Nils Th. Grabowski

Dr. Nils Th. Grabowski

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Research Focus & Metrics

Academic Career Length

22Years (2005-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 February 2017 in International Journal of Food Microbiology
Verified
Journal Article
Closed access
NGNils Th. Grabowski
Nils Th. Grabowski
KGKlein Günter
Klein Günter

21 March 2005 in Journal of Dairy Research
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Journal Article
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BBBaljinder K Bansal
Baljinder K Bansal
JHJoern Hamann
Joern Hamann
NGNils Th. Grabowski
Nils Th. Grabowski
KSKrishan B Singh
Krishan B Singh
Seven variables – electrical conductivity (EC), somatic cell count (SCC), N-acetyl-β-D-glucosaminidase (NAGase), lactose, protein, fat and pH – were compared in four quarter milk fractions (MF1: strict foremilk; MF2: first 12–15 ml foremilk; MF3: subsequent 40–45 ml milk; MF4: strippings) and in one cow composite milk sample (CC) per cow. The study used 142 quarters from 37 lactating cows of the German Black Pied breed. To rule out any possible effect due to management, animal physiology and analytical procedures, the collection and processing of milk samples from each cow was repeated for three consecutive days, and the means of 3-d values were used. All variables were affected significantly by milk fraction and udder health. Compared with foremilk, EC, lactose and protein levels in strippings decreased, while SCC, NAGase and fat increased. The pH of foremilk and strippings did not differ significantly in healthy or in mastitic quarters. The difference between MF1 and MF2 was significant for EC in mastitic quarters, and for SCC in healthy quarters only. In general, mastitis resulted in a significant increase in EC, SCC, NAGase and protein but in a decrease in lactose and fat contents of milk in one or more of the milk fractions studied. Comparison of cow composite milk samples from healthy and mastitic cows revealed the significance (P<0·01) of udder health for EC, SCC and lactose. Of the different parameters that can distinguish between healthy and mastitic quarters or cows, EC could be used to classify 76% of quarters and 73% of cows correctly, while the lactose content permitted correct identification of 81% of quarters and 76% of cows. NAGase and pH could be used to determine the status of 73% and 61% of quarters, respectively. In general, the correlation observed in strippings was higher than in foremilk for almost all the variables studied. Surprisingly, EC, SCC, NAGase and lactose in milk from healthy quarters of mastitic cows (with at least one mastitic quarter) differed significantly (P<0·05) from those from healthy quarters of cows with all four healthy quarters, indicating an inconsistent effect of mastitic quarters on neighbouring healthy quarters (quarter interdependence).

9 July 2016 in Food Science and Technology International
Verified
Journal Article
Open access
NGNils Th. Grabowski
Nils Th. Grabowski
GKGünter Klein
Günter Klein
To increase the shelf life of edible insects, modern techniques (e.g. freeze-drying) add to the traditional methods (degutting, boiling, sun-drying or roasting). However, microorganisms become inactivated rather than being killed, and when rehydrated, many return to vegetative stadia. Crickets (Gryllus bimaculatus) and superworms (Zophobas atratus) were submitted to four different drying techniques (T1 = 10′ cooking, 24 h drying at 60℃; T2 = 10′ cooking, 24 h drying at 80℃; T3 = 30′ cooking, 12 h drying at 80℃, and 12 h drying at 100℃; T4 = boiling T3-treated insects after five days) and analysed for total bacteria counts, Enterobacteriaceae, staphylococci, bacilli, yeasts and moulds counts, E. coli, salmonellae, and Listeria monocytogenes (the latter three being negative throughout). The microbial counts varied strongly displaying species- and treatment-specific patterns. T3 was the most effective of the drying treatments tested to decrease all counts but bacilli, for which T2 was more efficient. Still, total bacteria counts remained high (G. bimaculatus > Z. atratus). Other opportunistically pathogenic microorganisms (Bacillus thuringiensis, B. licheniformis, B. pumilis, Pseudomonas aeruginosa, and Cryptococcus neoformans) were also encountered. The tyndallisation-like T4 reduced all counts to below detection limit, but nutrients leakage should be considered regarding food quality. In conclusion, species-specific drying procedures should be devised to ensure food safety.

25 June 2014 in PLOS ONE
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AAAmir Abdulmawjood
Amir Abdulmawjood
NGNils Th. Grabowski
Nils Th. Grabowski
SFSvenja Fohler
Svenja Fohler
SKSophie Kittler
Sophie Kittler
HNHelga Nagengast
Helga Nagengast
GKGuenter Klein
Guenter Klein
Animal species identification is one of the primary duties of official food control. Since ostrich meat is difficult to be differentiated macroscopically from beef, therefore new analytical methods are needed. To enforce labeling regulations for the authentication of ostrich meat, it might be of importance to develop and evaluate a rapid and reliable assay. In the present study, a loop-mediated isothermal amplification (LAMP) assay based on the cytochrome b gene of the mitochondrial DNA of the species Struthio camelus was developed. The LAMP assay was used in combination with a real-time fluorometer. The developed system allowed the detection of 0.01% ostrich meat products. In parallel, a direct swab method without nucleic acid extraction using the HYPLEX LPTV buffer was also evaluated. This rapid processing method allowed detection of ostrich meat without major incubation steps. In summary, the LAMP assay had excellent sensitivity and specificity for detecting ostrich meat and could provide a sampling-to-result identification-time of 15 to 20 minutes.

16 April 2020 in Foods
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Journal Article
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NGNils Th. Grabowski
Nils Th. Grabowski
STSéverin Tchibozo
Séverin Tchibozo
AAAmir Abdulmawjood
Amir Abdulmawjood
FAFatma Acheuk
Fatma Acheuk
MGMeriem Msaad Guerfali
Meriem Msaad Guerfali
MPMadeleine Plötz
Madeleine Plötz
Entomophagy is an ancient and actually African tradition that has been receiving renewed attention since edible insects have been identified as one of the solutions to improve global nutrition. As any other foodstuff, insects should be regulated by the government to ensure product quality and consumer safety. The goal of the present paper was to assess the current legal status of edible insects in Africa. For that, corresponding authorities were contacted along with an extensive online search, relying mostly on the FAOLEX database. Except for Botswana, insects are not mentioned in national regulations, although the definitions for “foodstuff” allow their inclusion, i.e., general food law can also apply to insects. Contacted authorities tolerated entomophagy, even though no legal base existed. However, insects typically appear in laws pertaining the use of natural resources, making a permit necessary (in most cases). Pest management regulation can also refer to edible species, e.g., locusts or weevils. Farming is an option that should be assessed carefully. All this creates a complex, nation-specific situation regarding which insect may be used legally to what purpose. Recommendations for elements in future insect-related regulations from the food hygiene point of view are provided.

1 May 2011 in Veterinary Immunology and Immunopathology
Verified
Journal Article
Closed access
JMJalil Mehrzad
Jalil Mehrzad
GKG. Klein
G. Klein
JKJ. Kamphues
J. Kamphues
PWP. Wolf
P. Wolf
NGNils Th. Grabowski
Nils Th. Grabowski
HSH.J. Schuberth
H.J. Schuberth