Effects of derivatization coupled with GC-FID analysis of cholesterol in some bakery products.

Cholesterol analysis by derivatization technique is a time consuming, costly, and complex process while analyzing cholesterol without derivation is a simple, and quick method.Researchers analyzed cholesterol using both derivatization and non-derivatization techniques successfully. The objective of this study was to investigate the effect of derivatization in cholesterol analysis particularly on bakery goods.The retention time of non-derivatized cholesterol (11.62 min) and non-derivatized α-tocopherol standard (11.60 min) was very close in HP-5 capillary GC column andthey eluted together while injected as mixed standard. As a result, cholesterol content determined by non-derivatized technique could be overestimated due to the presence of α-tocopherol inbakery products. The peak resolution (Rs) between derivatized cholesterol and derivatized α-tocopherol standard using the appliedgradient GC condition was 3.1 which is well separated (>1.5) based on AOAC guidelines. The derivatized gas chromatographic cholesterol analysis method was verified by limit of detection (LOD; 0.03 mg/100 g), limit of quantification (LOQ; 0.08 mg/100 g), linearity (R2; 0.999),precision (repeatability: relative standard deviation (RSD) 1.5 %; reproducibility: RSD 1.9 %), and accuracy (102.1 % recovery). The verified cholesterol analysis method was subsequently applied to determine cholesterol content in selected bakery items, yielding a range of 2.76 ± 0.06 mg/100 g (chrysanthemum bread) to 114.26 ± 4.72 mg/100 g (castella).

Biochemical investigation of Bangladeshi black tea and their correlation to organoleptic quality evaluation.

Black tea samples were investigated for theaflavin (TF), thearubigin (TR), highly polymerized substances (HPS), total liquor color (TLC), color index (CI), caffeine (CAF), total polyphenol content (TPC), antioxidant activity (DPPH) and organoleptic evaluation. The objectives of the study was to perform the biochemical analysis and organoleptic test of various black tea and develop a correlation between them. Overall correlation study showed that TF:TR and total liquor color, are significantly (p < 0.01) and positively correlated with the total quality score where the correlation coefficient was 0.970 and 0.969 respectively. Additionally, statistical analysis revealed a significant (p < 0.01) and positive correlation between total phenol contents and antioxidant scavenging activity (0.986), supporting the notion that TPC accounts for most of the antioxidants in tea extract. Qualitative characteristics and organoleptic tests were shown identical outcomes in this study.

Antioxidative Properties of Machine-Drip Tea Prepared with Citrus Fruit Peels Are Affected by the Type of Fruit and Drying Method.

Citrus peels are generally discarded as waste, although they are rich sources of health-promoting compounds. This study investigated the properties of citrus peels for development as a potential functional tea ingredient. Three citrus peel powders (DCPPs, Cheonhyehyang, Hallabong, and orange) which were dried by air- and freeze-drying, were used to prepare machine-drip tea. Then, total polyphenol compounds (TPCs), flavonoids, and the DPPH radical scavenging activity of DCPPs and teas were evaluated. Freeze-dried DCPPs had relatively higher TPC s (16.47-21.11 mg GAE/g) and DPPH radical scavenging activity (3.25-16.43 mg GAE/g) than air-dried DCPPs; TPCs (14.06-19.12 mg GAE/g) and DPPH radical scavenging activity (1.80-3.22 mg GAE/g). In contrast, air-dried DCPPs were more effective in machine-drip teas, showing a higher range of TPCs (50.64-85.12 mg GAE/100 mL) and DPPH radical scavenging activity (1.05-3.86 mg GAE/100 mL) than freeze-dried DCPPs; TPCs (40.44-46.69 mg GAE/100 mL) and DPPH radical scavenging activity (0.56-1.08 mg GAE/100 mL). Among citrus varieties, Cheonhyehyang had the highest TPCs and DPPH radical scavenging activity in both DCPP and tea. Four flavonoids (Hesperidin, Naringin, Nobiletin, and Tangeretin) mainly existed in citrus peels. The amount of hesperidin was highest; therefore, Hallabong and orange exhibited higher total flavonoid contents. However, freeze-dried Cheonhyehyang peel and air-dried Cheonhyehyang tea, which showed the highest TPCs and DPPH radical scavenging activity, had higher nobiletin and tangeretin. This implies that nobiletin and tangeretin strongly influenced the antioxidant activity of citrus peels with TPC. This research provides essential information for the tea industry looking for functional ingredients. In addition, it helps to reduce by-products by using citrus peel powders.

Effect of oximation reagents on gas chromatographic separation of eight different kinds of mono- and di-saccharides.

The objective of this study was to investigate the effect of oximation reagents in simultaneous analysis of mono and di-saccharides using gas chromatography. Sugar oximation with O-ethylhydroxylamine separated all the mono- and di-saccharides while hydroxylamine and O-benzylhydroxylamine could make most of the saccharides separable except for xylose and arabinose. Resolution of xylose: arabinose, galactose: glucose, and fructose: galactose oximated by O-ethylhydroxylamine in DB-1ms column were 1.66, 2.15, and 6.19, respectively, which were above 1.5 and were officially acceptable for quantitative analysis according to the AOAC guideline. The applied method was then verified by the method validation parameters; LOD (0.011-0.02 mg/100 g), LOQ (0.032-0.061 mg/100 g), linearity (R2 = 0.9991-1.0000) and precision (repeatability RSD: 1.4-3.3%, reproducibility RSD: 1.7-7.6%). The greatest amounts of xylose (19.03 ± 0.38 mg/100 g), maltose (6,274.48 ± 173.59 mg/100 g) were found in the oyster sauce, and the contents of glucose (10,565.00 ± 125.31 mg/100 g), galactose (170.40 ± 4.62 mg/100 g) were greatest in soybean paste.