Jeanne M. Lea

Important Sensory Properties Differentiating Premium Rice Varieties

In rice-consuming countries, specific varieties are recognized as premium, “gold standard” varieties, while others are recognized as being superior but second best, despite being identical using the current suite of tools to evaluate quality. The objectives of this study were to determine if there are distinguishable differences in sensory properties of premium and second best varieties and whether these differences are common to premium varieties. Color, an important sensory property, was determined on the raw and cooked rice using a colorimeter. As raw rice, some of the premium varieties were whiter than their second best counterparts while others were not. However, when cooked, with two exceptions, the premium varieties were of the same or greater whiteness than their counterparts. A trained sensory panel employed descriptive sensory analysis, an objective tool, to characterize and analytically measure the flavor (aromatics, taste, mouthfeel) and texture of premium and second best varieties collected from nine rice-consuming countries. Sweet taste, popcorn aroma/flavor, and water-like metallic mouthfeel showed significant differences in intensity between the premium–second best variety pairs. Slickness, roughness, and springiness were the major traits that distinguished the texture of varieties. Quality evaluation programs do not routinely measure these texture and flavor traits, but the fact that they distinguished the varieties in most pairs indicates that their measurement should be added to the suite of grain quality tests in the development of new higher-yielding, stress-tolerant varieties. The incorporation of premium quality will ensure that quality is no impediment to widespread adoption leading to enhanced productivity and food security.

Flavor of Fresh Blueberry Juice and the Comparison to Amount of Sugars, Acids, Anthocyanidins, and Physicochemical Measurements

Six cultivars of southern highbush (SHB) and rabbiteye (RE) blueberry samples were harvested on 2 different dates. Each treatment combination was pressed 2 times for repeated measures. Fresh juice was characterized for 18 flavor/taste/feeling factor attributes by a descriptive flavor panel. Each sample was measured for sugars, acids, anthocyanidins, Folin-Ciocalteu, soluble solids (BRIX), titratable acidity (TA), and antioxidant capacity (ORACFL ). Flavors were correlated with the composition and physicochemical data. Blueberry flavor correlated with 3 parameters, and negatively correlated with 2. Strawberry correlated with oxalic acid and negatively correlated with sucrose and quinic acid. Sweet aroma correlated with oxalic and citric acid, but negatively correlated with sucrose, quinic, and total acids. Sweet taste correlated with 11 parameters, including the anthocyanidins; and negatively correlated with 3 parameters. Neither bitter nor astringent correlated with any of the antioxidant parameters, but both correlated with total acids. Sour correlated with total acids and TA, while negatively correlating with pH and BRIX:TA. Throat burn correlated with total acids and TA. Principal component analysis negatively related blueberry, sweet aroma, and sweet to sour, bitter, astringent, tongue tingle, and tongue numbness. The information in this component was related to pH, TA, and BRIX:TA ratio. Another principal component related the nonblueberry fruit flavors to BRIX. This PC, also divided the SHB berries from the RE. This work shows that the impact of juice composition on flavor is very complicated and that estimating flavor with physicochemical parameters is complicated by the composition of the juice.

Correlation of Sensory, Cooking, Physical, and Chemical Properties of Whole Grain Rice with Diverse Bran Color

ABSTRACT Whole grain rice is nutrient dense because of the intact bran layer. The literature indicates that there is genetic variability for compounds in the bran layer of whole grain rice with some compounds in high concentrations in varieties with pigmented bran. The purpose of this study was to compare factors that impact sensory characteristics between different classes of rice bran color. Ten varieties, two from each of five bran colors (white, light brown, brown, red, and purple), were evaluated for descriptive flavor and texture, physical characteristics, gelatinization temperature, apparent amylose content, and polyphenols. Rice that has red or purple pigmented bran has higher contents of phenols and flavonoids, and these varieties were strongly correlated with some flavor attributes. The bran/hay/straw attribute correlated with bran weight and bran thickness, and sweet taste negatively correlated with amylose content. The texture attribute of hardness was significantly different among bran colors...

Impact of Presoaking on Flavor of Cooked Rice

ABSTRACT Soaking rice in water for 30 min or longer before cooking is traditionally practiced in Japan, Korea, and other Asian countries. When soaked, the rice grains hydrate, develop cracks, and water is absorbed. Soaking facilitates uniform cooking and shortens cooking time. The cooked kernel is usually less firm. The present study was undertaken to determine the effects of presoaking on the flavor of cooked rice and whether flavor differences are associated with textural changes that could influence retention of aroma compounds. Eleven samples of short, medium, and long grain milled rice representing scented and nonscented rice and a wide range of amylose contents were presented to a descriptive sensory panel. For the set of all rice samples, undesirable sewer/animal flavor significantly increased and sweet taste significantly decreased with presoaking for 30 min. For individual rice samples, significantly higher sewer/animal intensity was observed with presoaking for the 2 Basmati rice samples and one...

Relating raw rice colour and composition to cooked rice colour

BACKGROUND The whiter the rice, the more it is preferred by consumers and the more value it has in the market place. The first objective of this study was to determine the interrelationships of raw colour, cooked colour, amylose content and protein content in rice. The second objective was to assess whether or not the colour of cooked rice can be predicted from raw rice colour in conjunction with amylose and protein contents. RESULTS Protein and amylose contents were not significantly correlated with the colour measurements for raw rice. Protein and amylose showed moderate, significant associations with L* and a* and a*, b* and C* respectively for cooked rice. Only the colour variable a* of cooked rice could be predicted using protein, amylose and raw rice colour with high enough precision to be useful, and this was only for modelling using samples cooked in the same manner (rice cooker). Cooking method (rice cooker versus excess water) affected the colour of cooked rice. CONCLUSION Being able to predict a* in cooked rice is likely of limited value. Only the model that used samples where postharvest handling conditions were controlled (US-grown rice) was able to predict C*, a more useful measure, and then with only moderate ability. L*, a measure of brightness/whiteness, was not predicted well by any of the models.

Influence of Cooking Formulation on Flavor and Hydrophilic Oxygen Radical Absorption Capacity Values of Whole Grain Colored Rice

ABSTRACT Whole grain rice is rich in healthful polyphenolic compounds that can impart undesirable flavors. Rice is typically prepared with water and sometimes salt, oil, or both, which can influence flavor. This research examines the influences of cooking whole grain rice with salt, oil, or both on flavor and antioxidant capacity. Nine commercial rice samples (three brown, three red, and three black or purple) were cooked with water only, added salt (0.5%), oil (1.575% v/w), or salt with oil (same concentrations). Flavor was measured with descriptive flavor analysis, and antioxidant capacity was measured by the hydrophilic oxygen radical absorption capacity (H-ORAC) method. The addition of salt and salt with oil significantly reduced bitter, waterlike/metallic, and astringent flavors, whereas corn/popcorn/buttery flavor was increased. Cooking formulation significantly affected more flavor attributes in black/purple and brown bran samples than in the red bran samples. Salt, oil, or both can be added to ric...

Effects of beer-battering on the frying properties of rice and wheat batters and their coated foods

BACKGROUND Beer in batter formulation or beer-battering has been popular in fried food recipes, but the topic is rarely reported in scientific journals or the claims substantiated with reliable studies. In this research, we prepared and characterized rice and wheat batters with and without using beer to replace water in the formulation. We studied and provided data on the effect of beer on the frying properties of batter and its coated foods. RESULTS With beer in the formulation, oil uptake of fried batters generally increased by up to 18%. Instrumental textural analyses indicate that beer-battering treatment generally decreased the hardness, increased the fracturability and improved the crispness of the fried batters. Sensory evaluations show similar trends, though to a lesser extent, that fish and onion rings coated with batters were softer but crispier with beer than without. CONCLUSION In general, beer-battering caused an increase in the oil uptake of the batter during frying. It also made the texture of fried batters slightly softer and crispier. The effects are more pronounced for rice batters than wheat batters.

Effect of Par Frying on Composition and Texture of Breaded and Battered Catfish

Catfish is often consumed as a breaded and battered fried product; however, there is increasing interest in breaded and battered baked products as a healthier alternative. Par frying can improve the texture properties of breaded and battered baked products, but there are concerns about the increase in lipid uptake from par frying. The objective of this study was to examine the effect of different batters (rice, corn, and wheat) and the effect of par frying on the composition and texture properties of baked catfish. Catfish fillets were cut strips and then coated with batters, which had similar viscosities. Half of the strips were par fried in 177 °C vegetable oil for 1 min and the other half were not par fried. Samples were baked at 177 °C for 25 min. Analysis included % batter adhesion, cooking loss, protein, lipid, ash, and moisture, plus hardness and fracture quality measured using a texture analyzer. A trained sensory panel evaluated both breading and flesh texture attributes. Results found the lipid content of par fried treatments were significantly higher for both corn and wheat batters than for non-par fried treatments. Sensory analysis indicated that the texture of the coatings in the par fried treatments were significantly greater for hardness attributes. Fillet flakiness was significantly greater in the par fried treatments and corn-based batters had moister fillet strips compared to the wheat flour batters. Texture analyzer hardness values were higher for the par fried treatments.

Comparison of sensory and instrumental methods for the analysis of texture of cooked individually quick frozen and fresh-frozen catfish fillets

Abstract Catfish fillet texture is important to consumers, especially if the texture is not what the consumer expects. Therefore, it is important to be able to assure that texture quality is consistent. Texture is a humanly perceived sensory trait and can be costly to processors when texture quality is substandard. Instrumental methods of monitoring texture are much less costly over time than maintaining a sensory quality panel. The purpose of this research was to develop methods for monitoring texture quality using reliable instrumental methods. A descriptive sensory texture panel evaluated fresh‐frozen and individually quick frozen (IQF) catfish fillets and was compared to the instrumental analysis of the same cooked fish, using texture profile analysis (TPA). The TPA evaluation was more successful for identifying differences between IQF and fresh‐frozen catfish, with the most significance (p < 0.02) seen for the attributes springiness, resilience, chewiness‐1, hardness‐1, and residual parameters of springiness, chewiness‐1, chewiness‐1b, and hardness‐1b. For sensory evaluation, only moisture release and moisture retention were this significant. Overall, IQF fillets were more moist and cohesive, with fresh‐frozen fillets greater in all other parameters. Predictive equations were developed for sensory texture attributes from various TPA attributes calculated from the compression–force curves generated from two compressions of a ball probe. In the fresh‐frozen catfish, sensory attributes firmness, flaky, moisture retention, and residual cohesiveness of mass had correlation coefficients (R) of 0.50 or greater. For the IQF catfish, all sensory attributes had an R of less than 0.4. The firmness sensory attribute had TPA predictor variables in both fresh‐frozen and IQF that consisted mainly of hardness, chewiness, or thickness‐related attributes. Based on results, instrumental texture of catfish should be measured before further processing, such as IQF.

Chemical and nutritional properties of channel and hybrid catfish byproducts

Abstract The objective of this study was to chemically characterize both channel and hybrid catfish parts including heads, frames, viscera, skin, and fillet trimming mince. Triplicate samples of channel and hybrid catfish byproduct parts were obtained from a large commercial catfish processor and analyzed for percent moisture, lipid, protein, ash, and amino acid and fatty acid profiles were determined. The content of the off‐flavor compounds, 2‐methylisoborneol (MIB) and geosmin were also determined. The lipid content of samples were 13.6% and 10.0% for channel and hybrid skins, 17.7% and 21.4% for channel and hybrid viscera, 20.0% and 19.1% for channel and hybrid frames, and 9.7% and 9.3% for channel and hybrid heads. The protein content of samples ranged from a high of 22.8% for channel catfish skins, to a low of 13.4% for channel frames. Low levels of geosmin, <1 ppb, were detected in the byproduct samples, while no MIB was detected. Palmitic, oleic, and linoleic acid comprised approximately 80% of the fatty acids in the byproduct tissues. The amino acid profiles indicated that the catfish mince had high levels of lysine and methionine and other essential amino acids. Results from this study will be used in the development of new value‐added products from catfish byproducts.