Detection of species adulteration in meat products and Mozzarella-type cheeses using duplex PCR of mitochondrial cyt b gene: A food safety concern in Bangladesh.

Food origin authentication is imperative for consumer protection. This study explored meat and milk species identification as a pioneering country-specific report on mislabeling prevalence among processed meat and milk products in Bangladesh. Meat products (64; sausages, burger patty, meatball, kabab) labeled as chicken or beef and Mozzarella-type cheeses (25), made in Bangladesh and of overseas origins, were analyzed for species detection. Two duplex PCR (cattle-buffalo and chicken-pig) were applied with species-specific mitochondrial Cyt b gene primers and determine to be accurate for species identification in meat and milk. Bangladeshi origin beef-labeled products were found to be mixed with buffalo (n = 2) and chicken (n = 5) suggesting up to one third of products might be mislabeled. Such mislabeling would allow these 'beef' products to charge a higher price compared with chicken products that command a lower price. Imported meat products were also found mislabeled with buffalo and chicken. Cheese samples, declared as bovine, were found to contain buffalo DNA, and no cattle or buffalo DNA was found in six imported cheese samples. All the meat and cheese products were Halal, as none contained pig DNA. This pilot study shows the majority of products were labelled correctly, but large proportions were not and strict monitoring is recommended to ensure food safety and address consumer preferences, especially religious concerns.

Identification of a novel protein, CRR7, required for the stabilization of the chloroplast NAD(P)H dehydrogenase complex in Arabidopsis.

An Arabidopsis thaliana mutant, crr7 (chlororespiratory reduction), was isolated using chlorophyll fluorescence imaging to detect reduced activity in NAD(P)H dehydrogenase (NDH). The chloroplast NDH complex is considered to have originated from cyanobacteria in which the NDH complex is involved in respiration, photosystem I (PSI) cyclic electron transport and CO2 uptake. In higher plants the NDH complex functions in PSI cyclic electron transport within the chloroplast. Despite exhaustive biochemical approaches, the entire subunit composition of the NDH complex is unclear in both cyanobacteria and chloroplasts. In crr7 accumulation of the NDH complex was specifically impaired. In vivo analysis of electron transport supported the specific loss of the NDH complex in crr7. CRR7 (At5g39210) encodes a protein of 156 amino acids, including a putative plastid target signal, and does not contain any known motifs. In contrast to CRR2 and CRR4, involved in the expression of chloroplast ndh genes, CRR7 is conserved in cyanobacterial genomes. Although CRR7 did not contain any transmembrane domains, it localized to the membrane fraction of the chloroplast. CRR7 was unstable in the crr2-2 mutant background, in which the expression of ndhB was impaired. These results strongly suggest that CRR7 is a novel subunit of the chloroplast NDH complex.