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.     

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.     

POSTHARVEST SENSORY AND PHYSIOCHEMICAL ATTRIBUTES OF PROCESSING AND NONPROCESSING TOMATO CULTIVARS

Fruits of processing and nonprocessing tomato cultivars harvested at the “breaker” stage of maturity were evaluated for changes in physical, chemical and sensory quality characteristics during storage at 20C and 30C after 7, 14 and 21 days. Percentage marketable fruits after 21 days at 20C and 30C were 61.9% and 56.6% for processing cultivars and 65.9% and 50.9% for nonprocessing cultivars. Fruits of the processing cultivars ripened earlier, remained firmer and were less prone to physical injuries than fruits of nonprocessing cultivars. Nonprocessing fruits had a higher mean fruit weight of 17.0 g, fruit diameter of 1.10 mm and locule number of 13 compared with fruits of the processing cultivars. Nonprocessing fruit cultivars had higher sugar/acid ratios and vitamin C contents as well as lower pH and total titratable acidity than processing fruit cultivars. Accordingly, nonprocessing cultivars on the whole, but specifically Walters, Floradel, Carnival, Calypso, Star Pak, Floradade and Early Set were most suitable as fresh-market fruits. Excellent processing quality attributes were obtained for Donore, Peto 94C, Rio Grande and Advantage. Among processing cultivars Caraibe, Cascade, Dorado and Neema 1401 gave good dual purpose fruits.     

EFFECT OF PRESSING ON MOISTURE LOSS AND SENSORY PROPERTIES OF BEEF

Paired halves of top round (Semimembranosus and Adductor muscles) sub-primals were removed from each of ten, USDA Choice, approximately 272 kg steers, freezer wrapped, frozen, and stored at -24° C for approximately 1 month. Following freeze-tempering, each primal was divided longitudinally with one half being pressed at 344 Newtons/cm² to a specified shape in a Bettcher Model 70 Press, while the other half served as nonpressed control. Moisture loss and sensory properties were determined for 2.54 cm thick steaks. No significant differences were found in juiciness, flavor or Kramer shear values between pressed and non-pressed top round steaks, however, sensory tenderness scores were lower (P < 0.05) for steaks that were pressed than for those that were not pressed. Holding steaks at 2° C for 0, 1, 2, or 3 days did not significantly alter Kramer shear or sensory panel evaluations. Cooking loss, drip loss and total loss were not affected by pressing. Drip loss was lower (P < 0.05) and cooking loss was higher (P < 0.05) for steaks held one day at 2° C than for steaks held 2 or 3 days at 2° C. When drip loss and cooking loss were combined (total loss) there was no difference among the four storage times. Drip loss following portion cutting could result in a problem in fresh merchandising of freeze-tempered cuts.     

VOLATILES OF PALM WINE USING SOLVENT EXTRACTS

Solvent extracts of palm wine early in fermentation (12% sugar, pH 7), during active or mid fermentation (6% sugar, pH 3.6) and towards the end of fermentation (2% sugar, pH 3.6) were obtained using dichloromethane and diethyl ether. The extracts were analyzed by gas chromatography and gas chromatography-mass spectrometry. Altogether, 73 compounds were identified, 45 of which had not been previously reported in palm wine. The qualitative and quantitative differences between the chromatograms of extracts of palm wine early in fermentation and at mid fermentation suggest that the flavor volatiles of palm wine derive mainly from fermentation. The occurrence of acetic acid early in the fermentation suggests that it is the first volatile acid and in fact one of the first volatiles produced in palm wine fermentation, contrary to previous assumptions. The lactic fermentation, reported to initiate palm wine fermentation, is thought to be responsible for this. That fermentation must therefore be prevented in palm exudates destined to be used for any product where acetic acid is undesirable.     

EFFECT OF FLOW RATES ON THE STORAGE PROPERTIES OF PALM OIL-BASED MARGARINE

The effect of flow rates on the production of palm oil-based margarine was studied. The flow rates studied were 15, 30, and 45 kg/h, with other parameters such as emulsion and tube cooler temperature, speed of the tube cooler, intermediate crystallizer and pin worker unit kept constant. The margarines were significantly different in their consistencies, solid fat content (SFC) and polymorphic behavior during processing and storage at 28C. The SFCs in the tube cooler and the pin worker units corresponded with the flow rates, while crystallization affected the temperatures of the product during processing. Margarine production at a flow rate of 30 kg/h afforded the highest margarine consistency during storage, while 45 kg/h gave the lowest. However, the highest and lowest SFC was from samples of 30 kg/h and 15 kg/h, respectively. The transformation of β to β crystal had occurred at the second, third and fourth week of storage in samples of 45, 15 and 30 kg/h, respectively.     

冻藏时间对速冻水饺品质影响的试验研究

主要考查冷冻保藏时间对于速冻水饺的理化性质、微生物指标及感官性状的影响。结果表明,随保藏时间延长,饺皮的水分含量呈线性规律下降,从最初的（37．25&#177;0．44）％降至试验末期的（32．5&#177;0．92）％。而对于样品的酸价,随保藏时间延长,酸价升高,从初始的（2．01&#177;0．01）mg KOH／g升至试验末期的（2．38&#177;0．02）mgKOH／g。菌落总数及嗜冷菌菌落总数结果相似,都随保藏时间延长而增加,菌落总数从（1．27&#177;0．09）&#215;10^5 cfu／g升至（3．26&#177;0．08）&#215;10^5 cfu／g,而嗜冷菌菌落总数从（2．44&#177;0．06）&#215;10^5 cfu／g升至（3．73&#177;0．15）&#215;10^5 cfu／g。结合对水饺饺皮和饺馅的感官评价表明,速冻水饺的食用品质随保藏时间呈下降趋势,相对来讲,保藏时间越短,样品的食用品质越好。