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Deep-fat frying is a unit operation which develops unique sensorial attributes in foods. For instance, texture is the principal quality parameter of tortilla and corn chips. On the other hand, computer vision is a useful tool for quality evaluation and prediction of some physical properties in different either raw or processed foods. The objective of this research was to characterize corn and tortilla chips by using computer vision, and to build proper mathematical models which permit to predict mechanical properties of these chips (maximum force, such as hardness, and distance to maximum force, such as toughness) by using chromatic features extracted from their corresponding digital images. Corn and tortilla chips (thickness of 2 mm; diameter of 37 mm) were made from masa of maize and fried at constant oil temperatures of 160, 175, and 190 °C. A high linear correlation (R2 > 0.9400) was obtained between mechanical properties and some image features (Hu, Fourier, and Haralick moments). Cross-validation technique demonstrated the repeatability and good performance (>90%) of the models tested, indicating that can be used to predict the textural properties of the tortilla and corn chips by using selected features extracted from their digital images, without the necessity of measuring them in a texture analyzer.

Fusarium moniliforme Sheldon occurs worldwide on corn intended for human and animal consumption. A closely related species Fusarium proliferatum also occurs frequently on corn. Yellow dent corn, white dent corn, white and yellow popcorn and sweetcorn may be contaminated. Both organisms are capable of producing a group of toxins known as fumonisins, of which Fumonisin B1 (FB1), Fumonisin B2 (FB2) and Fumonisin B3 (FB3) are most common. Fumonisins have been found in corn and corn-based foods worldwide. Fumonisins may be found in sound whole kernel corn at levels at or below 1.0 μg/g. By contrast animal disease problems begin to occur at fumonisin levels above 5.0 to 10.0 μg/g. Corn-based food products that have the most frequent and highest fumonisin levels, besides whole kernels, are corn meal and corn grits. In the United States, corn meal has been found contaminated with Fumonisin B1 at levels from 0.5 to 2.05 μg/g, and grits from 0.14 to 0.27 μg/g. Corn flakes, corn pops, corn chips and tortilla chips have been found negative for fumonisins. Popcorn, sweetcorn and hominy corn have been found contaminated with sporadic, low levels (0.01 to 0.08 μg/g) of fumonisins. The effects of processing on fumonisins in corn are still largely unknown. Heating may cause a loss of fumonisins in corn, but it may be a loss of detectability rather than degradation.

Background: The modern food supply is often dominated by a large variety of energy dense, softly textured foods that can be eaten quickly. Previous studies suggest that particular oral processing characteristics such as large bite size and lack of chewing activity contribute to the low satiating efficiency of these foods. To better design meals that promote greater feelings of satiation, we need an accurate picture of the oral processing characteristics of a range of solid food items that could be used to replace softer textures during a normal hot meal. Aim: The primary aim of this study was to establish an accurate picture of the oral processing characteristics of a set of solid savoury meal components. The secondary aim was to determine the associations between oral processing characteristics, food composition, sensory properties, and expected satiation. Methods: In a within subjects design, 15 subjects consumed 50 g of 35 different savoury food items over 5 sessions. The 35 foods represented various staples, vegetables and protein rich foods such a meat and fish. Subjects were video-recorded during consumption and measures included observed number of bites, number of chews, number of swallows and derived measures such as chewing rate, eating rate, bite size, and oral exposure time. Subjects rated expected satiation for a standard 200 g portion of each food using a 100 mm and the sensory differences between foods were quantified using descriptive analysis with a trained sensory panel. Statistical analysis focussed on the oral processing characteristics and associations between nutritional, sensory and expected satiation parameters of each food. Results: Average number of chews for 50 g of food varied from 27 for mashed potatoes to 488 for tortilla chips. Oral exposure time was highly correlated with the total number of chews, and varied from 27 s for canned tomatoes to 350 s for tortilla chips. Chewing rate was relatively constant with an overall average chewing rate of approximately 1 chew/s. Differences in oral processing were not correlated with any macronutrients specifically. Expected satiation was positively related to protein and the sensory attributes chewiness and saltiness. Foods that consumed in smaller bites, were chewed more and for longer and expected to impart a higher satiation. Discussion: This study shows a large and reliable variation in oral exposure time, number of required chews before swallowing and expected satiation across a wide variety of foods. We conclude that bite size and oral-sensory exposure time could contribute to higher satiation within a meal for equal calories.

When the baked chip was immersed in the fryer, oil immediately coated and clung to the surface and began to move into the chip. As heat built up within the chip, the moisture turned to steam and exited the chip leaving behind a sponge-like network of tunnels which became filled with oil. The transformations occurred within 20 sec. As frying time increased, (1) starch granules with strong birefringence remained on the surface of the chip, (2) starch granules lost birefringence within the chip, and (3) the interior of the chip became smooth and plastic in appearance as protein, starch and lipids interacted to form a continuous phase that hardened upon dehydration.

Protein solubility, molecular weight distribution and pepsin-digestibilities of tortilla chips prepared from quality protein maize (QPM), regular maize and sorghum kernels were determined. QPM products contained higher amounts of extractable albumins plus globulins than regular maize and sorghum. Tortilla chip preparation decreased the solubility of proteins in salt-water (albumins plus globulins) and alcohol (prolamins) and increased the amount of unextractable proteins. Polyacrylamide gel electrophoresis in the presence of sodium dodecylsulfate exhibited fewer bands for albumins plus globulins in all grains and for prolamins in sorghum. Processing all grains into tortilla chips decreased protein digestibilities as estimated using the pepsin assay. Sorghum was the cereal most negatively affected by processing and possessed the lowest protein digestibility.

The phytochemical profiles (total phenolics, anthocyanins, ferulic acid, carotenoids) and antioxidant activities of five types of corn (white, yellow, high carotenoid, blue, and red) processed into masa, tortillas, and tortilla chips were studied. The nixtamalization process significantly (p < 0.05) reduced total phenolics and antioxidant activities when compared to raw grains. Nixtamalized grains exhibited higher concentration of free phenolics and soluble conjugated ferulic acid and had lower concentrations of bound phenolics and ferulic acid than unprocessed grains. Among processed products, there was little difference in the phytochemical contents and antioxidant activities. Among types of corn, the highest concentrations of total phenolics, ferulic acid, and antioxidant activity were observed in the high-carotenoid genotype followed by the regular yellow counterpart. The white corn contained the lowest amount of total phenolics and antioxidant activity. The pigmented blue corn had the highest anthocyanin concentration followed by the red counterpart. These findings suggest that lime-cooking significantly reduced the phytochemical content of nixtamalized products but released phenolics and ferulic acid.

Methods Patients from Southern Romania with grass pollen rhinitis, diagnosed by allergy evaluation with positive skin prick tests and high serum levels of specific IgE to Pooideae pollen, were screened for food allergy by detailed clinical history of symptoms related to maize-derived edible products, including foods with corn as basic ingredient, such as polenta, porridge, cornflakes, tortilla chips, popcorn, canned kernels, or traditional products, such as stigmas and corncob leaves with pollen deposition. Patients with occupational exposure to maize flour or pollen were not included, and ceremonial use of oral corn pollen in the Romanian Plain was not reported. We assessed the IgE sensitization profile to pollen allergen components used as biomarkers of Pooideae allergy by a novel multiparameter immunoblot test system.

Virtually eliminating the amount of trans fatty acids in industrially produced food could avert between 72 000 (6% of the total) and 228 000 (19%) coronary heart events each year in the United States, a new US and Dutch review study concludes ( N Engl J Med 354;1601-13). The amount of trans fats in packaged snack foods, bakery products, deep fried fast food, margarine, and packaged snacks such as tortilla chips increases consumers' risk of cardiovascular disease, coronary heart disease, and sudden death from cardiac causes, say the researchers, from Brigham and Women's Hospital and Harvard Medical School and the Harvard School of Public Health in …

This case is designed to illustrate the methods that small-business lenders use to evaluate the creditworthiness of potential commercial borrowers. It is set in South Central Los Angeles, the commercial loan officer is of Mexican descent, and the potential borrowers are Mexican immigrants. The unique setting allows students to evaluate the creditworthiness of the borrower, while discussing many of the nonfinancial considerations that accompany the lending process. The case explores several issues, including immigration, urban development, and the challenges facing mainstream banks trying to expand into new markets.

2,5-Dimethyl-4-hydroxy-3(2H)-furanone (DHF) was identified (GC−MS) in canned, frozen (cooked), and fresh (cooked) sweet corn. It was also identified in corn tortilla chips and taco shells. The concentration of DHF was higher in canned (170−270 μg/kg) than in fresh (19 μg/kg) or frozen (27 μg/kg) sweet corn. Moderate concentrations of DHF occurred in tortilla chips (260 μg/kg) and taco shells (80 μg/kg). The DHF was isolated using a dynamic headspace method with anhydrous sodium sulfate blended with the corn products to remove water. DHF occurred at a concentration on the order of 5−10 times its odor threshold (in water) in the canned sweet corns and tortilla chips and also above this threshold in taco shells. Keywords: 2,5-Dimethyl-4-hydroxy-3(2H)-furanone; Furaneol; sweet corn; tortilla chips; identification; concentration; dynamic headspace; sodium sulfate

Genetically modified (GM) foods have caused many controversies. One important controversy relates to tolerance?the impurity rate that is tolerated before a commodity must be labeled as genetically modified. Currently, the United States does not have a specific tolerance or threshold level for GM foods. This paper uses experimental auctions to determine consumers? acceptance of non-GM foods with zero, 1 percent, and 5 percent tolerance for genetically modified material. Our results indicate that consumers would pay less for food that tolerates GM material, but the discount is not significantly different for foods with 1-percent and 5-percent GM content. Key words: genetically modified (GM) foods, contamination thresholds, laboratory auctions, nth-price auction, vegetable oil, tortilla chips, russet potatoes

Public debate continues over whether the United States should regulate genetically modified (GM) foods by imposing a mandatory labeling policy. This paper develops a model that shows that a voluntary GM-labeling policy results in higher welfare than a regulated mandatory GM-labeling policy, if consumers can accurately read the signals in each market. We then develop an experiment that shows consumers behave as if they can accurately identify signals for GM foods. Our model and results support the perspective that the United States has been prudent in fending off calls for regulations demanding a mandatory GM-labeling policy.

Public debate continues over whether the United States should regulate genetically modified (GM) foods by imposing a mandatory labeling policy. This paper develops a model that shows that a voluntary GM-labeling policy results in higher welfare than a regulated mandatory GM-labeling policy, if consumers can accurately read the signals in each market. We then develop an experiment that shows consumers behave as if they can accurately identify signals for GM foods. Our model and results support the perspective that the United States has been prudent in fending off calls for regulations demanding a mandatory GM-labeling policy.

Genetically modified (GM) foods have caused many controversies. One important controversy relates to tolerance - the impurity rate that is tolerated before a commodity must be labeled as genetically modified. Currently, the United States does not have a specific tolerance or threshold level for GM foods. This paper uses experimental auctions to determine consumers' acceptance of non-GM foods with zero, 1 percent, and 5 percent tolerance for genetically modified material. Our results indicate that consumers would pay less for food that tolerates GM material, but the discount is not significantly different for foods with 1-percent and 5-percent GM content.

The fate of fumonisin B(1) (FB(1)), a mycotoxin found in corn, during the commercial manufacture of fried tortilla chips was studied. FB(1) and hydrolyzed FB(1) (HFB(1)) concentrations in four lots of corn and in the masa, other intermediates, liquid and waste byproducts, and fried chips were determined by HPLC. FB(1) concentrations in the masa and chips were reduced significantly, up to 80% in the fried chips, compared to that in the raw corn. HFB(1) was also found in the masa and chips, but at low concentrations compared to FB(1). LC-MS analyses corroborated HPLC findings and further showed the presence of partially hydrolyzed FB(1) (PHFB(1)), which, like HFB(1), was formed during the nixtamalization (cooking/steeping the corn in alkaline water to make masa) step and found predominantly in the cooking/steeping liquid and solid waste. No significant amounts of N-(carboxymethyl)-FB(1) or N-(1-deoxy-D-fructos-1-yl)-FB(1), indicative of fumonisin-sugar adduct formation, were found. Thus, FB(1) is removed from corn and diverted into liquid and waste byproducts during the commercial production of fried tortilla chips. Nixtamalization and rinsing are the critical steps, whereas grinding, sheeting, baking, and frying the masa had little effect.

instantáneas para preparación de frituras de masa y tortillas. Durante el proceso de elaboración de harinas instantáneas la menor variación en color se observó en las muestras adicionadas con cal. La mayor capacidad de absorción de agua correspondió a las muestras procesadas sin cal. La cohesión y adhesión de masas de harinas instantáneas preparadas con cal por cocimiento dieléctrico se sitúan dentro de los valores reportados para muestras de masa de nixtamal y de harinas comerciales de maíz nixtamalizado. El análisis de color en frituras elaboradas con harinas instantáneas preparadas con cocimiento dieléctrico mostraron ligeros cambios con relación a las frituras elaboradas por el proceso tradicional de nixtamalización. Las frituras de tortilla preparadas con harinas instantáneas (adicionadas de cal) con 15 minutos de cocimiento dieléctrico, presentaron valores de DE similares al control. El contenido de humedad de las frituras varió en un rango de 1.5 a 2.8. Las frituras de masa de harinas instantáneas preparadas por cocimiento dieléctrico adicionadas de cal absorbieron la mayor cantidad de aceite, seguidas por el control y finalmente por las muestras de frituras de tortilla. Las frituras de tortilla preparadas con harinas instantáneas (adicionadas con cal) durante 10 y 15 minutos con cocimiento dieléctrico fueron crujientes y suaves. Las harinas instantáneas elaboradas por cocimiento dieléctrico de maíz integral presentan un alto potencial para producir frituras de buenas características funcionales con ahorros substanciales en gasto de agua, tiempos de procesamiento y mayores rendimientos debido al uso integral del grano de maíz. Application of dielectric cooking to produce instant maize flour for corn and tortilla chips. This present work reports on the evaluation of a method for producing of instant flour for corn and tortilla chips based on dielectric cooking (DC). The samples prepared with lime showed a smaller variation in color than those without lime. A greater water absorption capacity was found in the samples processed without lime. The values for cohesion and adhesion of the DC masa prepared with lime are within the range of values previously reported for samples of masa prepared with nixtamal and commercial instant maize flours. The color analyses of chips from DC masa showed slight changes in relation to the chips prepared by the traditional process of nixtamalization. The DC tortilla chips (plus lime) with 15 minutes of DC showed similar values of DE as compared to the control (commercial tortilla chips). The moisture of the DC chips varied in the range from 1.5 to 2.8. The DC tortilla chips with lime absorbed a lower amount of oil than the control sample and the corn chips. In fact, the DC chips absorbed lower amount of oil as compared to the control. The DC tortilla chips with lime and processed for 10 and 15 minutes were crunchy and smooth. Dielectric cooking displays a high potential for corn and tortilla chips with good functional characteristics, giving substantial savings of water, processing time and with higher yields due to the use of the whole grain.

A method for the simultaneous determination of fumonisin B(1) (FB(1)) and its major hydrolysis product (HFB(1)), which is known to be formed during alkaline treatment of fumonisin-containing corn meal, was devised to analyze the levels of these mycotoxins in corn products available on the German market. Liquid chromatography/electrospray mass spectrometry in combination with selected ion monitoring (SIM) was used for unambiguous detection of FB(1) and HFB(1) after extraction of samples with acetonitrile/methanol/water (25:25:50) and solid-phase C18 cleanup. Quantitation was carried out using labeled fumonisin FB(1)-D(6) as an internal standard. The detection limits achieved with this method were 8 ng/g for HFB(1) (signal-noise ratio = 5:1) and 5 ng/g for FB(1) (s/n = 5:1) using the protonated molecule signals m/z 406 and 722 in the SIM mode. A screening of several corn-containing foodstuffs, among them extrusion products and alkali-processed corn food such as tortilla chips, showed HFB(1) and FB(1) contamination with levels of 8-80 and 5-450 ng/g, respectively.

Fusarium moniliforme Sheldon occurs worldwide on corn intended for human and animal consumption. A closely related species Fusarium proliferatum also occurs frequently on corn. Yellow dent corn, white dent corn, white and yellow popcorn and sweet corn may be contaminated. Both organisms are capable of producing fumonisins, including Fumonisin B1 (FB1), Fumonisin B2 (FB2) and Fumonisin B3 (FB3). Fumonisins have been found in corn and corn based foods worldwide. Fumonisins may be found in sound whole kernel corn at levels at or below 1.0 μg/g. By contrast animal disease problems begin to occur at fumonisin levels above 5.0 to 10.0 μg/g. Corn based food products that have the most frequent and highest fumonisin levels, besides whole kernel corn, are corn meal, corn flour and corn grits. In the U.S., corn meal and flour have been found contaminated with FB1 at levels from 0.5 to 2.05 μg/g, and grits from 0.14 to 0.27 μg/g. Corn flakes, corn pops, corn chips and tortilla chips have typically been found negative when tested for fumonisins. Popcorn, sweet corn and hominy corn have been found contaminated with sporadic, low levels (0.01 to 0.08 μg/g) of fumonisins. Contamination levels of corn based foods in Europe appear to be similar to slightly lower than similar products in the U.S., with the possible exception of Italy, where their corn hybrids and corn-based foods appear to be more frequently contaminated with higher levels of fumonisins.