Association Of Official Analytical Chemists Research Articles

A Novel Integrative Methodology for Research on Pot-honey Variations During Post-harvest

This novel review of analytical methods for pot-honey research was intended to provide concise references to a 35-day post-harvest experiments at 30 °C, in an integrated study. Diverse methods were selected from specialized literature, from the AOAC (Association of Official Analytical Chemists), and the International Honey Commission. Besides the geographical and seasonal origin, the pot-honey I.D. consists of entomological and botanical identifications, the latter performed by acetolyzed or natural melissopalynology. The methods of this integrative study included: 1. Physicochemical analysis (Aw, color, moisture, pH, free acidity, lactone acidity, total acidity, hydroxymethylfurfural (HMF), and sugars by highperformance liquid chromatography HPLC), 2. Targeted proton nuclear magnetic resonance 1H-NMR metabolomics (sugars, ethanol, HMF, aliphatic organic acids, amino acids, and botanical markers), 3. Biochemical composition (flavonoids, polyphenols), 4. Antioxidant activity (ABTS 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid-free radical scavenging assay, DPPH 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay, ferric reduction assay FRAP), 5. Microbial counts (aerobic plate, yeast and mold, Bacillus, and lactic acid bacteria count), 6. Honey microbiome profiling via independent-culture method: high-throughput bacteria and fungi based on amplicon sequencing approaches, 7. Sensory evaluation (odor, aroma, taste, persistence), and 8. Honey authenticity and biosurfactant tests by an interphase emulsion. A further section was included to provide basic information on the results obtained using each method. This was needed to explain the interacting components derived from pot-honey processing within the stingless bee nest and post-harvest transformations.

A Novel Integrative Methodology for Research on Pot-honey Variations During Post-harvest

This novel review of analytical methods for pot-honey research was intended to provide concise references to a 35-day post-harvest experiments at 30 °C, in an integrated study. Diverse methods were selected from specialized literature, from the AOAC (Association of Official Analytical Chemists), and the International Honey Commission. Besides the geographical and seasonal origin, the pot-honey I.D. consists of entomological and botanical identifications, the latter performed by acetolyzed or natural melissopalynology. The methods of this integrative study included: 1. Physicochemical analysis (Aw, color, moisture, pH, free acidity, lactone acidity, total acidity, hydroxymethylfurfural (HMF), and sugars by highperformance liquid chromatography HPLC), 2. Targeted proton nuclear magnetic resonance 1H-NMR metabolomics (sugars, ethanol, HMF, aliphatic organic acids, amino acids, and botanical markers), 3. Biochemical composition (flavonoids, polyphenols), 4. Antioxidant activity (ABTS 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid-free radical scavenging assay, DPPH 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay, ferric reduction assay FRAP), 5. Microbial counts (aerobic plate, yeast and mold, Bacillus, and lactic acid bacteria count), 6. Honey microbiome profiling via independent-culture method: high-throughput bacteria and fungi based on amplicon sequencing approaches, 7. Sensory evaluation (odor, aroma, taste, persistence), and 8. Honey authenticity and biosurfactant tests by an interphase emulsion. A further section was included to provide basic information on the results obtained using each method. This was needed to explain the interacting components derived from pot-honey processing within the stingless bee nest and post-harvest transformations.

Proximate Composition, Qualitative Phytochemical Screening and In-Vitro Antioxidant Potential of Triumfetta rhomboidea Leaves Extracts

Continuous exploration of medicinal plants for bioactive constituents is essential since the availability and activities of these compounds speaks volume of their possible medicinal benefits. This study evaluated the proximate composition, phytochemical constituents and antioxidant potential of Triumfetta rhomboidea leaf extract. Extraction of aqueous (AETR) and ethanol (EETR) extract were performed by maceration. Proximate composition of pulverized leaf sample was performed following Association of Official Analytical Chemists (AOAC) standards. Antioxidant capacity of extracts were evaluated by determining the total phenolics content (TPC), total flavonoid content (TFC), total antioxidant capacity (TAC), ferric reducing antioxidant power (FRAP) scavenging ability, reducing power (RP) and lipid peroxidation inhibition. Results of proximate analysis revealed 11.01 % moisture content, 3.38 % ash content, 15.15 % crude fiber, 7.34 % crude fat, 61.09 % carbohydrate content, 17.18 % protein content and 379.14 kJ energy value. The total phenol content in aqueous and ethanol extracts were 20.36 ± 0.27 and 12.66 ± 0.28 mg GAE/g, respectively. Total flavonoid was 18.18 ± 1.02 mg QE/g for aqueous and 22.27 ± 0.26 mg QE/g for ethanol extracts with antioxidant capacity of 16.34 ± 4.92 mg AAE/100 g and 48.16 ± 8.50 mg AAE/100 g, respectively. AETR demonstrated highest Fe (II) reducing ability with IC50 of 0.33 ± 0.04 and 0.36 ± 0.04 mg/mL for FRAP and RP activities. This study has demonstrated that T. rhomboidea leave possess biologically active constituents and could presumably perform free radical scavenging activities in reactive oxygen species related diseases. HIGHLIGHTS Triumfetta rhomboidea leaves demonstrated remarkable proximate composition and high energy value The aqueous extract demonstrated high saponin content compared to ethanol extract Aqueous solution (distilled water) has better extraction efficiency of phenolic compounds in leaves of Triumfetta rhomboidea compared to ethanol The aqueous extract exhibited high antioxidant potential compared to ethanol extract as revealed by the ferric reducing antioxidant power and reducing power GRAPHICAL ABSTRACT

Less is more: Vital roles of bioactive equivalency in assessing food quality

Less is more: Vital roles of bioactive equivalency in assessing food quality

LC-MS/MS를 이용한 건강기능식품 중 아스타잔틴 분석법 연구

The Ministry of Food and Drug Safety is amending its test methods for dietary supplements (functional health food) to establish regulatory standards and specifications in Korea. In this regard, we continue to research analytical method development for the items to improve their sensitivity and selectivity. In this study, we have developed liquid chromatographic-tandem mass spectrometry for astaxanthin analysis. This method can be used to characterize and quantify dietary supplement formulations containing astaxanthin. The procedure was validated at 37.5-2,400 ng/mL. Standard calibration curves presented linearity with the coefficient of determination (r²)>0.999. The limits of detection and limits of quantitation were 16 and 49 ng/mL, respectively. The recovery results ranged between 91.9-97.4% at three different concentration levels with relative standard deviations (RSDs) of less than 3.6%. The precision results (RSDs) were obtained between 1.2-3.5%, and reproducibility (1.8%) was obtained. These are in accordance with the established validation criteria (Association of Official Analytical Chemists). Our research can provide scientific evidence to amend the astaxanthin test method for Health Functional Food Codes.

The antibacterial activity and biochemical composition of Adansonia Digitata edible parts

PurposeWithin the framework of the valorization of natural resources, a characterization of the biochemical composition of the edible parts of Adansonia Digitata is applied. The antibacterial effect against bacteria is also realized and compared to some synthetic antibiotics.Design/methodology/approachThe biochemical characterization is carried out according to the norms of the French Association of Normalization, methods of Association of Official Analytical Chemists (AOAC International) and gas chromatography (GC). The antibacterial activity is tested by disk diffusion on a solid medium. Parametric tests are used to compare the differences between groups and heat maps to show the expression of the mean inhibitions according to the studied parameters. Multivariate logistic modeling is applied to study the effect of extracts and antibiotics on bacteria.FindingsBiochemical characterization showed a variable importance of proteins, fibers and total sugars, with the presence of highly desired fatty acids such as palmitic, oleic, stearic, linoleic and a-linolenic acids. This gives the tested parts important energy values, especially in the seeds very rich in fatty acids. Methanol proved to be a better extraction solvent than dichloromethane. Antibacterial activity showed that pulp and leaves extracted with methanol had quite similar inhibitory activities against Enterococcus faecalis ATCC29212 and that this effect was better than some antibiotics. Multivariate analysis showed that the leaves had a similar effect to antibiotics, and a significant effect against Staphylococcus aureus ATCC29213.Originality/valueThis important activity and the attractive nutritional value of this plant could justify its extensive use in the traditional pharmacopoeia.

Salty and Savoury Snacks Compliance with 2016 and 2019 Sodium Content Targets-Durban Market, South Africa.

South Africans consume a significantly high amount of sodium from salty snacks. The study aimed to evaluate savoury snacks (ready-to-eat savoury snacks, flavoured potato crisps and flavoured ready-to-eat, savoury snacks and potato crisps-salt and vinegar only) for compliance with the June 2016 and 2019 target date for sodium reduction as set out by the Department of Health in Regulation 214. It also looked at low-sodium claims made by the evaluated products. The study's research problem is located at the confluence of three critical trends: increasing consumption of sodium-containing salty snacks, increasing sodium-related disease burden and deaths and attempts to regulate sodium intake through regulation as a response. A total sample of 90 products belonging to the above categories was considered. Sodium content information was collected from the selected product packages. The study also applied the Association of Official Analytical Chemists' (AOAC) official method 984.27 in laboratory tests to verify low-sodium claims on the sampled products. The study showed that out of the 90 selected snacks, 26% of the snacks did not meet their 2019 targets, while 4% did not meet their 2016 targets. Fisher's exact tests showed that no snack category had a better inclination toward meeting 2019 tests than others. The laboratory tests showed that 4.4% of the products made a compliant low-sodium content claim (sodium levels below 120 mg Na/100 g), while one made a non-compliant sodium content claim. Among other things, the study recommended increased product compliance monitoring and evaluation, using standardised, rigorous sodium testing and measuring systems, using more consumer-friendly labels and consumer education on sodium labelling.

Assessment of Biologically Active Components and Nutritional Contents of Seed Kernels of Opioro and Julie Mango Varieties: A Right Step for Drug Discovery

This study was aimed at investigating the biologically active compounds and nutritional compositions in the seed kernels of Opioro and Julie varieties with medicinal qualities. The seed kernels were milled, dissolved in methanol and concentrated with rotary evaporator. The chemical compounds in these extracts were analyzed with Gas Chromatography and Mass Spectrometry while the mineral and proximate compounds were assessed with the methods of the Association of Official Analytical Chemists (AOAC). Both Opioro and Julie did not contain similar chemical compounds. A total of 22 chemical compounds were obtained from Opioro while only 13 compounds were discovered in Julie. Five bioactive compounds from Opioro namely cholest-5-en-3-ol, (3.alpha.) (31.63%), 2-Pyridinamine, N-(4,5-dihydro-5-methyl-2-thiazolyl)-3-methyl- (14.74%), 2-Methyl-7-phenylindole (6.96%), benzo[h]quinoline, 2,4-dimethyl (6.61%) and 7-Methyl -2-phenyl-1H-indole (4.27%) were abundant. In Julie, only Octadecanoic acid, 6-Octadecenoic acid, 1, 2, 3-Benzenetriol and n-Hexadecanoic acid were plentiful with the highest peak percentage of 39.76%, 16.05% and 5.41% respectively. The protein, fibre, moisture and ash contents from Opioro and Julie were not significantly different but, the carbohydrates varied (P<0.05) between 71.36±0.37% and 70.22±0.44% and fats varied (P<0.05) between 7.20±0.48% and 9.21±0.31% respectively. Phosphorus (1610.00±14.00 ppm), calcium (4595.00±7.07 ppm), and magnesium (1984.50±21.92 ppm) were high in Julie while zinc (18.197±0.25), copper (14.960±0.09), iron (319.615±2.28) and manganese (337.940±5.80) were more in Opioro than Julie. The seed kernels of Opioro and Julie have abundant bioactive compounds with medicinal properties. The essential mineral elements and rich proximate compounds in both extracts are potentially required and can be capable of improving the health and nutritional conditions of both humans and animals.

Proximate, Vitamins, Minerals and Anti-Nutritive Constituents of the Leaf and Stem of Helichrysum odoratissimum (L.) Sweet: A Folk Medicinal Plant in South Africa

Helichrysum odoratissimum (L.) Sweet (Asteraceae) is a perennial shrub used in South African folk medicine to combat human diseases such as diabetes, coughs, asthma, and diarrhoea, and for wound treatment. This study evaluated the leaf and stem of H. odoratissimum for their nutritive and anti-nutritive qualities using the standard methods of the Association of Official Analytical Chemists (AOAC), atomic absorption spectrometry (AAS) and colorimetry. Crude fat and protein were high in the leaf (7.61% and 7.82% DW), but low in the stem (2.25% and 3.4%), respectively. The neutral detergent fibre (NDF) content was significantly higher in the stem (68.5%) compared to the leaf (43.6%), while non-fibre carbohydrate (NFC) in the leaf (24.93%) was higher than in the stem (15.67%). Mineral analysis showed that both the leaf and stem of H. odoratissimum are good sources of potassium, calcium, sodium, magnesium, phosphorus and iron. Appreciable amounts of vitamins B2, C and E in the leaf and stem supports the folkloric utility of the plant in the traditional treatment of wounds, coughs and colds. A tolerable amount of phytate in both leaf (0.36%) and stem (1.06%) might be a factor for safer consumption of the plant as food and medicine. These findings suggest the use of the plant as a source for dietary supplementation and ethnomedicinal applications.

Determination of Ethanol Content in Water Kefir Using Headspace Gas Chromatography With Mass Spectrometry Detection: Matrix Extension and Methanol Characterization.

Water kefir is a fermented beverage using water, sugar, and cultured microorganism grains as the primary ingredients. Ethanol may be present at varying levels within the final product due to the fermentation process, so it is vital to have a validated method to meet regulatory, quality, and safety requirements. This study describes using water kefir as a matrix for the evaluation of the previously validated method employing headspace gas chromatography mass spectrometry (HS-GCMS) detection for ethanol in kombucha. The study objective is to demonstrate the method originally using kombucha is also fit for the analysis of water kefir. This method will also evaluate the determination of methanol within the water kefir samples. The matrix extension study was performed as per the AOAC INTERNATIONAL guidance documents outlined in Appendix K: Guidelines for Dietary Supplements and Botanicals using HS-GCMS for ethanol determination. Ethanol determination in each water kefir sample is quantified against an external standard calibration curve. The same instrumentation is used for methanol characterization. RSDr and HorRat values obtained for from the study demonstrated acceptable precision with RSDr values of 1.03 to 6.68% and HorRat values determined to be between 0.23 and 1.52 for ethanol determination within kefir samples. Similarly, acceptable values of RSDr ranging from 1.45 to 3.39% and HorRat ranging from 0.25 to 0.49 were observed with methanol determination. For methanol determination, the limit of detection (LOD) and limit of quantification (LOQ) determined for the method in this study to be 16 and 21 ppm, respectively. The methanol spike recovery study gave overall recoveries ranging from 89 to 91%, demonstrating acceptable method accuracy. The results of this study demonstrate the previously validated HS-GCMS method for ethanol determination in kombucha can also be used to quantify ethanol in water kefir samples. The method is also suitable for the determination of methanol within water kefir samples. A straightforward method has been adapted to include the the quantification of ethanol and methanol in fermented beverages such as Water Kefir samples.

Nutritional composition of some selected, unprocessed amaranth grain (Amaranthus spp) varieties in Nigeria

The Amaranth grain is highly nutritious, yet it is hardly utilized in Nigeria. This study seeks to evaluate the nutritional composition of the various Amaranth grains available locally within the country. Five identified varieties were obtained from a research institute in Nigeria and a variety from the market in Ondo State, Nigeria. The six varieties were sorted separately and cleaned manually prior to grinding into flour and then subjected to chemical analysis which included proximate content, minerals, and anti-nutritional composition. An investigation of the constituting proximate, minerals and anti-nutritional compositions of the grain flours was conducted, using standard procedures. Proximate composition was determined using the Association of Official Analytical Chemists (AOAC) methods, carbohydrates were determined by difference, energy content was determined using bomb calorimetry model, mineral analysis were done using atomic absorption spectrophotometer and flame photometer while the anti-nutrients were determined using potassium permanganate titration method and spectrophotometrically. The results were analyzed using ANOVA (p ˂ 0.05) which showed significant difference between the moisture content of the market sample and other types (9.50 – 12.13%). Also, the fat and crude fibre contents of Amaranth grain flour ranged from 5.84 to 21.06 % and 0.61 to 2.07 %, respectively. Though the protein contents of the flour samples were not significantly different (14.36 – 16.03%) from each other, the mineral composition (calcium 193.34 – 247.91 mg/100g, magnesium, 65.59 – 73.48 mg/100g, manganese 6.13 – 13.24 mg/100g, sodium 360 – 435 mg/100g) was relatively high. The anti–nutrient composition showed that the varieties were low in phytate and the values ranged from 0.21 –1.74 mg/100g, the oxalate level of the varieties averaged 15.02 mg/100g for the six samples, the tannin level ranged from 9954.6 to 13565 mg/100g. The study showed that Amaranth grain flour is potentially a food commodity item for value addition either by its lone use or in composite flour formulation. Key words: Amaranth grain flour, Proximate analysis, Protein content, Minerals, Anti–nutrients, Nigeria

Rheological and Physicochemical Analysis of Nonedible Oils Used for Biodiesel Production.

Rheological and physicochemical characteristics of edible oils used for biodiesel production are well established; nonetheless, the rheological and physicochemical characteristics of nonedible oils are yet to be established. The present study therefore focuses on rheological and physicochemical characterization of nonedible vegetable oils that can be used as biodiesel feedstock. The selected vegetable oils studied include cashew nut shell liquid (CNSL), castor oil (CO), Croton megalocarpus oil (CMO), Podocarpus usambarensis oil (PUO), and Thevetia peruviana oil (TPO). Physicochemical parameters analyzed were free fatty acids, acid value, saponification value, peroxide value, iodine value, specific gravity, and moisture content using methods by the Association of Official Analytical Chemists (AOAC). Rheological properties were analyzed using a VT-550 Thermo Haake Viscotester operated by the Rheowin 3 Job Manager software. The preset parameters in the Viscotester were shear rate and temperature. The shear rate increased uniformly from 5 to 100 s–1 at the temperature range of 30–60 °C. The experimental data were fitted into rheological models of Newton, Bingham, Ostwald–de Waele (power-law), and Herschel–Bulkley using Rheowin 3 Data Manager. The oil yield was 29–65%, highlighting the feedstock’s potential for commercial biodiesel production. At a constant temperature, all oil samples exhibited a Newtonian flow behavior. In contrast to edible oils, nonedible oils exhibited high shear stress, emphasizing the reconstruction of new appropriate designs of production systems. The rheological models appropriate to represent the flow behavior of the samples were the Newton and Ostwald–de Waele models, with a fit of R2 = 0.990–1.000.

Proximate Composition, Mineral Element Profile and Antioxidant Properties of the Edible Kenyan Mushroom, Auricularia polytricha

The indigenous Kenyan Auricularia polytricha is a known delicacy to the communities residing around Kakamega forest in Western Kenya. The objective of the present study was to carry out proximate analysis, determine selected mineral element levels and radical scavenging capacity of the fruiting bodies of Auricularia polytricha. Proximate analysis which included determination of total carbohydrates, crude protein, crude fibre, crude fat, ash and moisture contents was done according to the Association of Official Analytical Chemists (AOAC) methods. The minerals (Ca, Mg, Fe, Zn, Mn, Pd, Cd) in the dried mushroom sample were determined using an Atomic Absorption Spectrophotometer (AAS) while Na and K were determined by flame emission photometry. Phosphorus was estimated by spectrophotometric method. The antioxidant activity of the crude mushroom extracts was evaluated by measuring their scavenging capacity on the stable radical, DPPH (2,2- Diphenyl-1-Picrylhydrazyl) using UV-Vi’s spectrophotometer at 517 nm. The mushroom was found to contain 64.53% total carbohydrates, 43.12% crude fibre, 11.67% crude proteins, 4.75% crude fat and 4.69% ash content on dry matter basis. The moisture content of the mushroom was found to be 80.33% of the fresh weight, which is typical of fresh foods and vegetables. A methanol extract of the mushroom exhibited antiradical activity against DPPH in a dose dependent manner with the highest radical scavenging capacity (40.84%) obtained at a concentration 500 µg/mL. For the mineral profile, the variations and concentrations of the essential and trace elements under study decreased in the order K˃Na˃Mg˃Ca˃Fe>P>Zn>Mn. The selected hazardous heavy metals Cd and Pb were not detected in the mushroom sample. Implications of the mineral concentrations on the nutritional value of the mushroom have been highlighted. In conclusion, the obtained results suggest that the mushroom, which has good amounts of the required proximate components, minerals and antiradical constituents, is a potentially healthy, safe and functional food.

Proximate and antinutritional analysis of locally produced condiment (Cwande) in Zuru Local Government Kebbi State, Nigeria

This study aimed to analyse the proximate and anti-nutritional components of Cwande in Zuru Local Government, Kebbi State. Five (5) samples in four (4) collection areas were collected and transported to Botany Laboratory Kebbi State University of Science and Technology, Aliero for analysis. The proximate and antinutrient parameters were analysed using the recommended AOAC (Association of Official Analytical Chemists) techniques. The results of the study showed that Cwande had high protein content (37.29±0.50%), followed by moisture (32.07±0.58%), fibre (14.80+3.06%), carbohydrate (7.62+0.81%), lipid (5.18+0.52%) and ash (3.02+1.76%). While the results of anti-nutritional composition showed that Cwande had high phytate composition (5.76 + 0.72) followed by saponins (5.51 + 0.61), cyanide (4.76 + 0.28) and oxalate (4.03 + 0.20). From these findings, it was discovered that Cwande condiments locally produced by Zuru people have good nutritional profile levels. However, the level of anti-nutrient contents in Cwande condiments is reduced. Further studies should be carry out to know the incidence of microbial flora of Cwande and also the toxins substances known to cause harmful effects to humans and animals.

Proximate analysis of some selected fish feeds marketed within Kano metropolis, Nigeria

Fish feeds (Fish bolsters) are produced in form of flakes, pellets, or tablets designed to contain vegetables, proteins, cereals, vitamins, and minerals fundamental for ideal development and wellbeing of fishes. However, the scientific evaluation of the feeds compositions as claimed by most manufacturers is lacking in many parts within Nigeria. Proximate composition analyses were carried out in some selected fish feeds marketed within the Kano metropolis following the method of the Association of Official Analytical Chemists. The result of the proximate investigation showed the following composition: 7.28-11.16% ash, 6.10-12.26% moisture, 11.13-14.29% lipid, 3.01-5.61 % fibre, 37.45-44.30% protein and 20.26-27.70% carbohydrate. There was no critical distinction (p>0.05) noticed among the values of all the proximate compositions of the fish feeds studied. However, a few values exceeded the permissible limit, whereas the majority fell within limits set by relevant regulatory agencies. Considering that most of the feeds were within the permissible limit of regulatory bodies, it could be deduced that the fish feeds are safe for fish consumption.

Development of analytical method for simultaneous detection of 1-[(2- chlorophenyl) methyllimino methyl] cyclopentanol hydroclorid (CCM) and 2- Hydroxy-2- (o-chloro phenyl) cyclohexanon (HCH), two precursors of ketamine, in wastewater by LC-MS/MS

Ketamin is a pharmaceutical compound that is abused as a narcotic drug, causing health problems for users. In controlling ketamine abuse, the detection of ketamine precursors can be a useful tool for tracing illegal ketamine production sites. In this study, an analytical method for determination of two ketamine precursors, 1-[(2-chlorophenyl) methyllimino methyl] cyclopentanol hydroclorid (CCM) and 2-Hydroxy-2- (o-chloro phenyl) cyclohexanon (HCH), in wastewater using solid phase extraction (SPE) and liquid chromatogrphy tandem mass spectrometry (LC-MS/MS) was developed and validated. An LC-MS/MS system employing a Zorbax C18 column (2.1 x 100 mm, 1.8 µm) and a mobile phase composing acetonitrile and water containing 0.1% (m/v) of formic acid in a gradient program at the flow rate of 0.3 mL/min and injection volume of 5 µL. The detection of analytes was done with electrospray ionization at positive mode (ESI+) employing multi reaction monitoring (MRM) at m/z of 238.5 and 225.5 for for CCM and HCH, respectively. The method was validated according to requirements of AOAC International and EC and was proved as reliable for intended use.  

Comparative Studies on the Proximate and Mineral Composition Of Green tea and Black tea from Nigeria

Green and Black tea are consumed by different shades of people in Nigeria to strengthen their immunity. This work was aimed at the analysis of the proximate and mineral compositions of Green and Black tea to determine the one that offers more nutrient values. Samples of the brands were collected from grocery shops. Analysis of the proximate composition of the tea samples was done following the standard procedures of Association of Official Analytical Chemists, while the mineral composition was determined using atomic absorption spectrophotometer . All the chemicals used in this work were of analytical grades. Screening for proximate and mineral composition of the processed tea samples indicated the presence of the following minerals in mg/g -Manganese, Copper, Zinc, Iron, Sodium, Magnesium. Calcium and Lead were not detected in the two tea samples, while Zinc was not in Black tea, and Potassium in Green tea. Iron, Zinc, Sodium and Manganese had the highest value in Green tea than in Black, whereas Potasium and Cupper had the highest value in Black tea than in Green tea. For the proximate in % -Moisture , Ash, Protein, Crude Fats, Fiber, Carbohydrate were present. Moisture, Fibre, Ash and Fats and oil had the highest value in Green tea than in Black tea, whereas Protein and Carbohydrate had the highest values in Black tea than in Green tea. The results, generally, offer greater opportunity for consumers to choose which tea type could be more beneficial for improving immunity.

UFLC-FD Metodu ile Kayısı Çekirdeğinde Aflatoksin Tayini ve Laboratuvar İçi Metot Validasyonu

Mevcut çalışmada kayısı çekirdeği ve yer fıstığı örneklerinde aflatoksin varlığı incelenmiş ve uygulanan metodun laboratuvar içi validasyonu iki analist tarafından gerçekleştirilmiştir. Kayısı çekirdeği örnekleri Malatya ilinde kayısı ticareti yapılan Şire Pazarı’ndan, yer fıstığı örnekleri ise yine aynı ildeki bazı kuruyemişçilerden temin edilmiştir. Association of Official Analytical Chemists (AOAC)’nin 991.31 nolu metodu ile floresans dedektörlü ultra hızlı sıvı kromatografisi (UFLC-FD) sisteminde analizler gerçekleştirilmiştir. Kayısı çekirdeği örneklerinden bir tanesinde aflatoksin B1 1.250±0.081 μg kg-1 ve toplam aflatoksin 1.401±0.097 μg kg-1 olarak ölçülürken diğer kayısı çekirdeği ve yer fıstığı örneklerinde aflatoksin tespit edilememiştir. Analitik çalışmalar sonucunda aflatoksin standardının UFLC-FD sisteminde lineer ölçüm aralığı 0.08 – 2.5 μg kg-1, aflatoksin B1 ve toplam aflatoksin için LOD değerleri sırasıyla 0.036 ve 00.120 μg kg-1, LOQ değerleri ise 0.084 ve 0.280 μg kg-1 olarak belirlenmiştir.

Lipid content and fatty acid profile of commonly consumed freshwater and marine fish of Bangladesh

The objectives of this research were to determine total lipid content and corresponding fatty acid profiles in freshwater (n=10) and marine fish (n=11) samples commonly consumed in Bangladesh. Lipid was extracted by Solid Phase Dispersion method. Saponification and esterification were carried out by the association of official analytical chemists (AOAC) reference procedure with some simple modifications. The fatty acids were analyzed as their methyl ester by gas chromatography equipped with flame ionization detector (GC-FID) by comparing the retention time of 13 standard methyl ester of fatty acids. Total lipid content was 0.97-8.05% and 0.97-4.33% in freshwater and marine fish, respectively. Unsaturated fatty acid in freshwater fish was found in highest amount than saturated fatty acid. Among unsaturated fatty acids, palmitoleic acid was found in highest concentration and ranged from 46.80-26.02%. Palmitic acid was found in highest amount among saturated fatty acids and ranged from 3.96-13.91%. Among the marine fishes unsaturated fatty acids (MUFAs and PUFAs) i.e; palmitoleic acid (26.21-41.61%), oleic acid (2.35-29.63%) and linoleic acid (1.40-14.45%) were predominant. Among the saturated fatty acids myristic acid (0.97-9.08%), palmitic acid (1.61-11.35%) and stearic acid (1.03-21.53%) were found to be predominant.

LC-MS/MS를 이용한 건강기능식품 중 키토산 분석법 연구

The Ministry of Food and Drug Safety is amending its test methods for dietary supplements (functional health food) to establish regulatory standards and specifications in South Korea. In this study, we develop analytical test methods to improve the sensitivity and selectivity of the chitosan test method. We develop liquid chromatographic-tandem mass spectrometry for a chitosan analysis using acid hydrolysis to glucosamine. This method can be used to characterize and quantify dietary supplement formulations containing chitosan. The procedure was validated in the 78 ~ 2,500 ng/mL range, and standard calibration curves presented linearity with the coefficient of determination (r²) > 0.999. The limits of detection and quantitation were 51 ng/mL and 154 ng/mL, respectively. The recovery results ranged between 94.8 ~ 102.9% at three different concentration levels with relative standard deviations less than 3.1%, and precision (0.8 ~ 2.5%) was obtained. These are in accordance with the established validation criteria (Association of Official Analytical Chemists). Subsequently, our research provides scientific evidence for amending the chitosan test method for the Health Functional Food Codes.