EFFECT OF YAM VARIETY ON THE PASTING PROPERTIES AND SENSORY ATTRIBUTES OF TRADITIONAL DRY-YAM AND ITS PRODUCTS

ABSTRACT

Six varieties of yam were processed into traditional dry‐yam slices. The pasting properties and sensory attributes of dry‐yam samples, flour and paste from the flour were investigated. Significant differences (P ≤ 0.05) were observed in the pasting properties of flour from different yam varieties. “Ijedo,” the commonly used variety, had the highest peak, trough and final viscosities. There was no significant difference in the viscosities of “Efuru” (206.04 rapid viscosity analyzer), “Ise‐Osi” (242.75 rapid viscosity unit [RVU]) and “Abuja” (241.25 RVU) varieties. Samples of dry yam made from “Efuru,”“Ise‐Osi” and “Abuja” yams were not significantly different (P > 0.05) from “Ijedo” in terms of instrumental color measurement, as their degree of brownness (100 − L*) were 21.53, 19.21, 20.87 and 22.42, respectively. There was no significant difference (P > 0.05) in color, taste and moldability of the paste made from “Efuru,”“Ise‐Osi,”“Ijedo” and “Abuja” yams. There was no significant difference (P > 0.05) between the hardness of dry yams made from “Ise‐Osi,”“Ijedo” and “Abuja.” There were positive correlations between the yam paste moldability, peak, trough and final viscosities for the different yam varieties. “Ise‐Osi,”“Efuru” and “Abuja” varieties were found to be suitable for dry‐yam processing in terms of sensory property and pasting of dry‐yam slices and their products, which were not significantly different from those of “Ijedo” variety – the commonly used yam.

PRACTICAL APPLICATIONS

The study revealed that dry‐yam processors and potential dry‐yam processors in Nigeria can use other white yam varieties, such as “Abuja,”“Ise‐Osi” and “Efuru,” apart from “Ijedo” variety – the commonly used yam variety. These yam varieties were also acceptable in terms of the sensory and pasting properties of dry‐yam slices and their products. Thus, the general knowledge that white yams are good for dry‐yam processing has been scientifically verified.

     

EFFECT OF NATIVE AND LYOPHILIZED KEFIR GRAINS ON SENSORY AND PHYSICAL ATTRIBUTES OF WHEAT BREAD

Native and lyophilized kefir grains were added directly to bread dough or as a starter in sourdough. Because of inadequate leavening activity of kefir, yeast‐leavened breads were prepared. Kefir addition influenced the quality attributes and the shelf life of wheat bread. The pH of bread containing kefir decreased as compared to that in the control bread. The acidity of bread with kefir increased as compared to that in the control bread. An addition of kefir grains, regardless of the form, lowered the bread volume and increased the mold‐free shelf life from 4 (control) to 5–7 days. The addition of kefir grains in bread dough contributed to a milder taste, a more delicate yogurt‐like or dairy aroma. The breads made with sourdoughs containing native or lyophilized kefir grains scored higher for crumb quality number than breads made by directly adding kefir grains.     

THE EFFECT OF RACTOPAMINE AND INTRAMUSCULAR FAT CONTENT ON SENSORY ATTRIBUTES OF PORK FROM PIGS OF SIMILAR GENETICS

The objective of this research was to determine how marbling influences sensory properties of pork. Fresh boneless pork loins were collected from 229 barrows of the same genetic line over a 2-day period from a commercial slaughter facility. Live phase treatments included a control diet and the control diet supplemented with ractopamine (RAC) at 5 ppm for the final 28 days. Multiple 2.54-cm chops were cut for determination of proximate composition, cook loss, Warner–Bratzler shear force and sensory analysis. RAC minimally affected pH and objective color, but had no effect on other pork quality measurements. Additionally, the relationship between extractable lipid and sensory properties or shear force was weak. These results suggest that the level of intramuscular fat has little to do with the eating quality in this population of pigs.

PRACTICAL APPLICATIONS

The interest in highly marbled pork is based upon historical research that indicated increased marbling was beneficial to shear force values and sensory properties. Our research demonstrates that within a single genetic line, marbling does not dramatically affect sensory properties. Research of this type will help guide both consumers and the pork industry in a positive direction to determine factors that affect palatability and ultimately consumer satisfaction.     

壳聚糖对糟辣椒发酵作用及保藏特性影响

尝试在糟辣椒加工保藏中添加壳聚糖,研究其对糟辣椒品质及保藏性影响.通过对糟辣椒总酸、VC、亚硝酸盐含量和菌落总数的检测,以及感官品质评定,结果发现:壳聚糖对糟辣椒前期乳酸发酵有一定抑制作用,而发酵结束后其总酸含量与对照差异不大;保藏期间壳聚糖组VC损失率、亚硝酸盐积累均较苯甲酸钠组和对照组低;壳聚糖能明显提高产品耐藏性,并对糟辣椒褐变有一定抑制作用,对其感官品质无不良影响.综合指标评价得出:在糟辣椒发酵中添加壳聚糖能提高产品品质及保藏特性,试验中0.3%壳聚糖添加量效果最佳.     

EFFECT OF ATMOSPHERE ON BROCCOLI SENSORY ATTRIBUTES IN COMMERCIAL MAP AND MICROPERFORATED PACKAGES1

Broccoli was packaged using 2 microperforated (cross-micro, SM60®) and 3 modified atmosphere packages (MAP) (polyethylene MAP, broccoli MAP, lettuce MAP). Packaged broccoli was stored 9 days at 2C and an additional 1, 3, 4 and 6 days at 13C, for a total storage 10, 12, 13 and 15 days, respectively. Concentrations of CO₂ and O₂ were determined after 12 days. Sensory analyses were conducted after 10, 12, 13, and 15 days. Broccoli quality was evaluated for ten sensory attributes by eight trained judges. Analysis of variance and principal component analysis were used to determine the effect of packaging and storage time. Broccoli packaged in lettuce MAP was most anaerobic (3.9% CO₂, 1.2% O₂) and developed sauerkraut-like odors/flavors after 10 days of storage. The microperforated wraps did not alter the gas composition of the packages (16.3% O₂, 0.2% CO₂) and broccoli became yellow and limp after 15 days. In contrast, broccoli packaged in the polyethylene and broccoli MAP packages modified the CO₂ and O₂ concentrations and maintained the broccoli quality for the duration of the experiment (15 days).     

THE ROLE OF MICROBIAL GUMS IN THE COLOR AND CONSISTENCY OF PALM WINE

Viscosity and soluble color changes in palm wine during fermentation were found to show an early increase followed by a gradual decline. Addition of absolute alcohol to palm wine precipitated gums that were absent in the palm sap, indicating production during fermentation. Precipitation of the gum was accompanied by loss in coloration and a significant reduction in viscosity. These properties were regained on reintroduction of the gum showing that the gums were responsible for the properties. Yeasts and bacteria isolated from palm wine were employed in pure culture fermentations of sterile palm sap to determine the origin of the gums. The results showed that the gums were produced mainly by leuconostocs, while two other bacteria not fully identified and a homofermenting Lactobacillus spp. also produced some. Analysis showed the Lactobateriaceae gums to be all glucans, while the gums of the other bacteria were fructans. Palm wine was found to contain both types of gum (80% glucans, 20% fructans), showing that many bacteria produce gums in palm wine concomitantly.     

THE INFLUENCE OF SALT AND HYDROLYZED VEGETABLE PROTEIN ON THE SENSORY ATTRIBUTES OF GROUND COW BEEF PATTIES

Ground cow beef was formulated to contain NaCl (0%, 1% or 2%) and hydrolyzed vegetable protein (0%, 0.25%, 0.50% or 0.75%) and was made into patties. Cow beef and steer beef patties without salt or HVP were utilized as controls. Patties were evaluated for fat and moisture content and sensory attributes. Meat source had no significant effect on fat and moisture content or on sensory attributes. The addition of NaCl resulted in patties that were more juicy, more tender and more desirable in flavor and texture than the control patties. Sensory ratings increased as the level of added salt increased. Patties containing 0.25% hydrolyzed vegetable protein were more tender, more juicy and received higher texture and flavor desirability ratings than patties containing 0%, 0.50% or 0.75% hydrolyzed vegetable protein.     

SENSORY AND MECHANICAL ATTRIBUTES OF GEL TEXTURE

Eighteen experienced judges evaluated the texture of gels varying in gelatin concentration (22-45 g/L) in terms of firmness by oral and manual shear and compression, cohesiveness, and extent of breakdown in the mouth. Manual compression and biting with the front teeth discriminated well across gel concentrations. All sensory measures except extent of breakdown increased with gelatin concentration. Instron (IUTM) measurements showed that increasing gelatin concentration resulted in an increase in maximum force and force/deformation, but had little effect on deformation at yield and rupture or in elasticity and cohesiveness. Results from mechanical measurements varied with the type of force applied (compression, shear or puncture), the loading rate (50 or 200 mm/min), and the extent of deformation attained (40–90%). The highest discrimination across gel concentrations was achieved with shear force at a rate of 200 mm/min and at greater deformations. Sensory responses correlated most highly with the following IUTM measurements: (1) Compression forces at yield and at deformations of 70 and 85% at the higher crosshead speed; (2) Compression forces below the yield point at the lower crosshead speed; and (3) Shear forces measured at maximum deformation (90%) at 200 mm/min.     

EFFECT OF GLUCOSE SYRUP SOLID, SUCROSE, HYDROGENATED PALM OIL AND SOY-LECITHIN ON SENSORY ACCEPTABILITY OF DURIAN LEATHER

A two-stage optimization of ingredients in durian leather formulations was conducted using Response Surface Methodology (RSM). In stage 1, the independent variables were glucose syrup solids (GSS) and sucrose, and in stage 2, the variables were hydrogenated palm oil (HPO) and soy-lecithin (SL). Based on the responses to sensory acceptability attributes including taste, aroma, texture, appearance and overall acceptability, the most acceptable formulation was a combination of 10% GSS, 5% sucrose, 2.67% HPO and 0.452% SL. Chemical analysis also showed that during processing nutrient composition was relatively unchanged.     

THE EFFECT OF GLASS SHAPE ON THE CONCENTRATION OF POLYPHENOLIC COMPOUNDS AND PERCEPTION OF MERLOT WINE

Accepted opinion among wine connoisseurs is that size and shape of a glass used to serve wine can affect color and flavor of wine. Glass manufacturers and the wine industry could benefit from a greater understanding of the relationship between glass shape and wine appreciation. However, extensive oxidation may reduce antioxidative properties of polyphenolics that are highly prized in red wines. The objective of this study was to determine the effect of geometries of three glass types (Flute, Bordeaux, Martini) on sensory perception and concentration of polyphenolic compounds in Merlot wine as a function of time. Sensory evaluation was conducted with a 12‐member panel. Triangle tests were chosen to determine whether any difference in flavor could be perceived between samples stored for 0, 15 and 30 min in the three glass types. Phenolic compounds, gallic acid, caffeic acid, catechin and vanillin, were quantified using HPLC. Results indicated that the panelists could not perceive differences between wine served in different glasses even if it was exposed to air for 30 min at room temperature. Although concentration of phenolics, especially gallic acid, was affected by the exposure to air, changes were not profound enough to affect the sensory qualities of Merlot wine as judged by occasional wine drinkers.     

Nisin对冷却猪肉冷藏保鲜效果的影响

研究Nisin对冷却猪肉保鲜效果的影响.研究中对比Nisin与山梨酸钾两种保鲜剂对冷却猪肉冷藏过程中6项鲜度指标(细菌总数、挥发性盐基氮、pH值、球蛋白、硫化氢以及感官指标)的变化情况.结果表明:Nisin在0.03 g/L～0.06 g/L浓度范围内可延长冷却猪肉货架期,其中以0.05 g/L Nisin保鲜液浸泡猪肉120 s保鲜效果最佳,货架期可延长6d,且与山梨酸钾保鲜剂(0.05 g/L)保鲜效果无明显差异.     

SENSORY PROFILE OF AIREN GRAPES AND THEIR MUSTS FOR THE PREDICTION OF THE WINE CHARACTERISTICS

Eight sensory attributes, freely chosen by the panelists, permitted the differentiation of Airen grapes belonging to five Spanish viticultural subzones (Moral, Sierra, Sudeste, Vega and Abertura) by means of their spiderweb diagrams. Another nine attributes distinguished the corresponding musts. Application of PCA to the sensory scores revealed that five attributes explained 81.9% of the variance existing among grapes grown in the different subzones. A similar result was obtained for the musts. Grapes from two of the five subzones, Moral and Sierra, yielded the highest scores with regard to overall impression. Consequently, from the results obtained it is advisable to harvest Airen grapes when the sugar is close to 200 g/L, and total acidity is less than 5 g/L (tartaric acid), while they still present green hues and a berry diameter between 1.3–1.5 cm. In this way the fruity character and absence of astringency was ensured in the obtained musts, both attributes being desirable in order to achieve good quality wines.     

PHYSICOCHEMICAL CHARACTERISTICS AND SENSORY ATTRIBUTES OF WHEAT-BASED "PAPADS" INCORPORATED WITH GREEN LEAFY VEGETABLES

Papads are cereal or legume‐based preserved products which are consumed after deep fat frying. They were chosen for value addition with two types of green leafy vegetables (GLV). Wheat‐based papads were prepared using refined wheat flour, cumin seeds, salt and GLV, that is, shepu (Peucedanum graveolens) and kilkeerae (Amaranthus tricolor) at different levels in fresh (15 and 20%) and dehydrated forms (5 and 10%). Greens were analyzed for their proximate principles, selected minerals and vitamins. In the fried papads, fat uptake and expansion volume were determined. The fried papads were subjected to sensory analysis by a panel of 100 members. Expansion volume of papads with fresh greens and 5% dehydrated greens were satisfactory, but differences existed between the greens. Fat uptake of kilkeerae papads was similar to that of control papads but shepu‐incorporated papad showed slightly lower absorption. Papads with 15–20% fresh greens and 5% dehydrated greens scored above 6 on a scale of 10 indicating acceptability of papads incorporated with greens. Mineral, vitamin and fiber content of greens‐incorporated papads increased remarkably. Acceptability of papads in terms of physicochemical characteristics, sensory attributes and nutritional quality suggests the suitability of papads incorporated with greens.