Yazar "Drake, MA" seçeneğine göre listele

Listeleniyor 1 - 4 / 4
  • [ X ]
    Öğe
    Characteristic aroma components of rennet casein
    (Amer Chemical Soc, 2003) Karagül-Yüceer, Y; Vlahovich, KN; Drake, MA; Cadwallader, KR
    Rennet casein, produced by enzymatic (rennet) precipitation of casein from pasteurized skim milk, is used in both industrial (technical) and food applications. The flavor of rennet casein powder is an important quality parameter; however, the product often contains an odor described as like that of animal/wet dog. Two commercial rennet casein powders were evaluated to determine the compounds responsible for the typical odor. Aroma extracts were prepared by high-vacuum distillation of direct solvent (ether) extracts and analyzed by gas chromatography-olfactometry (GCO), aroma extract dilution analysis (AEDA), and GC-mass spectrometry (MS). Odorants detected by GCO were typical of those previously reported in skim milk powders and consisted mainly of short-chain volatile acids, phenolic compounds, lactones, and furanones. Results of AEDA indicated o-aminoacetophenone to be a potent odorant; however, sensory descriptive sensory analysis of model aroma systems revealed that the typical odor of rennet casein was principally caused by hexanoic acid, indole, guaiacol, and p-cresol.
  • [ X ]
    Öğe
    Characterization of nutty flavor in Cheddar cheese
    (Elsevier Science Inc, 2004) Avsar, YK; Karagul-Yuceer, Y; Drake, MA; Singh, TK; Yoon, Y; Cadwallader, KR
    The objectives of this study were to determine the volatile components responsible for the sensory perception of nutty flavor in Cheddar cheese. Cheddar cheeses with and without nutty flavors were selected by descriptive sensory analysis. Volatile aroma components from Cheddar cheeses with and without nutty flavors were isolated and characterized using solvent extraction with high vacuum distillation, dynamic headspace analysis, gas chromatography-olfactometry, and gas chromatography-mass spectrometry. More than 50 aroma-active compounds were detected in Cheddar cheeses. Consistent differences were observed between nutty and not nutty Cheddar cheeses. Strecker aldehydes were detected in higher amounts in Cheddar cheeses with nutty flavors compared with Cheddar cheeses without nutty flavors. Strecker aldehydes, dimethyl sulfide, and propionic acid were evaluated in young and aged Cheddar cheese models for nutty flavor by descriptive sensory analysis. Dimethyl sulfide and propionic acid did not contribute to nutty flavor in Cheddar cheese. The addition of Strecker aldehydes to young (<4 mo old) Cheddar cheese models resulted in nutty/malty flavor perceived by sensory analysis. When Strecker aldehydes were incorporated into aged (>9 mo old) Cheddar cheese models, nutty flavor perception increased. Strecker aldehydes contribute to nutty flavor in aged Cheddar cheese.
  • [ X ]
    Öğe
    Evaluation of the character impact odorants in skim milk powder by sensory studies on model mixtures
    (Wiley, 2004) Karagül-Yüceer, Y; Drake, MA; Cadwallader, KR
    The objective of this study was to verify key aroma-active compounds responsible for reconstituted fresh skim milk powder (SMP) aroma using threshold analysis, odor activity values, and model systems. Twelve odor-active compounds of SMP and one odor-active compound from fluid milk were selected based on flavor dilution factors from gas chromatography-olfactometry. Thresholds for the 13 odor-active compounds were identified using five-set ascending forced choice threshold analysis in odor-free water and fluid skim milk. Model systems were prepared using rehydrated milk retentate (RMR). The aroma of each model was evaluated by descriptive sensory analysis and by difference-from-control testing using a trained panel. The aroma of reconstituted fresh SMP and liquid skim milk were used as controls. Models containing a mixture of twelve of the thirteen chemicals had the most similar odor characteristics to rehydrated SMP aroma (9.0/10) indicating that these compounds constitute the character impact odorants of rehydrated fresh SMP.
  • [ X ]
    Öğe
    Identification and quantification of character aroma components in fresh Chevre-style goat cheese
    (Wiley, 2003) Whetstine, MEC; Karagul-Yuceer, Y; Avsar, YK; Drake, MA
    Chevre-style goat cheeses were characterized by descriptive sensory analysis as exhibiting sweet dairy flavors as well as a characteristic waxy/animal flavor. Aroma-active compounds (> 80) with high intensities identified by gas chromatography/olfactometry and gas chromatography/mass spectrometry included 2,3-butanedione (buttery), 1-octen-3-one (mushroom), o-aminoacetophenone (grape), lactones (coconut, peach), octanoic acid (sour/waxy), as well as 4-methyl and 4-ethyl octanoic acids (waxy/animal). Subsequent sensory analysis with model cheese systems confirmed that 4-methyl and 4-ethyl octanoic acids were responsible for the characteristic waxy/animal flavor.