CAROTENOID RETENTION AND SENSORY CHARACTERISTICS OF SELECTED VEGETABLES PREPARED BY INDUCTION STIR‐FRYING*

ABSTRACT

The effects of induction stir‐frying on carotenoid retention and sensory characteristics of selected vegetables (carrot, green spring onion, red pepper, snow pea, white spring onion and yellow pepper) were investigated. Cooking times ranged from 4 to 6 min, and cooking yields from 70.9 to 92.0%. The stir‐fried vegetables retained (w/w) more than 85% (mean) of each of their carotenoids (β‐carotene, lutein, zeaxanthin, α‐carotene, β‐cryptoxanthin and lycopene). Over three‐quarters of the 78 consumer panelists reported liking extremely/liking very much or liking moderately/liking slightly the appearance, color, flavor, texture and overall acceptability of carrot, green spring onion, red pepper, snow pea and yellow pepper; whereas, half to three‐quarters reported similarly for white spring onion. Few differences in attribute responses were observed by gender. Induction stir‐fried vegetables had excellent carotenoid retention, and the consumer panelists indicated liking them slightly to extremely.

PRACTICAL APPLICATIONS

This study indicates that vegetables that are cooked by induction stir‐frying retained (w/w) over 85% of their carotenoid content and had sensory characteristics that the consumer panelists liked. Perhaps individuals, specifically college students, might be inclined to consume more cooked vegetables if they liked the appearance, color, flavor, texture and overall acceptability of the vegetables. Consuming vegetables containing higher amounts of the carotenoids may also be beneficial.

     

PHYSICAL AND SENSORY CHARACTERISTICS OF COMMERCIALLY AVAILABLE FRANKFURTERS

This study's objective was to identify the range of physical and sensory properties of commercially available frankfurters. Twenty-five types of frankfurters were evaluated by a six-member sensory panel and subjected to Instron texture profiling. A wide range of sensory and textural characteristics was observed for acceptable frankfurters. Salty flavor and juiciness were correlated with fat content, but salt and fat content were inversely correlated. Negative correlations occurred between fat content and Instron fracturability and compression; fat content decreased resistance to force from mechanical stress. Firmness was positively correlated with Warner-Bratzler shear force. The development of an accurate regression equation to predict sensory hardness was not possible with this data set.     

VOLATILE COMPOUNDS AND SENSORY CHARACTERISTICS OF FRYING FATS

Oxidation-derived volatiles in French fries were evaluated relative to sensory characteristics of the fries and of the frying oils (low linolenic acid soybean oil, LLA; creamy partially hydrogenated soybean oil, CPH; liquid low linolenic acid hydrogenated soybean oil, LLH; and liquid partially hydrogenated soybean oil, LPH) in which they were fried. Hexanal concentration in French fries increased as oil use time increased for all fats; LLA and CPH produced higher hexanal concentrations in French fries after 10 and 15 days of oil use than did LPH and LLH. Hexanal concentration was negatively correlated with overall odor quality of French fries and positively correlated with grassy, rancid, painty, and chemical odor. Buttery, sweet, and French fry odor decreased and grassy, rancid, painty, and acrolein odor increased as oil use time increased.     

EARLY GENERATION SCREENING OF NAVY BEAN BREEDING LINES BY CANNING QUALITY ASSESSMENT AND PASTING CHARACTERISTICS OF BEAN FLOUR

Two methods (direct and indirect) were developed to screen small samples of bean seeds for their canning potential. Both methods were determined to be suitable for early generation breeding line testing. The direct small size can (202 × 214) approach required a minimum of 28.5 g bean solids which was nearly 1/4 of the sample size needed in conventional canning quality testing with a 303 × 406 can. High correlation (R²= 0.97) was found between canned bean shear texture and pasting torque values of whole bean flour (6%), w/w) at selected times/temperatures using a temperature programmed Brookfield Viscometer. The relationship between pasting torque and shear quality was promising as a basis for establishing selection criteria. The pasting test, which requires only 2 g dry bean solids, is suggested as an indirect method for screening bean breeding lines.     

SENSORY AND PHYSICOCHEMICAL CHARACTERISTICS OF PRECOOKED, MICROWAVE-REHEATABLE STEAKS

Precooked, small-portion, microwave-reheatable steaks were processed from three grades (US Choice, US Select⁺, and US Select^-) of top round beef. Marinated/tenderized samples were compared to nonmarinated/nontenderized controls from each grade. Untrained consumers (n=102) rated the sensory attributes, overall acceptability, and willingness to purchase the steaks at various settings (fast food, restaurant/cafeteria, supermarket). Marination and tenderization improved the sensory attributes, overall acceptability, and consumers' willingness to purchase the steaks, regardless of the grade from which they were prepared. Marinated/tenderized steaks from the US Select grade were more acceptable than nonmarinated/nontenderized steaks from the US Choice grade. Marinated/tenderized steaks from each grade required less force and energy to cut, contained about 3% more moisture and 0.5% less fat, and had more cooking loss than their control counterparts. However, consumers rated the marinated/tenderized products as being more tender, juicy, flavorful and more acceptable overall than controls.     

SENSORY CHARACTERISTICS OF CONTROLLED ATMOSPHERE- AND AIR-STORED ‘GALA’ APPLES1

‘Gala’ apples from two Summerland sites were harvested at two harvest dates for two growing seasons (1994, 1995) and stored for 6 months in air and controlled atmosphere (CA). At harvest maturity indices were recorded. After storage, flesh firmness, titratable acidity and soluble solids were determined and sensory attributes were evaluated by a trained sensory panel. In both years, analyses of variance showed apples picked at commercial harvest were significantly more crisp, firm, and sour and less fruity and sweet than apples harvested two weeks later. Apples stored for 6 months in CA were more crisp, firm, juicy and sour, had fewer off-flavors, and had greater overall acceptability than apples stored in air. Apples held at 1.2% O₂for 6 months were more crisp than apples stored at either 2.5% O₂ or 5% Q, while apples stored at 5.0% O were significantly less firm, juicy, and sour than apples stored using the other O₂ concentrations. Apples stored at either 1.2% and 2.5% O₂ had significantly more fruity flavor than apples stored at either 5.0% O₂ or in air.     

INTERDEPENDENCY AND UNDERLYING DIMENSIONS OF SENSORY TEXTURAL CHARACTERISTICS OF SELECTED FOODS2

Sensory texture profile data for butters, cheeses, fish gels, frankfurters, peanut butters, raw potatoes, and baked sweet potatoes were subjected to principal component analysis to study the interdependence and the underlying dimensions of the sensory textural characteristics. The results indicated that the character notes used by the panel to describe the texture profile of each product were not entirely independent but formed a pattern of interdependency in the underlying dimensional structure. The texture profile could be described by about ½ the orthogonal factors (underlying dimensions) compared to the original character notes and still explain about 72% of the original variance. It is concluded that the texture profile analysis for each of the products in this study could be simplified by reducing the character notes being evaluated.