QUALITY AND STABILITY OF BLUEBERRY JUICE BLENDED WITH APPLE,GRAPE AND CRANBERRY JUICE1

Sensory quality and storage stability of blueberry juice blends were investigated with the goal of maintaining dominant blueberry flavor, aroma and color. Apple juice, Concord and Venus grape juices and cranberry juice cocktail were blended at 75, 50 and 25% with blueberry juice. As the percent of blueberry juice decreased, the intensity of blueberry‐related sensory attributes decreased. The 25% Concord and Venus blends were the only blends that resulted in blueberry flavor similar to the reference. Apple and cranberry juice cocktail blended with blueberry juice produced several blends with good flavor and aroma, but they were not readily characterized as blueberry juice. All blends at the 25% level produced blueberry color equal to or greater than the reference. The juice samples were evaluated initially and after three months of storage at 37C. After storage, all blends had decreased red color.     

A PROCEDURE FOR QUANTITATIVE ESTIMATION OF MALIC AND TARTARIC ACIDS OF GRAPE JUICE

The ion-exchange behaviors of succinic, malic and tartaric acids on Amberlite resins are evaluated. Retention and detector response data on silyl derivatives of several organic acids are presented. A procedure for the purification of grape juice by use of ion-exchange resins prior to gas chromatography is described. The malic and tartaric acid contents (g/100 ml juice) respectively, of commercially acceptable grapes were found to be: Thompson Seedless 0.25, 0.90; Cardinal 0.31, 0.91; Beauty Seedless 0.19, 0.62; Perlette 0.26, 0.97; Exotic 0.27, 0.36; and Robin 0.41, 0.37.     

FUNCTIONAL PROPERTIES OF SORGHUM FLOUR AS AN EXTENDER IN GROUND BEEF PATTIES 1

Patties were formulated with 20% fat ground beef and sorghum flour (SF) at 2, 4, and 6% levels (10, 20, and 30% as rehydrated 1:4 with water). Beef patties containing SF had higher pH, greater yield, less total cooking loss, less shrinkage in diameter, and less increase in thickness than those without SF. Water activity of cooked patties was not affected by addition of SF. Fat and water retentions of beef patties increased as the level of SF increased. Hunterlab a values (redness) for raw patties decreased as the level of SF increased, but a values for cooked patties were not influenced by level of SF. Shear force and compression of cooked patties decreased as the level of SF increased. Meat aroma and flavor decreased, but sorghum aroma and flavor of cooked patties increased as the level of SF increased. Tenderness of cooked patties increased as the level of SF increased, but juiciness of cooked patties was not affected.     

PHYSICOCHEMICAL AND SENSORY PROPERTIES OF MUSCADINE GRAPE JUICE AND CONCENTRATES

Juices from bronze and red muscadines were concentrated by low-temperature vacuum evaporation. Half of each of the lots was treated with a mixture of pectinolytic and cellulolytic enzymes and the other half untreated. Red juice was higher in soluble solids and Brix-to-acid (BTA) than bronze, but pH, acid, and viscosity were similar. When concentrated to 68° Brix, the BTA was the same regardless of juice type. Enzyme treated samples were not different from their nontreated counterparts, except for slightly higher pH of treated red juice. Hue angle for bronze concentrate shifted from about 100 to 78 while chroma increased. Hue for the red juice shifted from about 40 to 95, while chroma remained constant. Fructose and glucose were the major sugars with sucrose averaging less than 1%. Panelists rated the bronze reconstituted juices lower in color intensity, aroma intensity, sweetness, acidity, and flavor than the single-strength juice. However, the red reconstituted juices were rated higher in color intensity than their single-strength counterparts. Panelists rated reconstituted juices higher when reconstituted with essence recovered plus water than with water only.     

胶原蛋白复合果汁饮料的生产工艺及稳定性研究

采用单因素试验和正交试验,对胶原蛋白复合果汁饮料配方、生产工艺及其稳定性进行研究.结果表明:饮料的原料优化配比(质量比)为:有机酸(柠檬酸与苹果酸的质量比为2:1)O.4%,蔗糖6%,复合果汁25%,胶原蛋白3%;复合稳定荆的最佳组合为:黄原胶0.04%,耐酸CMC0.10%,海藻酸钠0.15%,阿拉伯胶0.10%;均质压力为25MPa,杀茵温度及时问为80℃.时间为20min.     

RETENTION OF FRESH ORANGE JUICE FLAVOR AND AROMA IN AN AQUEOUS DISTILLATE FROM VALENCIA ORANGE JUICE1

Freshly squeezed Valencia orange juice, distilled at low temperature and reduced pressure, yielded an aqueous distillate with the necessary balance of volatile flavor and aroma constituents to retain the fresh juice characteristics. Flavor comparisons by an experienced sensory panel determined that orange juice reconstituted by combining the aqueous distillate with the residual juice solids had significantly more fresh juice character than reconstituted commercial frozen concentrated orange juice; commercial not pasteurized single strength orange juice (SSOJ); pasteurized SSOJ, not from concentrate; canned SSOJ, from concentrate; or aseptically packed SSOJ, from concentrate. The panel also found no significant difference in fresh juice characteristics between freshly squeezed orange juice and distillate and residual solids recombined from the same juice sample. Fifty four volatile constituents were identified from the aqueous distillate of freshly squeezed orange juice.     

AN ENZYMATIC PROCESS FOR A PROTEIN-CONTAINING BEVERAGE BASED ON SOYBEAN PROTEIN AND LEMON JUICE

SUMMARY —An acidic enzymatic process for a bland soybean protein hydrolysate is described. Cooked suspensions (5.0%) of isolated soybean protein are mixed with small amounts of an acid-protease preparation from Trametes sanguinea, adjusted to pH 3.3–3.5 with concentrated lemon juice and incubated at 50°C for 8–10 hr. After stopping the proteolysis by heat treatment, the clear supernatant is separated from any insoluble residue by centrifugation. A solubilized nitrogen recovery of 88–90% is obtained. All nitrogenous substances in the hydrolysate are 5% trichloroacetic acid-soluble, and the dehydrated hydrolysate easily reconstitutes to a clear solution with cold water. After being diluted about twice and sweetened with sugar, the hydrolysate constitutes a clear, slightly yellowish lemonade-like flavored beverage. The data on chemical analysis, gel-filtration and rheological behavior of the hydrolysate are also described and discussed.     

DETERMINATION OF ORTHO-NASAL AROMA THRESHOLD FOR MULTICOLORED ASIAN LADY BEETLE IN A CONCORD GRAPE JUICE

ABSTRACT

Sensory evaluation was used to determine the aroma threshold of Harmonia axyridis (multicolored Asian lady beetle [MALB]) in Concord grape juice. Prior to Concord grape juice preparation, MALB was added to the Concord grapes at concentrations of 0 and 8.4 MALB/kg fresh grapes. To determine the odor threshold, the three alternative forced‐choice method of sample presentation was used, with an ascending concentration series of 0.5, 1.5 and 4.5 MALB/kg fresh grapes. The panel aroma threshold concentration, calculated using the best estimate threshold over two panel sessions, was 1.8 MALB/kg fresh grapes. Individual detection thresholds ranged from 0.29 to 7.79 MALB/kg fresh grapes, with 75% of the panelists having a detection threshold at or below 0.87 MALB/kg fresh grapes. These results indicate the influence of low numbers of MALB on Concord grape juice aroma, and suggest the importance of quality control programs, including the implementation of established tolerance limits, to monitor grape quality.

PRACTICAL APPLICATIONS

Harmonia axyridis, the multicolored Asian Ladybeetle (MALB), was originally introduced as a method of biocontrol. However, its presence is now becoming problematic with respect to crop quality. In order to minimize economic losses to the Concord grape industry, determination of the number of MALB required to produce a detectable change in Concord grape juice is critical for juice producers in the establishment of their quality control programs. Therefore, the objective of this study was to determine the aroma threshold level of MALB in Concord grape juice. The panel aroma threshold concentration, calculated using the best estimate threshold was 1.8 MALB/kg fresh grapes, with 75% of the panelists having a detection threshold at or below 0.87 MALB/kg fresh grapes. These results indicate the influence of low numbers of MALB on Concord grape juice aroma, and suggest the importance of quality control programs, including the implementation of established tolerance limits, to monitor grape quality.

     

WILD RICE AS AN ANTIOXIDANT FOR FRESH-FROZEN AND PRECOOKED BEEF PATTIES

Antioxidant effects, as measured by thiobarbituric acid reactive substances (TBARS), of ground cooked Minnesota wild rice (WR) added at 0, 15 and 25% (weight-weight) to fresh-frozen and precooked extra lean ground beef patties were investigated. WR generally resulted in more desirable sensory panel ratings and lower TBARS values for the fresh-frozen product at 8 weeks frozen storage but not at 0 week or 16 weeks. WR, especially at the 25% level, generally resulted in more desirable sensory panel ratings and lower TBARS in the precooked product at 4 and 8 weeks frozen storage. Ground WR can be an effective antioxidant in fresh-frozen and precooked ground beef patties stored at ?23C.     

EFFECTS OF PROCESSING TIME AND TEMPERATURE ON THE QUALITY COMPONENTS OF CAMPBELL GRAPE JUICE

Campbell grape juice was processed at different temperatures (60, 70, 80 and 90C) and different times (30, 45 and 60 min), and evaluated for quality components and sensorial properties. The grapes were crushed, added with enzyme, heated, and pressed; then the juice was cold stabilized, filtered and pasteurized. The samples showed an increase in pH and a decrease in titratable acidity. Sugar/acid ratio and total soluble solids increased until 80C then decreased when 90C was reached. A slight increase in L* and b* values and a decrease in a* color values were also shown. Significant differences were mostly observed between processing temperatures than between processing times. Increasing processing temperature enhances the total phenolics, total anthocyanin and total flavonoid contents, and % radical scavenging activity of the juice until 80C but declined when the temperature reached 90C. Sensory evaluation showed that the preferred time–temperature combination for processing Campbell juice is between 70 and 80C for 30–45 min.

PRACTICAL APPLICATIONS

Campbell Early ( V. labrusca B.) is one of the major table grapes in Korea and overproduction of this grape variety in Korean market calls for an alternative product in which excess grapes can be utilized. This study is focused on the determination of the effects of processing time and temperature on the quality components of Campbell grape juice. The results can be a guide to have a processing method that can be used in producing Campbell grape juice with good sensory properties and high bioactive compounds     

ASSESSMENT OF AN EXPONENTIAL MODEL FOR ULTRAFILTRATION OF APPLE JUICE

The clarification of apple juice by ultrafiltration has been commercially used for many years. A common phenomenon in membrane processes is the decline of permeate flux (J) with time (t), called “membrane fouling.” The phenomenon of membrane fouling is very complex and difficult to describe theoretically, and model studies are limited. A number of semiempirical and empirical models have been proposed to explain flux behavior during membrane filtration processes. Using these models, typical t versus J curve observed in membrane filtration applications was examined in two or three periods. However, the boundaries between each period could not be accurately determined and were specific to the system under investigation. Thus, these semiempirical and empirical models are valid only for the system investigated. In this article, the applicability of an exponential model to ultrafiltration of apple juice was studied. The results showed that the exponential model can be successfully applied to analyze the raw filtrate volume V versus t data of ultrafiltration of apple juice, and initial flux J₀, membrane resistance R_m and exponential fouling coefficient k values can easily be determined from the raw data.     

GRAIN SORGHUM WAX AS AN EDIBLE COATING FOR GELATIN-BASED CANDIES1

Gelatin-based candies were coated with medium chain triglyceride (MCT) oil or MCT oil combined with grain sorghum or carnauba wax (8.7% w/w of oil). Compared with uncoated samples, oil/sorghum wax and oil/carnauba wax coatings were equally effective in reducing protein solubility of candies in water (25C) and differences between initial and final diameters of candies subjected to melting. At 0, 5, and 10 days of storage (over calcium sulfate), the candies were evaluated by sensory panelists for surface reflection, pink color, clarity, chalkiness, firmness, adhesiveness, chewiness, cohesiveness, sweetness, sourness, fruit flavor, off-flavor, and aftertaste. Firmness, adhesiveness, chewiness, cohesiveness, and sourness scores increased (P<0.05) linearly with storage time. Samples treated with sorghum or carnauba wax were less shiny, more opaque, chalkier, and had more intense off-flavor and aftertaste than uncoated samples. Samples treated with the laboratory-extracted sorghum wax rated lower than carnauba wax-treated samples for surface reflection, clarity, chalkiness, off-flavor, and aftertaste.     

STORAGE STABILITY OF WINE COOLERS AS INFLUENCED BY JUICE CONTENT AND CITRIC ACID ADDITION1

A study was conducted to examine the effects of citric acid, juice levels, and storage methods on the stability of wine coolers. Four flavors of wine coolers (apple, grape, pineapple, and citrus) were formulated with 10 and 50% fruit juice with each juice level having 0.2 and 0.4% citric acid added. Three storage temperatures were used: cold (3C), room (21C), and elevated (37C). The cold and room temperature storages were for 10 months, and the elevated temperature storage was for 4 months. Chemical analyses were conducted during storage and sensory analyses were conducted after storage. The pineapple coolers with 0.4% citric acid added were the only coolers to be rated with a significantly higher flavor rating over the coolers with 0.2% added. The wine coolers showed changes in color and decreases in pH and carbonation levels. Coolers containing 50% juice levels were less stable during storage and had lower sensory scores than the coolers containing 10% fruit juice. Elevated storage temperature (37C) for 4 months was an acceptable method of evaluating wine cooler stability problems.     

VISCOSITY AND QUALITY OF TOMATO JUICE AS AFFECTED BY PROCESSING METHODS

ABSTRACT

Quality and viscosity of tomato juice is strongly governed by mechanical and thermal abuse during processing. The effect of processing and storage duration on the viscosity and quality parameters of tomato juice was evaluated in the present work. Tomato juice was obtained by two different methods, normal method (NM) and variable method (VM), and was heated by both conventional and microwave hot break treatments. Tomato juice was evaluated for various quality characteristics including precipitate weight ratio, degree of serum separation (DOSS), Brookfield viscosity, lycopene levels, vitamin C, phenols and antioxidant activity. Changes observed in several quality parameters during storage were statistically insignificant. The methods and processing had the greatest contribution toward viscosity, whereas storage duration had no significant effects. Viscosity parameters viz precipitate weight, DOSS and Bostwick consistency revealed that juice processed by VM was more viscous than that of NM, irrespective of the hot break processing used. Ascorbic acid and lycopene content varied significantly with mechanical methods and processing conditions. However, phenolic content and antioxidant activity remained stable. The variable process represents an improvement over the conventional by enabling tomato processors to improve the consistency of the tomato product.

PRACTICAL APPLICATIONS

Quartering or slicing tomatoes followed by hot break processing techniques can significantly improve the quality of tomato juice in terms of reduced degree of serum separation and precipitate weight ratio. The modified technology could be considered as a viable and economical method for small‐ and medium‐scale tomato processors with limited resources and facilities at their disposal.