Physicochemical, Microbiological, Aroma, and Flavor Profile of Selected Commercial Sweet Whey Powders

ABSTRACT: Cheddar whey powders from the West Coast, Midwest, and East Coast regions of the United States were analyzed for composition, microbial content, solubility, wettability, hygroscopicity, color, and sensory quality. Seasonal variations were investigated by sampling during both winter and summer. Each sample was analyzed after 3- and 9-mo storage in the original packaging in a controlled environment (21°C, 30% relative humidity). Compositional parameters were within specifications except for calcium content, which was low. The largest variability among processors was observed in free moisture (1.1% to 2.8%) and salt content (2.18% to 4.22%). The microbial content was mostly low although 1 sample had a standard plate count >50000 colony-forming units (CFU)/g, and some variability was observed in the content of spore formers. Large variations were observed in solubility index (from <0.1 to 4.0 mL) and in wettability (from 5 to >300 s). Titratable acidity ranged from 0.098% to 0.295% lactic acid and pH from 5.27 to 6.44. The powders ranged from slightly to extremely hygroscopic. Cooked flavor and aroma were the most intense attributes for all the whey powders. There was suggestive evidence of differences between the winter and summer production in regard to the cooked flavor and aroma, oxidized flavor and aroma, barney aroma, sour and salty taste. This study demonstrates that there are significant differences among commercial whey powders that could impact the application in further processing.     

Volatile components and sensory properties of jujube wine as affected by material preprocessing

Fermented jujube wine, derived from the red jujube berry, has a unique flavor, a mild and sweet taste, and high nutritional value. Among diverse varieties of jujube, Bokjo and the native variety are the most frequently cultivated varieties in Korea. The present study aimed to determine the brewing properties of jujube and to compare the characteristics of fresh and dried fruits of the native and Bokjo varieties for optimal brewing conditions for jujube wine production. We investigated the physicochemical and sensory properties, and we compared the volatile compounds in jujube wine prepared using different methods, through solid-phase microextraction (SPME) GC/MS analysis. The physicochemical properties of jujube wine depended on the drying process rather than the cultivar or the presence of seeds. Sensory properties including aroma and sweetness, which have positive effects on jujube wines, were greater in the whole dried fruit group, while negative properties including grassy aroma, sourness, and bitter taste, were high in the fresh fruit group; these observations contrast their physicochemical properties, as analyzed using dried jujube with seeds. Significant differences were observed in volatile compounds among jujube wine samples. In particular, isoamyl octanoate, isoamyl decanoate, ethyl laurate, ethyl myristate, and 2-phenethyl acetate potentially contribute to the jujube-like flavor of dried jujube wine. These results could be useful as basic data for raw material processing for jujube wine production.     

Effect of grape pre-drying and static pomace contact on physicochemical properties and sensory acceptance of Brazilian (Bordô and Isabel) red wines

Wine quality is evaluated by sensory attributes and physicochemical properties whose relationship is intensely investigated. This work aimed to analyze the physicochemical properties and sensory attributes of wines from Bordô and Isabel American grapes elaborated by a traditional and two novel winemaking processes: pre-drying and submerged static pomace. It was possible to observe significant differences between the samples in all physicochemical properties (P < 0.001), except in volatile acidity. Bordô and Isabel pre-drying wines presented the highest values of dry extract (43.00 and 33.66 g L^?1) in comparison with the other wines which presented dry extract below 30 g L^?1. Furthermore, pre-drying wines showed the highest phenolic content (1340.80 and 908.80 mg L^?1) in comparison with static pomace (998.02 and 433.46 mg L^?1) and traditional treatments (983.96 and 560.26 mg L^?1). Sensory analysis showed significant differences between the samples in all attributes, except in appearance acceptance. Cluster analysis and multidimensional scaling was successfully applied and allowed to observe the relationship between physicochemical properties and sensory attributes. Total phenolic content and color indexes were associated with the appearance of wines, as well as alcohol content and acidity on aroma. The results also revealed the connection between dry extract and total and reducing sugars with the body of wines from innovative vinification. The flavor was associated with several physicochemical properties and also influenced the global acceptance of the samples. The innovative wines showed great acceptance in all sensory attributes, and the employment of these treatments on an industrial scale should be considered once providing wines with unique characteristics.     

The effect of soy protein concentrate addition on the physical, chemical, and sensory properties of strawberry flavored ice cream

The effect of soy protein concentrate (0, 1.5, 3, and 4.5%) on the physical, chemical, and sensory properties of strawberry flavored (0, 0.01 and 0.02%) ice cream samples was examined. All samples were analyzed for pH, titratable acidity, total solids, nitrogen, fat, ash, overrun, viscosity, meltdown, Hunter L-, a-, b- values, flavor, body and texture, and appearance. Substituting soy protein concentrate (SPC) in ice cream formula for non-fat dry milk (NFDM) positively influenced the nitrogen content, viscosity values, and melting and appearance properties of the ice cream samples while overrun values and flavor scores were negatively affected. SPC could be incorporated into the ice cream formula in the range of 1.5–3% devoid of significantly diminishing the physical, chemical, and sensory properties.     

PHYSICAL–CHEMICAL AND SENSORY QUALITY EVALUATION OF GARLIC CULTIVARS

ABSTRACT

Physical–chemical quality of 14 garlic cultivars grown in Spain was analyzed, and the cultivars were classified into three types: purple, white and Chinese, in order to show the possible differences among them. The most useful instrumental color parameter to discriminate among the different types of garlic was lightness (L*). The high pH value of the purple‐type cultivar Moraluz, and the high content of d ‐glucose, d ‐fructose and total sugars of the Chinese‐type cultivars were quite remarkable. The consumer judges preferred the color and pungency of the purple‐type cultivar Morasol, while Chino Sprint stood out for its intense garlic odor. Finally, correlations between the physicochemical and the sensory parameters were studied. The red color intensity was correlated with lightness (L*) and with hue (h*); pH was correlated with chroma (C*) and moisture percentage was correlated with sucrose content.

PRACTICAL APPLICATIONS

One of the main objectives of this work was to advise growers on the selection of garlic seed. The data obtained in this work was sent to a regional research and advising agronomic center (Technical Agronomic Institute, provincial council of Albacete), where advice was given to local growers concerning the selection of the most adequate seeds, in terms of physical– chemical properties and consumer preference, plus agronomic performance (data not included in this article). The conclusions reached in this study will make an important contribution to the agronomic characterization of the garlic cultivars grown in Spain.

     

Characterisation of flavour compounds in Biska – a herbal spirit produced with mistletoe

Mistletoe (Viscum album) is mostly used in its herbal form owing to its content of diverse biologically active substances. In Croatia's Adriatic region, it is used for production of Biska, a strong alcoholic beverage produced by maceration of mistletoe in spirit or brandy, with or without the addition of honey. In this work, Biska was characterised by analysis of aroma compounds and physicochemical parameters and is the first study of the aroma profile of a strong alcoholic beverage produced with mistletoe. The aroma of 14 samples of Biska – five commercial and nine homemade – was analysed using GC/MS with solid‐phase microextraction. A total of 166 aroma compounds were detected. Major components were ethyl esters (medium and long chain fatty acids), fatty alcohols, isopropyl myristate, aldehyde decanal and some terpenes. The distribution of aroma compounds was evaluated by principal component analysis. Some significant differences in physicochemical properties were observed including ethanol concentration (28–44% v/v) and pH (4.4–6.5). Although the colour of Biska was light brown with greenish reflections, there were differences in chromatic parameters. The commercial samples were darker and were less transparent than homemade Biska, perhaps reflecting more extensive maceration/extraction or the addition of caramel. © 2018 The Institute of Brewing & Distilling     

Effect of extrusion conditions on the physicochemical properties of a snack made from purple rice (Hom Nil) and soybean flour blend

Soy flour was added at levels of 5%, 10%, and 15% of Hom Nil rice flour for extrusion at 190 °C barrel temperature and 350 rpm screw speed. The extruded snack qualities decreased inversely with soy flour. However, product qualities were considered to be optimised when soy flour at 5% was added. The effect of feed moisture content (15, 17, 19 g (100 g)^?1 wb), barrel temperature (150, 170, 190 °C) and screw speed (350, 400, 450 rpm) on physicochemical properties of the snack were then investigated. The physicochemical properties of the product including expansion ratio, density, water absorption index (WAI), water solubility index (WSI) and hardness were evaluated. All properties were related, as linear equations, in terms of feed moisture content, barrel temperature, screw speed with relative correlation (R²) at 0.83–0.94. The snack properties along with consumer acceptance were all highest when the extruded condition were 15 g (100 g)^?1 wb feed moisture content, 170 °C of barrel temperature and 450 rpm of screw speed.     

Sodium Tripolyphosphate and Sodium Ascorbate Monophosphate as Inhibitors of Off-flavor Development in Cooked, Vacuum-packaged, Frozen Turkey

Sodium tripolyphosphate (STP) or sodium ascorbate monophosphate (SAsMP) in water solutions (0.3 and 0.5% levels) or water only were added to ground turkey which was cooked, vacuum packaged, and stored frozen. Soapy flavor was higher, but rancid flavor and hexanal and bathophenathroline-chelateable (nonheme) iron contents were lower in samples with phosphate salts. Samples without phosphates contained the greatest amount of bathophenathroline-chelateable iron; samples with 0.5% STP contained the least. The addition of phosphate salts decreased cooking losses and increased moisture but did not affect the fat content. Generally, intensity scores for stale and rancid aroma and flavor attributes were low, < 1 for all samples.     

Mechanical and microstructural properties of soy protein – high amylose corn starch extrudates in relation to physiochemical changes of starch during extrusion

Mechanical and microstructural properties of expanded extrudates prepared from blends of high amylose corn (Zeamays L. ssp. Mays) starch (HACS) and soy protein concentrate (SPC) were studied in relation to the physicochemical changes in starch. Effects of screw speed (230 and 330 rpm) and SPC level (10%, 20%, 30% and 50%) on expansion and mechanical properties were determined. Compared with 230 rpm, screw speed at 330 rpm resulted in increased specific mechanical energy, expansion ratio, water absorption and water solubility indices and decreased bulk density and piece density. Varying screw speeds did not significantly affect the mechanical strength of extrudates or starch molecular weight distribution. Bulk and piece densities, and water absorption index (WAI) only slightly increased or exhibited no significant trends as SPC level increased to 20%. A substantial increase in bulk and piece densities and decrease in expansion ratio and WAI were observed as SPC level increased from 20% to 30%. The trends were either reversed or moderated as SPC increased to 50%. These results in combination with average crushing force and water solubility index data provided a significant insight into the interactions between HACS and SPC during extrusion processing. As compared to an earlier baseline study by our research group on normal corn starch – SPC extrudates, results from the current study indicated that the expansion of extrudate containing HACS alone was lower than that of extrudates containing normal corn starch. However, expansion of the HACS–SPC blends was not significantly impacted at 10–20% SPC levels, whereas the expansion of normal corn starch was significantly reduced.     

Characterization of the aroma compounds in crystal malt

Crystal malt, the most popular type of specialty malt used in beer brewing, plays a vital role in forming complex flavor and color. Nevertheless, crystal malt is only defined based on the malting process, and there is not any standard to evaluate its quality. In the current study, the volatile aroma constituents of commercial crystal malt samples were analyzed with headspace solid-phase microextraction combined with gas chromatography–mass spectrometry, in order to explore the characteristic aroma compounds of crystal malt. The average concentration of volatile aroma compounds in 10 crystal malt samples is 587 µg L⁻¹, ranging from 347 to 1265 µg L⁻¹. A total of 38 aroma compounds were identified, 47% of which were existed in all the 10 samples. Based on principal component analysis and odor activity value, isobutyraldehyde, 2-methylbutanal, furfural, 2-acetyl-1H-pyrrole, oct-1-en-3-ol, 4-methyl-2-phenyl-2-pentenal, and (2E)-2-isopropyl-5-methyl-2-hexenal could be considered the characteristic aroma compounds of crystal malt. The results of this present study would help to establish a standard to assess the quality traits of crystal malt sample.     

Preference Mapping of Fresh Tomatoes Across 3 Stages of Consumption

Tomatoes (Solanum lycoperiscum) are a popular produce choice and provide many bioactive compounds. Consumer choice of tomatoes is influenced by flavor and visual appearance and external texture cues including hand firmness and sliceability. The objective of this study was to determine drivers of liking for fresh tomatoes across 3 stages of consumption. Seven tomato cultivars were ripened to a 6 on the USDA color chart. Trained panelists documented appearance, flavor, and texture attributes of tomatoes in triplicate. Tomato consumers (n = 177) were provided with knives and cutting boards and evaluated tomatoes across 3 stages: appearance (stage 1), slicing (stage 2), and consumption (stage 3). Consumers evaluated overall liking at each stage. Analysis of variance and external preference mapping were conducted. Overall liking was highest during the appearance portion of the test and lowest during the consumption portion (P < 0.05). Drivers of liking at stage 1 were color intensity, even outside color, and overall aroma. Drivers of liking at stage 2 were wetness/juiciness and overall aroma. Wetness/juiciness, seed presence, ripe flavor, and sweet and umami tastes were drivers of liking for tomatoes at consumption (stage 3). Four separate clusters of tomato consumers were identified. Cluster 1 preferred tomatoes with even color, higher color intensity, and flavor intensity. Cluster 2 preferred firm tomatoes. Cluster 3 preferred tomatoes that were soft and at peak ripeness; this cluster also had the highest liking scores for all tomatoes. Cluster 4 consumers generally consumed tomatoes in sandwiches rather than as‐is and preferred tomatoes with even and intense color. Tomato growers can utilize these results to target cultivars that are well liked by consumers.     

EFFECTS OF BLANCHING METHOD ON THE QUALITY CHARACTERISTICS OF FROZEN PEAS

This study evaluated the effects of microwave blanching prior to freezing as an alternative pretreatment for frozen peas. Peas were blanched (steam‐, boiling water immersion‐, microwave‐ or microwave‐blanched in a bag), frozen and evaluated after 0, 6 and 12 weeks for moisture and ascorbic acid content, peroxidase activity, visual appearance and instrumental color, and after 6 and 12 weeks for aroma, flavor and texture. All blanch treatments reduced peroxidase activity by 97% compared with controls (unblanched); blanching methods did not differ. Steam blanching resulted in significantly better ascorbic acid retention than all other treatments; microwave blanch treatments were either equivalent to or better than boiling water immersion. Both microwave treatments darkened (L* value) peas. Microwave‐blanched peas were visually greener than other treatments, but their appearance was less intact. Aroma and flavor were similar among blanch treatments. Texture of boiling water immersed peas was similar to the two microwave treatments.     

Influence of quinoa roasting on sensory and physicochemical properties of allergen‐free,gluten‐free cakes

The objectives of this study were to determine pasting properties of non‐roasted (NR) and roasted quinoa (RQ) and to investigate the effect of RQ on consumer acceptance and physicochemical properties of an allergen‐free, gluten‐free cake formulation. Quinoa seeds were roasted at 177 °C for 15 (R15), 30 (R30) and 45 min (R45), and flours were analysed for pasting properties. Five cakes including a commercial chocolate cake (CCC) and cakes made with NR and RQ flours were evaluated for preference by fifty panelists. Quality parameters included colour, water activity, moisture content, firmness, weight and height. Peak and final viscosity increased with roasting time. The NR cake had the highest sensory scores for appearance, colour and texture. On flavour and overall acceptability, CCC was the highest. Regarding quality data, CCC, NR and R15 cakes had similar L* values, while CCC had the lowest a*, b*, a_w, moisture content and firmness values.     

Evaluation of gum exudates from three selected plant species from Tanzania for food and pharmaceutical applications

Authenticated gum samples from three plant species from Tanzania were analysed and their potential for food, pharmaceutical and other applications was determined by comparing their physicochemical properties with those of commercial Acacia gums from Tanzania, gum karaya and the specifications demanded by the international regulatory bodies for gum arabic for food and pharmaceutical applications. The gum exudate from Dichrostachys cinerea meets some specifications (moisture content, solubility, insoluble matter and ash) demanded for the identity and purity of gum arabic as stipulated by the international regulatory bodies. The aqueous solution of the gum possesses solubility and viscosity similar to commercial gum arabic. Similarly, the properties of Sterculia quinqueloba gum meet a number of the specifications demanded for gum karaya, except that it contains high levels of tannin which would limit its usefulness in food and pharmaceutical applications. The properties of the gum exudate from Acacia pseudofistula, on the other hand, are different from those of Tanzanian commercial Acacia gums. © 2002 Society of Chemical Industry     

Effects of feed moisture and extruder screw speed and temperature on physical characteristics and antioxidant activity of extruded proso millet (Panicum miliaceum) flour

The objective of this work was to determine the impact of extrusion variables [moisture (17–25%), screw speed (170–250 r.p.m.) and temperature (90–150 °C)] on the physical properties and antioxidant activity of proso millet extrudates. Extrusion variables were adjusted using an inscribed central composite rotatable design. Response variables were bulk density (BD), radial expansion ratio, water absorption index, water solubility index, hardness, colour (L*, a*, b*) and antioxidant activity. Moisture and screw speed were the most influential variables affecting millet extrusion: their linear, quadratic and interaction terms accounted for more than 50% of the variability in all responses except for b*. Expansion was greatest at severe conditions of low moisture and high screw speed. These conditions were also consistent with the highest antioxidant activity. This study demonstrated that high expansion and antioxidant activity can be obtained by extruding proso millet under low moisture and high screw speed conditions.     

Proteolysis,Texture, and Sensory Characteristics of Serrano Hams from Duroc and Large White Pigs during Dry‐Curing

Proteolysis, texture, physicochemical, and sensory characteristics of Serrano hams from Duroc and Large White pigs at 5, 7, 9, 12, and 15 m of curing (3 hams per breed per curing time) were investigated. Higher concentrations of some sarcoplasmic and myofibrillar proteins, peptides with molecular mass in the ranges 3700 to 12000 Da, 700 to 2000 Da, and below 450 Da, and total free amino acids were recorded for Large White hams, while hydrophobic peptides were at higher levels in Duroc hams. A 40 kDa peak in the low‐ionic‐strength soluble protein fraction and 2 peaks of 40 and 45 kDa in the high‐ionic‐strength soluble protein fraction found only in Duroc hams could be of use in discriminating products from different breeds. Physicochemical and textural characteristics of both types of hams evolved similarly during curing and differences in organoleptic traits between breeds were negligible. Flavor intensity and flavor quality of hams were strongly correlated to curing time, with r² values over 0.95 for flavor intensity and over 0.90 for flavor quality, and to the concentration of total free amino acids, with r² values over 0.90 for both flavor intensity and flavor quality. The sensory evaluation scores of Duroc hams, at least as high as those of Large White hams, make the production of high‐quality Serrano ham from pure breed Duroc pigs feasible. Practical Application: Duroc breed crosses are advantageous in the production of dry‐cured hams, resulting in higher marbling, enhanced flavor and lower processing losses, but the characteristics of pure breed Duroc hams have not been investigated. The similar evolution of the compositional, proteolytic, textural, and sensory characteristics of Serrano hams from Duroc and Large White pigs during dry‐curing recorded in the present work makes the production of high‐quality dry‐cured hams from pure breed Duroc pigs feasible. Three protein peaks found only in Duroc hams can be of use to discriminate products from different breeds.     

Untersuchung von aromaaktiven Biosyntheseprodukten von Basidiomyceten auf Reststoffströmen der Lebensmittelindustrie

Biotechnological production of flavors is economically relevant and a key to enable a tasty and diverse food supply. Fungi are suitable biocatalysts for the production of flavor compounds and often more efficient than the classical flavor extraction from plants and foods. Fungi from the department of Basidiomycota have a powerful enzymatic toolbox to generate flavor compounds. Based on a broad screening of Basidiomycota, media optimization was performed to find suitable conditions for an efficient biotransformation of black currant pomace. During fermentation, the scents were investigated on a sensory and instrumental level via gas chromatography-mass spectrometry (GCMS). W. cocos was grown on a solid-state medium composed of 30 g kg^-1 pomace, 6.24 g kg^-1 sodium aspartate-monohydrate and 30 g kg^-1 agaragar for 10 days. Tue flavor was characterized by means of a self-validated aroma dilution analysis (ADA), quantified, and proven with recombination experiments. Solid-state fermentation of pomace and aspartate led to a pleasant odor reminiscent of wild strawberries. Methyl anthranilate (2,206 μg kg^-1, flavor dilution factor 210), (R)-linalool (1,879 μg kg^-1, 2¹¹), 2-amino benzaldehyde (771 μg kg^-1, 2⁵), and geraniol (138 μg kg^-1, 2⁵) were determined as aromarelevant for the wild strawberry like flavor in recombination experiments. Tue substrate-fungus combination made use of the nutrients provided by the black currant pomace leading to an appealing natural flavoring for food. In a second approach, 80 g L^-1 pomace and 60 g L^-1 sucrose (pH 4.4) were fermented in a submerged culture until the medium reached a pH-value of 3.5. Supernatants of the fermented product were evaluated for a potential use as a beverage. Submerged fermentation of black currant pomace and sucrose led to a pleasant flowery and honey-like odor and a fruity, slightly sour taste. Tue produced fruit acids and flavor compounds were characterized and quantified. Tue scaled-up fermentation product was processed and carbonized in cooperation with the Geisenheim University. A panel evaluated the carbonated fermented beverage on a hedonic scale, ranging from O to 10, with 8.0 ± 1.4, whereas the value for the non-inoculated medium was 2.5 ± 2.5. A rise of the oxalic acid concentration was detected, which led to the characteristic fruity taste in combination with citric acid (935 mg L^-1 citric acid and 192 mg L^-1 oxalic acid). Linalool (23 μg L^-1), geraniol (42 μg L^-1), phenylacetic acid (950 μg L^-1), eugenol (23 μg L^-1) and methyl phenylacetate (94 μg L^-1) were detected with odor activity values above one, which imparted fruity and honey-like odors. Fermentation of black currant pomace led to a tasty beverage, which suits the current beverage trends. Upcycling of pomace with its physiologically valuable nutrients as a fermented beverage could contribute to a healthy human nutrition. In a third study, 28 potentially aroma active non-canonical terpenes were investigated in cooperation with the Dechema Research Institute. For twelve especially potent compounds, the odor thresholds (OT) were determined in comparison to their non-methylated equivalents. In addition to the classical approach according to Ullrich and Grosch (1987), a novel method including the individual OT determination of the internal standards was established. Tue odors of several non-canonical terpenes were described for the first time. Twelve compounds were identified as highly intense flavors, e.g., the flowery smelling 2-methyllinalool with an OT of 1.8 ng L^-1 air, the earthy smelling 2- methyl-a-fenchol (3.6 ng L^-1 air), and the flowery scent 2-methylgeraniol (5.4 ng L^-1 air). The newly developed method for the OT determination appeared as an improvement compared to the method used so far. Methylated derivatives of linalool, citronellol, and geraniol were highly attractive due to their flowery and citruslike scents, which are highly interesting for the cosmetic industry.