Character impact odorants of high-heat skim milk powder isolated by simultaneous distillation-extraction.
To identify the character impact odorant of high-heat skim milk powder (HHSMP), a comparative study using ultrahigh-temperature (UHT) milk was performed. Aroma concentrate was prepared by column adsorption combined with simultaneous distillation-extraction. Aroma extract dilution analysis (AEDA) revealed 58 aroma peaks with flavor dilution (FD) factors ranging from 10 to 3000; from these, 41 compounds were identified and 7 compounds were tentatively identified (FD factor > or = 300). Among these HHSMP and UHT milk components, methyl 2-methyl-3-furyl disulfide and bis(2-methyl-3-furyl) disulfide, which appeared to be generated during the processing of each product, were identified. When the results of the AEDA of both samples were compared, it was considered that the characteristic aroma of HHSMP was not explained by a single compound but instead formed from a mixture of several types of compounds contained in common with the UHT milk. The contribution of these compounds to the aroma of HHSMP was confirmed by an aroma simulation experiment.
Contributors to sweet and milky odor attributes of spray-dried skim milk powder
Contributors to sweet and milky odor attributes of spray-dried skim milk powder have been investigated. Spray-dried skim milk was homogenized with water, and the volatiles were isolated by simultaneous steam distillation extraction (SDE). The odor concentrate was fractionated by silica gel TLC. Two polar fractions with sweet and milky odors were analyzed by GC and GC-MS. To elucidate the compounds directly contributing to the characteristic flavor, these fractions were further fractionated by a preparative GC and the separated fractions and peaks were sniffed. Nonanoic acid, decanoic acid, and dodecanoic acid were responsible for a sweet, fatty, and butter-like odor ; undecanoic acid contributed a sweet, and butter-like odor ; and γ-undecalactone, γ-dodecalactone, a γ-lactone, δ-decalactone, and δ-undecalactone gave a sweet and milky odor.
Evaluation and Control of Collapsible Soils
Some compacted soils wetted under certain conditions of compaction and loading may exhibit additional settlement (collapse). To investigate the effect of the soil type, compaction water content, initial dry unit weight and applied pressure at wetting on collapse potential, 138 single‐oedometer tests were conducted on eight different soils. The results indicate that well‐graded soils tend to collapse more than poorly graded ones under similar conditions. Furthermore, collapse potential decreases with an increase in (1) The difference between the sand and clay percentages; (2) compaction water content; and (3) initial dry unit weight, while it increases with pressure at wetting. A multiple regression analysis was performed on the laboratory results to provide a collapse‐predictive model that was substantiated by data reported by several researchers. A chart is presented to estimate (1) The collapse potential of soils under various conditions; and (2) the critical water content beyond which no collapse is ex...