Modification of AOAC Official MethodSM 998.12 to Add Filtration and/or Centrifugation: Interlaboratory Comparison Exercise

Rogers, Karyne M.; Cook, Jo Marie; Krueger, Dana A; Beckmann, Klaus

doi:10.5740/jaoacint.12-386

Cited by 12 publications

(13 citation statements)

References 4 publications

(3 reference statements)

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“…To date, the factors underpinning this phenomenon are largely unexplained; however, work done by Rogers et al . (, , 2014a,b) has clearly shown that in many cases the current official methods (AOAC, ) are not sufficiently sensitive for C 4 level detection in some honeys and have called for a revision to the accepted protocols.…”

Section: Discussionmentioning

confidence: 99%

“…These non‐protein components may have isotope values which are considerably different from those of the pure protein, and can shift isotopic signatures away from true protein values (Rogers et al . , ). Briefly, 4 ml of distilled H 2 O was added to 10–12 g honey.…”

Section: Methodsmentioning

confidence: 99%

“…Purified honey protein was extracted from whole honey using a modified ver. of the repetitive wash method as described by Rogers et al (2010Rogers et al ( , 2013, which employs a centrifugal and filtration step prior to standard AOAC protocols (AOAC 1999). This is to prevent the inclusion of pollen and other insoluble components with the flocculated protein.…”

Section: Stable Isotope Analysismentioning

confidence: 99%

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Antimicrobial properties and isotope investigations of South African honey

et al. 2014

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Aims The therapeutic potential of honey for the treatment of wound infections is well documented. However, South African (SA) honey has been poorly explored as an antimicrobial agent and given the well‐established antimicrobial properties of the indigenous plant species from SA, there is the potential that honey from this geographical region may exhibit noteworthy anti‐infective properties. In this study, the antimicrobial properties of 42 SA honey samples were determined. Methods and Results The minimum inhibitory concentration (MIC) agar dilution method was used to determine antimicrobial activity. The MICs of the honeys ranged from 6·25 to 50·00%. Samples 4‐(CITYMIX/WC), 12‐(BUSHVELD/KZN), 15‐(ONION/WC), 16‐(FYNBOS/WC), 17‐(AKMS/FS), 19‐(CITYMIX/FS), 41‐(INDIGENOUS/WC) and 52‐(SURBURBANGARDEN/WC) displayed broad‐spectrum antimicrobial activity. The physicochemical properties including pH, water content and stable isotope analysis (SIA) was analysed. The pH of the honeys ranged between 3·89 and 5·09. The SIA revealed strong overall trends between protein concentration and MIC suggesting close links with antimicrobial activity. Conclusion A number of SA honey samples tested have potential as an effective antimicrobial agent in wound healing. Significance and Impact of the Study The future of South Africa's market for medical grade and therapeutic honeys looks promising as the antimicrobial properties of the honeys have some superior activity.

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Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Stable Isotope Analysismentioning

confidence: 99%

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Antimicrobial properties and isotope investigations of South African honey

et al. 2014

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“…In doping control, it is used to confirm the endogenous steroid abuse by distinguishing the differences in the carbon isotope ratios of 13 C/ 12 C (or expressed as the carbon isotopic composition, δ 13 C) between the chemically synthesized and endogenously produced steroid hormones . Another important application of IRMS is the identification of food authenticity . Elemental analyzer coupled with IRMS was used to determine the presence of C4 (corn syrup or cane sugars) in honey by comparing the carbon isotopic value of whole honey with its internal protein .…”

Section: Introductionmentioning

confidence: 99%

“…Another important application of IRMS is the identification of food authenticity . Elemental analyzer coupled with IRMS was used to determine the presence of C4 (corn syrup or cane sugars) in honey by comparing the carbon isotopic value of whole honey with its internal protein . Furthermore, IRMS has been used for the discrimination of wild and farmed animal products.…”

Section: Introductionmentioning

confidence: 99%

Discrimination of wild and domestic deer musk using isotope ratio mass spectrometry

Wang

et al. 2018

J Mass Spectrom

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Musk is the dried secretion of the musk pod (sac) of adult male musk deer, and has been used as perfume and traditional medicine for thousands of years. Steroid was regarded as 1 of the most important active compounds in musk. In order to protect the wild musk deer, musk deer farming has been carried out in China, India, and Nepal. However, it is hard to differentiate the 2 origins of musk by morphological identification. No other method has been reported so far for the discrimination of wild and domestic deer musk. The establishment of a reliable discrimination method has become an urgent work. In the present study, 6 batches of wild deer musk and 14 batches of domestic deer musk were collected. Analysis of steroid components in musk was carried out with GC-MS/MS. Androgen, progestin, estrogen, and sterol were detected in those samples. Large diversity was observed in the concentrations of steroids in musk. No obvious difference could be observed in steroid concentrations between wild and domestic deer musk by principal component analysis and cluster analysis. Furthermore, the δ C values of steroids were determined by gas chromatography/combustion coupled with isotopic ratio mass spectrometry. There were significant differences (P < .01) in steroid δ C values between wild origin musk and domesticated origin musk. Isotopic ratio mass spectrometry can be used to discriminate wild and domestic deer musk.

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The Validity of Protein in Australian Honey as an Internal Standard for C4 Sugar Adulteration

et al. 2021

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Recent media reports claimed that a large proportion of honey sold in Australian supermarkets was adulterated, although no specific details of the nature of the adulteration were made public.To investigate the basis of these claims, the current study was conducted with samples of Australian honey obtained from supermarkets or direct from beekeepers/small scale producers.Without evidence to the contrary, it was assumed that the beekeeper honey would be unadulterated. Analysis of these samples using the official AOAC method (998.12) found that a proportion of both supermarket and beekeeper honeys had apparent C4 sugar contents greater than 7% and this proportion was similar to the failure rates reported by popular media. The AOAC test measures the difference in carbon isotopic composition between the honey (mostly sugar) and protein precipitated from the honey and relies on the assumption that nectar (the source of sugar) comes from the same plant species as pollen (the source of protein). Initial results found that most Australian honey failed the AOAC test because the protein was depleted in 13 C with respect to the sugar although the sugar was in the normal range (δ 13 C more negative than -24‰). A series of experiments investigated the nature of the precipitate obtained from Australian honey and found the weight of precipitate was greater than the amount of protein measured in the honey and the precipitate contained non-protein material. Based on these findings a modification to the AOAC method is proposed whereby samples, after addition of sodium tungstate and acid, are left unheated for 48 hours for a floc to form. This procedure produced a precipitate that was mostly comprised of protein. It is also recommended that the acceptance criteria for Australian honey is increased from 1‰ to 2‰ difference between the carbon isotopic composition of the honey and the precipitate. Using the modified method and acceptance criteria the failure rate for Australian honey was no more than 8%, compared to 37% using the official method.

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Modification of AOAC Official MethodSM 998.12 to Add Filtration and/or Centrifugation: Interlaboratory Comparison Exercise

Cited by 12 publications

References 4 publications

Antimicrobial properties and isotope investigations of South African honey

Antimicrobial properties and isotope investigations of South African honey

Discrimination of wild and domestic deer musk using isotope ratio mass spectrometry

The Validity of Protein in Australian Honey as an Internal Standard for C4 Sugar Adulteration

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