RESUMEN
A study was done to determine the efficacy of aqueous ozone treatment in killing Listeria monocytogenes on inoculated alfalfa seeds and sprouts. Reductions in populations of naturally occurring aerobic microorganisms on sprouts and changes in the sensory quality of sprouts were also determined. The treatment (10 or 20 min) of seeds in water (4 degrees C) containing an initial concentration of 21.8 +/- 0.1 microg/ml of ozone failed to cause a significant (P < or = 0.05) reduction in populations of L. monocytogenes. The continuous sparging of seeds with ozonated water (initial ozone concentration of 21.3 +/- 0.2 microg/ml) for 20 min significantly reduced the population by 1.48 log10 CFU/g. The treatment (2 min) of inoculated alfalfa sprouts with water containing 5.0 +/- 0.5, 9.0 +/- 0.5, or 23.2 +/- 1.6 microg/ml of ozone resulted in significant (P < or = 0.05) reductions of 0.78, 0.81, and 0.91 log10 CFU/g, respectively, compared to populations detected on sprouts treated with water. Treatments (2 min) with up to 23.3 +/- 1.6 microg/ml of ozone did not significantly (P > 0.05) reduce populations of aerobic naturally occurring microorganisms. The continuous sparging of sprouts with ozonated water for 5 to 20 min caused significant reductions in L. monocytogenes and natural microbiota compared to soaking in water (control) but did not enhance the lethality compared to the sprouts not treated with continuous sparging. The treatment of sprouts with ozonated water (20.0 microg/ml) for 5 or 10 min caused a significant deterioration in the sensory quality during subsequent storage at 4 degrees C for 7 to 11 days. Scanning electron microscopy of uninoculated alfalfa seeds and sprouts showed physical damage, fungal and bacterial growth, and biofilm formation that provide evidence of factors contributing to the difficulty of killing microorganisms by treatment with ozone and other sanitizers.
Asunto(s)
Listeria monocytogenes/efectos de los fármacos , Medicago sativa/microbiología , Ozono/farmacología , Gusto , Agua/química , Recuento de Colonia Microbiana , Relación Dosis-Respuesta a Droga , Microbiología de Alimentos , Germinación , Listeria monocytogenes/crecimiento & desarrollo , Medicago sativa/crecimiento & desarrollo , Medicago sativa/ultraestructura , Microscopía Electrónica de Rastreo , Oxidantes Fotoquímicos/farmacología , Semillas/microbiología , Semillas/ultraestructura , Gusto/efectos de los fármacos , Factores de Tiempo , Resultado del TratamientoRESUMEN
An antibacterial treatment consisting of 1.5% lactic acid plus 1.5% hydrogen peroxide at 40 degrees C for 15 min was effective in reducing foodborne bacterial pathogens on raw apples. However, the effects of this treatment on an apple's sensory characteristics and the extent of consumers' willingness to use the treatment at home were not known. This study was undertaken to determine the sensory acceptability and chemical characteristics (pH, soluble solids, and total acidity) of apples subjected to the sanitizing treatment and to obtain information on consumers' purchase behavior, apple handling and consumption practices, and willingness to use an antibacterial treatment. Untrained consumers (n = 80) evaluated the appearance, color, aroma, flavor, texture, and overall appeal of untreated (control) and treated Red Delicious apples that had been stored at 5 degrees C for 0, 6, and 10 days. Panelists used a nine-point hedonic scale (1 = "dislike extremely"; 5 = "neither like nor dislike"; 9 = "like extremely") to evaluate sensory acceptability. Treatment and storage had no significant effect on the appearance, color, or aroma of the samples. Flavor ratings ranged from 6.2 ("like slightly") to 7.0 ("like moderately"). There was no significant difference among any of the control and treated apples stored for 0 days or among those stored for 6 days. Although apples stored for 10 days received the lowest ratings (6.2 to 6.3), they still had an acceptable flavor (6, "like slightly"), and panelists could not perceive differences between the control samples and the treated samples on day 10. The same trends were noted in texture ratings and in overall liking ratings. Treatment and storage had a minimal effect on pH (range, 3.96 to 4.02), soluble solids (range, 11.8 to 12.9 degrees Brix), and total acidity (range, 0.20 to 0.23% malic acid), which are important for apple flavor. Many consumers (87%) were concerned about fruit safety, and 53.2% were willing to try an antibacterial treatment at home. However, 74% would not be willing to use it if a 15-min heating-and-soaking step were required. Implementation of the treatment may be more feasible in the packinghouse than in the home.
Asunto(s)
Desinfectantes/farmacología , Malus/microbiología , Comportamiento del Consumidor , Seguridad de Productos para el Consumidor , Humanos , Peróxido de Hidrógeno/farmacología , Concentración de Iones de Hidrógeno , Ácido Láctico/farmacología , Odorantes , GustoRESUMEN
A study was done to evaluate natural volatile compounds for their ability to kill Salmonella on alfalfa seeds and sprouts. Acetic acid, allyl isothiocyanate (AIT), trans-anethole, carvacrol, cinnamic aldehyde, eugenol, linalool, methyl jasmonate, and thymol were examined for inhibitory and lethal activity against Salmonella by exposing inoculated alfalfa seeds to compounds (1,000 mg/liter of air) for 1, 3, and 7 h at 60 degrees C. Only acetic acid, cinnamic aldehyde, and thymol caused significant reductions in Salmonella populations (>3 log10 CFU/g) compared with the control (1.9 log10 CFU/g) after treatment for 7 h. Treatment of seeds at 50 degrees C for 12 h with acetic acid (100 and 300 mg/liter of air) and thymol or cinnamic aldehyde (600 mg/liter of air) significantly reduced Salmonella populations on seeds (>1.7 log10 CFU/g) without affecting germination percentage. Treatment of seeds at 50 degrees C with AIT (100 and 300 mg/liter of air) and cinnamic aldehyde or thymol (200 mg/liter of air) did not significantly reduce populations compared with the control. Seed germination percentage was largely unaffected by treatment with gaseous acetic acid, AIT, cinnamic aldehyde, or thymol for up to 12 h at 50 degrees C. The number of Salmonella on seeds treated at 70 degrees C for 80 min with acetic acid (100 and 300 mg/liter of air), AIT (100 mg/liter of air), and cinnamic aldehyde and thymol (600 mg/liter of air) at water activity (a(w)) 0.66 was not significantly different than the number inactivated on seeds at a(w) 0.49. Acetic acid at 200 and 500 mg/liter of air reduced an initial population of 7.50 log10 CFU/g of alfalfa sprouts by 2.33 and 5.72 log10 CFU/g, respectively, within 4 days at 10 degrees C. whereas AIT at 200 and 500 mg/liter of air reduced populations to undetectable levels; however, both treatments caused deterioration in sensory quality. Treatment of sprouts with 1 or 2 mg of AIT per liter of air adversely affected sensory quality but did not reduce Salmonella populations after 11 days of exposure at 10 degrees C.
Asunto(s)
Desinfectantes/farmacología , Medicago sativa/microbiología , Salmonella/efectos de los fármacos , Semillas/microbiología , Recuento de Colonia Microbiana , Germinación , Salmonella/crecimiento & desarrollo , Intoxicación Alimentaria por Salmonella/prevención & control , Gusto , Temperatura , Factores de TiempoRESUMEN
Chicken (bone-in, skinless, split breast) injected with lemon-pepper poultry pump marinade containing 20 or 30% honey was compared with chicken (with and without skin) marinated without honey. The objectives were to 1) determine moisture and fat contents and instrumental color and texture measurements, 2) characterize the sensory profiles of marinated chicken baked with and without skin, and 3) investigate the effect of honey marinades on the sensory characteristics of chicken baked without skin. Chicken was roasted at 177 C for one h to an internal temperature of 80 C. A trained panel (n = 13) evaluated the roasted chicken. Results showed that skin could be removed from premarinated chicken breast before baking without significantly affecting the amount of marinade uptake, moisture content, fat content, texture (force required to shear), or most instrumental measurements of color. With regard to sensory characteristics, skin removal before baking resulted in a less glossy and moist appearance, less brown color, and more intense pepper flavor in the roasted product than when the skin was not removed. Addition of honey to the marinade restored, to some extent, the intensities of moist and glossy appearance and brown color that were reduced by removal of the skin before baking.
Asunto(s)
Culinaria , Miel , Aves de Corral , Piel , Animales , Grasas de la Dieta/análisis , Tecnología de Alimentos , Calor , SensaciónRESUMEN
Scallopini is a general name derived from scallopine, an Italian preparation of veal, which describes thinly pounded cuts of meat which are either used as a cutlet or rolled around other foods and cooked. Concept development was accomplished through use of focus groups, consumer ranking studies, and mailed surveys. The objective of this study was to assess consumer acceptability of chicken scallopini at various thicknesses (4, 8 and 12 mm) and concentrations (0, 1, and 2%) of added sodium tripolyphosphate (STPP). A 3 x 3 factorial design with three replications was adopted for use in this study. To assess consumer acceptability of packaged products, 53 participants were presented with three packages of the raw scallopini packaged on white styrofoam trays and overwrapped with film. Because STPP produces no visual change in the product at the levels used, only product thickness was varied. The mean price suggested by panelists from the sensory evaluation was $1.28/lb. The average price per pound suggested for the raw, packaged product was $1.62. For the attributes of overall acceptability, tenderness, juiciness, flavor, size, and texture, the mean ratings were high, indicating an acceptable product in any of the nine treatments. Sensory attributes were affected by STPP concentration but not by scallopini thickness. As STPP concentration increased, hedonic ratings for tenderness, texture, juiciness, flavor, overall acceptability, and purchase likehood increased. Purchase likelihood was rated highest for scallopini containing 2% STPP. Purchase likelihood was verified through use of a simulated supermarket simulation test.
Asunto(s)
Productos Avícolas/normas , Adulto , Química Física/métodos , Participación de la Comunidad , Comportamiento del Consumidor , Humanos , Polifosfatos/administración & dosificaciónRESUMEN
In a study of marketing opportunities for fresh, dark, chicken meat, focus group participants (n = 34) provided qualitative information concerning potential products and packaging concepts. Results of the focus groups indicated that the participants were willing to purchase new, convenient poultry products made from dark chicken meat. Specific dark meat products the participants were willing to by included boneless, skinless thighs, kabob cubes, and stir-fry strips. Consumers desired clear packaging for the products but did not want the packaging to be microwaveable or ovenproof. Acceptance of chicken kabob chunks and stir-fry strips of varying piece sizes (2.54, 3.81, and 5.08 cm) and seasoning concentrations (1.6, 2.1, and 2.6%) was evaluated by consumers (n = 83) using a nine-point hedonic scale. The most preferred products were a 5.08 cm (2 in) kabob with 2.6% seasoning and a stir-fry strip with 2.6% seasoning. A simulated supermarket setting test was conducted to verify findings from a mailed survey (n = 115) and actual purchase behavior by consumers (n = 121). A calculated desirability index indicated a ranked preference to be: breasts > kabobs > stir-fry > boneless, skinless thighs > bone-in, skin-on thighs.
Asunto(s)
Comportamiento del Consumidor , Culinaria , Carne , Adulto , Animales , Pollos , Femenino , Embalaje de Alimentos , Humanos , Masculino , Persona de Mediana Edad , Músculo Esquelético , Productos Avícolas , Análisis de Regresión , Factores Socioeconómicos , Encuestas y Cuestionarios , GustoRESUMEN
Large brown eye Kano white cowpea (Vigna unguiculata) seeds were processed into three batches of flour by wetting, drying individually at 30, 80, and 120 degrees C, decorticating and dry milling. Starch was extracted from the cowpea seed and protein from the flour using water as solvent. The water-extractable proteins were purified by dialysis and analysed by electrophoresis. The cowpea flour was used to produce akara balls (fried paste). The microstructure of the cowpea cotyledon, flour, starch and akara crumb were examined with a scanning electron microscope (SEM). Electrophoretic separation revealed that some of the protein fractions from the sample extracted from 30 degrees C dried cowpea were absent in the sample extracted from the 80 degrees C and 120 degrees C dried cowpeas or their quantities had decreased. In the SEM study, no difference was observed in the microstructure of the three flour samples except in the size and shape of the starch granules and particles of protein and cell wall material. The starch granules from the cowpea dried at 120 degrees C had surface defects. Cavities occurred in the cotyledons of the 80 and 120 degrees C dried cowpea seeds, some starch granules, protein matrix and sometimes the entire cell contents were lost from the cell. The protein sheet in the akara crumb became thicker as temperature increased to 80 and 120 degrees C.
Asunto(s)
Fabaceae/química , Manipulación de Alimentos , Plantas Medicinales , Semillas/química , Carbohidratos de la Dieta/análisis , Fabaceae/ultraestructura , Harina/análisis , Calor , Humanos , Microscopía Electrónica de Rastreo , Proteínas de Vegetales Comestibles/química , Desnaturalización Proteica , Semillas/ultraestructura , TemperaturaRESUMEN
Cowpeas (Vigna unguiculata L. Walp) are an important grain legume in East and West African countries as well as in other developing countries. The U.S. is the only developed country producing large amounts of cowpeas. High protein (18 to 35%) and carbohydrate (50 to 65%) contents, together with an amino acid pattern complementary to that of cereal grains, make cowpeas potentially important to the human diet from a nutritional standpoint. Despite their potential as an inexpensive source of protein and energy, cowpeas are underutilized in the U.S. and other industrialized countries. A simple technology for preparing cowpea flour would stimulate increased consumption of this legume. This paper reviews the status of cowpea flour production technologies and uses of cowpea flour in various food products.
Asunto(s)
Fabaceae/química , Harina/análisis , Manipulación de Alimentos/métodos , Plantas Medicinales , África Oriental , África Occidental , Aminoácidos/análisis , Carbohidratos de la Dieta/análisis , Proteínas en la Dieta/análisis , Análisis de los Alimentos , Humanos , Tamaño de la Partícula , Estados UnidosRESUMEN
A simulated supermarket setting (SSS) test was conducted to determine whether consumers (n = 126) would purchase irradiated poultry products, and the effects of marketing strategies on consumer purchase of irradiated poultry products. Consumer preference for irradiated poultry was likewise determined using a home-use test. A slide program was the most effective educational strategy in changing consumers' purchase behavior. The number of participants who purchased irradiated boneless, skinless breasts and irradiated thighs after the educational program increased significantly from 59.5 and 61.9% to 83.3 and 85.7% for the breasts and thighs, respectively. Using a label or poster did not increase the number of participants who bought irradiated poultry products. About 84% of the participants consider it either "somewhat necessary" or "very necessary" to irradiate raw chicken and would like all chicken that was served in restaurants or fast food places to be irradiated. Fifty-eight percent of the participants would always buy irradiated chicken if available, and an additional 27% would buy it sometimes. About 44% of the participants were willing to pay the same price for irradiated chicken as for nonirradiated. About 42% of participants were willing to pay 5% or more than what they were currently paying for nonirradiated chicken. Seventy-three percent or more of consumers who participated in the home-use test (n = 74) gave the color, appearance, and aroma of the raw poultry products a minimum rating of 7 (= like moderately). After consumers participated in a home-use test, 84 and 88% selected irradiated thighs and breasts, respectively, over nonirradiated in a second SSS test.
Asunto(s)
Comportamiento del Consumidor , Irradiación de Alimentos , Carne , Animales , Pollos , Femenino , Preferencias Alimentarias , Humanos , MasculinoRESUMEN
Cowpeas and peanuts are legumes of major dietary and economic importance. They are favored worldwide because of their palatability, contribution to nutritional status, and low cost as a protein source compared to animal protein. Flours processed from cowpeas and peanuts have unique physico-chemical and sensory properties when used in composite flour mixtures. Appropriate blends of cowpea and peanut flours to replace wheat flour in Chinese-type noodles, muffins, and tortillas were determined using modelling and optimization procedures. For noodles, 15% peanut flour and 8% cowpea flour supplementation produced an acceptable product with high protein content (21%). For wheat flour replacement in muffins, up to 43% cowpea and up to 44% peanut flours may be used. However, when wheat flour replacement is 50% or greater, cassava flour should comprise 56 to 72% of the blend with a few exceptions. In tortillas, 24% cowpea and 46% peanut flours produced products similar in quality characteristics to those made from 100% wheat flour. The systematic approach used in these studies is more efficient than the traditional substitution method to optimize sensory qualities of wheat-based products containing composite flours.
Asunto(s)
Arachis , Fabaceae , Harina , Plantas Medicinales , Triticum , Fenómenos Químicos , Química Física , Proteínas en la Dieta/administración & dosificación , Proteínas en la Dieta/análisis , Alimentos , Preferencias Alimentarias , SensaciónRESUMEN
Feather (keratinous) protein isolates containing 2.8 and 7.2% half-cystine were prepared. Solubility of the former increased to 100% between pH 6 and 12, whereas, that of the latter reached only 2.5% at pH 12. Tests showed that mixtures of sodium dodecyl sulfate and 2-mercaptoethanol were needed to completely solubilize the high half-cystine protein, and that sodium dodecyl sulfate alone or in combination with urea and/or 2-mercaptoethanol increased solubilization of the low half-cystine product. The rates of these reactions are further increased by heat. Dry heat denatured the low half-cystine isolate more readily than the high half-cystine product; moist heat denatured both at a similar rate. Gel electrophoretic properties were unique for each keratinous product. Only the low half-cystine isolate ahd desirable functional properties in that it formed thick, viscous mayonnaise-like emulsions and desirable foams. Functional properties of this isolate were improved dramatically by adjusting the pH from 5.0 to 8.2 or by a two-step change from pH 5.0 to 4.0 to 8.2. Apparent nitrogen digestibility of the two keratinous isolates was greater than 90% as measured by rat growth and by pepsin-HCl digestion.