat uptake significantly (p < .05). However, the fat content of corn oil deep-fried samples increased over storage time. The use of corn oil for frying resulted in higher puncture force and lower TBARS values (p < .05). Scanning electron microscopy showed that the application of the edible protein coating presented a smooth and intact surface morphology, especially for canola oil deep-fried samples. Fourier transform infrared spectroscopy results indicated that functional compounds in the oils were not affected by the edible coating. However, high heat during frying induced the formation of polar compounds and lipid oxidation. Novelty impact statement The results of this study demonstrated that the application of a protein-based edible coating prepared from the chicken could be used as a product-friendly coating to reduce the fat uptake in canola oil-fried chicken over frozen storage. Also, the type of oil that is used for frying influences many characteristics of deep-fried chicken including the oil content, lipid oxidation, and textural properties, particularly during frozen storage. Due to the high consumption of deep fat-fried foods and the importance of consumer health, it is crucial to select the frying medium wisely. In addition, this study may provide a viable solution for fat uptake reduction in the food industry.

Effects of Trehalose Content and Water Activity on the Fracture Properties of Deep-fried Wheat Flour Particles and Freeze-dried Porous Waxy Corn Starch Solids

Wheat flour-based batter containing 0 to 20 % trehalose was deep-fried, dried and held in various water activity (aw) conditions. The effects of trehalose content and aw on oil content, water sorption, isothermal mechanical relaxation, and fracture properties were investigated. For comparison, the fracture properties of freeze-dried porous waxy corn starch solids were also investigated. The 10 % trehalose sample had the lowest oil content, water content, and aw. A force-reduction value (∆F) of the samples was evaluated as a typical mechanical relaxation parameter. ∆F gradually increased with increasing aw and sharply increased above a specific aw presumed to be associated with the glass to rubber transition. Compared to ∆F values among the glassy samples, 10 and 20 % trehalose samples had higher ∆F values (were more rigid) than 0 and 5 % trehalose samples. From the fracture measurements of the glassy samples, the first fracture force increased linearly and the number of fracture peaks decreased linearly with increasing aw. At each aw, 10 % trehalose had the lowest first fracture force and the highest the number of fracture peaks. Freeze-dried porous waxy corn starch solids showed similar fracture properties to deep-fried samples. These findings suggest that around 10 % trehalose content is optimal for producing deep-fried foods with a brittle texture.

Influence of process parameters on the physico-chemical and microstructural properties of rice crackers: A case study of novel spray-frying technique

The physico-chemical and microstructural properties of fried rice crackers were studied as a function of spray-frying. Fried rice crackers were produced using the spray- and deep-frying techniques and their moisture content, oil uptake, color, texture (i.e., hardness, expansion ratio, and bulk density), and microstructure were compared. For spray-frying, the heat distribution inside the frying chamber, the effects of spraying rate of oil (0.3, 0.5, and 0.7 L/s), and spinning speed of the frying basket (60, 80, and 100 rpm) were evaluated. Although the average temperature varied at each depth of the fryer, it did not influence overall heat distribution. Results also revealed that higher spraying rate and spinning speed resulted in higher moisture loss, higher oil uptake, darker color, and less crispiness. Compared with deep-frying, the oil uptake of spray-fried samples was lower by 45.4%. The color of the spray-fried crackers was better than that of the deep-fried samples. SEM micrographs showed that the cellular structure and integrity of the cell wall of deep-fried rice crackers were more deformed. They also had larger pore diameter and deeper and larger cavities, leading to higher oil content and crispier texture than spray-fried samples. Rice crackers fried using a spraying rate of 0.7 L/s and spinning speed of 100 rpm resulted in the most desirable physico-chemical qualities. Although the texture properties of the resulting rice crackers could still be improved, spray-frying could be an alternative technique in producing high-quality rice crackers with very low oil content.

Chicken processing by-product: A source of protein for fat uptake reduction in deep-fried chicken

Chicken processing generates large quantities of by-products which can be used a source of protein for fat uptake reduction in fried chicken industry. This study investigated the use of edible coating prepared from chicken protein (CP) recovered using isoelectric precipitation/solubilization (ISP) from chicken drumstick processing by-products as a fat blocker in deep-fat fried chicken drumsticks samples. The samples were coated with edible coating at three different CP concentrations 5, 10, or 15% w/w and subsequently dipped in batter and breaded prior to deep frying. Deep-fat fried samples without edible coating served as control. The samples were deep-fried at 177 °C for 3–4 min. Proximate composition, pH, texture, frying yield and sensory properties of the samples were tested. Total fat content of deep-fried samples with 15% coating showed the lowest amount of absorbed fat, about 60% less than the control. No difference was found between the color, pH and sensory properties of the coated and uncoated samples. However, uncoated samples were harder than coated samples. Also, samples coated with coating had higher moisture content and frying yield after frying, compared to uncoated samples. The development of low-fat fried foods using this approach would allow consumers to enjoy the taste and texture that is characteristic of fried food. At the same time, the food industry can reduce the environmental issues due to disposal of chicken processing by-products. The use of chicken proteins as an edible coating on fried chicken is novel and product friendly.

Effects of trehalose and corn starch on the mechanical glass transition temperature and texture properties of deep-fried food with varying water and oil contents

The effects of trehalose and corn starch on the mechanical glass transition temperature (Tg) and texture properties of a deep-fried sample (particles of deep-fried batter) with varying water and oil contents were investigated. Tg decreased linearly with increases in both water and oil contents, attributable to their plasticizing effects. Tg was elevated by the addition of trehalose, likely due to its anti-plasticizing effect. Corn starch had a negligible effect on Tg. The critical water content and water activity (water content and water activity at Tg = 25 °C) were determined by extrapolation, and obtained values were validated by isothermal mechanical relaxation. The texture of the samples changed from brittle to ductile near the critical water content and water activity. The trehalose-added sample maintained a brittle texture at a higher water content than the non-additive and corn starch-added samples, as trehalose elevated the critical water content of the deep-fried samples.

Effect of water sorption on the glass transition temperature and texture of deep-fried models

The purpose of this study was to understand effect of water sorption on the glass transition temperature (Tg) and texture of deep-fried models, namely, bits of deep-fried tempura batter. Two types of deep-fried models (normal and glucose-added samples) were employed. Tg was investigated by thermal rheological analysis (TRA); although TRA measurements for pellet samples showed an unclear glass transition, the measurements for bulk samples showed a large force-drop induced by this effect. Isothermal mechanical relaxation measurement confirmed that the Tg value of the deep-fried samples could be evaluated from the departure point of the force-drop. The Tg decreased with increase in water content because of the water plasticizing effect; the glucose-added sample had a higher Tg than the normal sample at each water content. The fracture property of the samples changed from brittle to ductile at the critical water content and/or water activity (i.e., those at Tg = 25 °C).

다양한 조리법에 따른 버섯류의 엽산 리텐션

This study was performed to investigate the effects of different cooking methods (boiling, roasting, stir-frying, and deep-frying) on folate retention in 6 kinds of mushrooms (Beech-, button-, Juda’s ear-, oak-, oyster-, and winter-mushrooms) frequently consumed in Korea. In order to assure reliability of analytical data, trienzyme extraction-L casei method was verified and analytical quality control was also evaluated. Folate contents of mushrooms varied by 6.04-64.82 g/100 g depending on the type of mushrooms. and were significantly affected by cooking methods. Depending on cooking methods, folate contents of mushrooms decreased by 22-48%, 2-31%, and 17-56% for Juda’s ear-, oak- and oyster-mushrooms, respectively, while 17-90% of folate was increased in Beech mushroom. Overall, the largest weight loss was found in boiled mushrooms, but the lowest one in deep-fried samples. True folate retention rates considering processing factor were less than 100% for all cooked mushrooms except for Beech samples. Overall, folate loss was the largest by boiling with water but the smallest by deep-frying. Both accuracy and precision of trienzyme extraction-L-casei method were excellent based on a recovery close to 100% and coefficient variations less than 3%. Quality control chart of folate analysis (n=26) obtained during the entire study and an international proficiency test (z-score=-0.5) showed that trienzyme extraction-L casei method is reliable enough for production of national folate database.

Dietary acrylamide: What happens during digestion

Acrylamide is a well-known potentially carcinogen compound formed during thermal processing as an intermediate of Maillard reactions. Three objectives were addressed: the impact of gastric digestion on acrylamide content of French Fries, chips, chicken nuggets, onions rings, breakfast cereals, biscuits, crackers, instant coffee and coffee substitute; the acrylamide content evolution during gastrointestinal digestion of French fries and chips; and the effectiveness of blanching and air-frying on acrylamide mitigation after gastrointestinal digestion.A significant increase (p-value <0.05) in acrylamide content was observed for most of the products after gastric digestion (maximum registered for sweet biscuits, from 30±8 to 150±48µg/kg). However, at the end of the intestinal stage, acrylamide values were statistically similar (p-value=0.132) for French fries and lower than the initial values (before digestion) in potato chips (p-value=0.027). Finally, the low acrylamide content found in blanched and air-fried samples, remained still lower than for deep fried samples even after gastrointestinal digestion.

EFFECT OF DIFFERENT COOKING METHODS ON CHANGES OF FREE FATTY ACIDS, THIOBARBITORIC ACID, HEAVY METAL (NI, CR, CO, CD, PB) AND SENSORY PROPERTIES OF GRASS CARP (CTENOPHARYNGODONIDELLA)

Introduction: Grass carp (Ctenopharyngodonidella, family Cyprinidae) is one of the main fresh water fish species and highly demanded aquaculture species in Iran. Among the cultivated fish, grass carp, also called farmed white fish, has received great attention because of its similarity to Caspian white fish in Iran. The muscle of fish contains important levels of nutrients which are beneficial to health. Most research has been done and published on raw flesh. Cooking can lead to a loss of the nutritional value of foods. In this case the preservation of the maximum nutritive value can be ensured by using correct methods of cooking. The aim of this research was the influence of five cooking methods (poaching, boiling, microwave pan- frying and deep- frying) on changes of free fatty acids, thiobarbitoric acid, heavy metal (Ni, Cr, Co, Cd, Pb) and sensory properties of grass carp (Ctenopharyngodonidella)fillets was evaluated. Materials and method: Grass carpsamples were purchased from a local market in Khorramshahr city, Khuzestan province, Iran. The fish were kept alive and transported to thelaboratory. On arrival,tsamples were washed and eviscerated. The samples were filleted and cut into slices (100 g each). The fish samples were cooked using AOAC 976.16 procedure (method for cooking seafood). Five common cooking procedures were selected: poaching in stainless steel pot of boiling water for 30 min and 30 s, steaming in stainless steel steamer for 5 min and 30 s, microwaving in microwave for 40 s, pan-frying (without oil) in frying pan for 6 min at 180 oC and deep-frying in olive oil in a deep fryer for 5 min at 180 oC. After the cooking process, the samples were cooled to room temperature and the skin and backbone of the samples were removed. All fish in each lot were homogenized using a kitchen blender and analyzed to determine free fatty acid, thiobarbitoric acid, heavy metal and sensory properties. All sample homogenates were assayed in triplicate. Results and discussion: The results indicated that the cooking methods of pouching, microwave and deep-frying increased thiobarbitoric acid (TBA), while cooking methods of boiling and pan- frying did not change TBA. The free fatty acid (FFA) content of the fillets was significantly reduced by the different cooking methods. The Ni in the cooking methods of boiling, pan- frying and deep- frying was not detected. The Cr in the cooking method of deep-fried samples was significantly decreased. The Co concentrations were below limits of detection in all samples. The Cd was only detected in microwave samples. The Pb content increased during cooking of fillets. The results of sensory properties were showed that the texture, odour, flavor, colour and overall likeness properties improve likeness score to some extent in deep-frying method and there were not significantly different between boiling, poaching and pan-frying.

Antioxidant action of ganghwayakssuk (Artemisia princeps Pamp.) in combination with ascorbic acid to increase the shelf life in raw and deep fried chicken nuggets

Raw and deep fried chicken nuggets containing various levels of ganghwayakssuk ethanolic extract (GE) in combination with ascorbic acid (Aa) were evaluated for shelf-life during refrigerated storage (4°C). The pH and color (lightness, redness, and yellowness) values of raw and deep fried samples were significantly affected by the addition of GE (P<0.05). All antioxidant combinations except for Aa+GE 0.01 were effective at delaying lipid oxidation (CD, POV, and TBARS) when compared to the control or Aa. Raw samples with GE 0.2 and Aa+GE 0.1 exhibited lower bacterial populations during storage. The sensory characteristics (color, juiciness, flavor, tenderness, and overall acceptability) did not differ significantly in all deep fried chicken nugget samples, except color, whereas storage time had a significant effect (P<0.05). The results suggest the possibility of utilizing raw and deep fried chicken nuggets with a mixture of ganghwayakssuk and ascorbic acid for the increase of shelf-life and quality.

Quantification of furanic compounds in coated deep-fried products simulating normal preparation and consumption: Optimisation of HS-SPME analytical conditions by response surface methodology

The validation of a method for the simultaneous quantification of furanic compounds in coated deep-fried samples processed and handled as usually consumed is presented. The deep-fried food was grinded using a device that simulates the mastication, and immediately analysed by headspace solid phase microextraction coupled to gas chromatography–mass spectrometry. Parameters affecting the efficiency of HS-SPME procedure were selected by response surface methodology, using a 23 full-factorial central composite design. Optimal conditions were achieved using 2g of sample, 3g of NaCl and 40min of absorption time at 37°C. Consistency between predicted and experimented values was observed and quality parameters of the method were established. As a result, furan, 2-furfural, furfuryl alcohol and 2-pentylfuran were, for the first time, simultaneously detected and quantified (5.59, 0.27, 10.48 and 1.77μgg−1 sample, respectively) in coated deep-fried fish, contributing to a better understanding of the amounts of these compounds in food.

Methodological developments in crispness assessment: Effects of cooking method on the crispness of crusted foods

A new method was developed to assess the texture of crispy-crusted foods with a soft, high-moisture core. This method, applied to commercial pre-cooked chicken nuggets, combines characteristics derived from the force/displacement curves of the whole sample with characteristics of the simultaneously emitted sound. The use of a not-sharp blade probe to perform the test proved to be an effective technique for characterizing the texture of chicken nuggets after different final cooking processes. The force curves of the samples differed with the cooking process. Deep-fried samples and those cooked in a conventional oven presented jagged force curves and acoustic signals with many peaks, both characteristics of crispy products. The curve profiles of microwaved samples were drastically different and typical of tough, gummy products. The use of a susceptor package in microwave heating improved the crispness of the samples. The number of sound peaks was the acoustic parameter that best discriminated between the samples. It was found that although the moisture and fat contents of the core and crust are closely related to the texture characteristics, samples with similar water contents can have very dissimilar crispness characteristics. The fat content of the core did not change significantly with the final cooking process in any of the samples.