ABSTRACT
RESEARCH BACKGROUND: The presence of insect fragments is one of the major constrains in stored food commodities and it causes considerable loss in the quality of the produce. The management of the pest is viewed as a huge challenge in foodprocessingindustry. Conventionally, the detection of Tribolium castenaum in the food processing industry is carried out by acid hydrolysis and staining methods that are time consuming and lack precision. EXPERIMENTAL APPROACH: Considering the importance of a quick and effective method, a quantitative polymerase chain reaction (qPCR)-based approach was developed and elucidated in this study. The mitochondrial cytochrome oxidase I (mtCOI) gene was identified as a target due to its abundance in the pest. Specific primers were designed against the target gene by Primer Premier software and amplified in a qPCR. RESULTS AND CONCLUSIONS: This method is capable of detecting all the ontogenic stages of T. castaneum in stored wheat flour. Earlier experiments had demonstrated that about 20 µg of DNA can be obtained from 2.2 mg of insects. To quantify the infestation levels, the cycle threshold (Ct) values obtained from known samples were subjected to regression analysis and expressed as adult equivalents. In the unknown samples, the infestation was calculated as 1.74 and 0.046 adult insects in 5 g of wheat flour. The maximum permissible limit of insect fragments in flour is 75 insect fragments or approx. 3 adults per 50 g of flour as per the US Food and Drug Administration (FDA). Hence, by adopting this new method, it is possible for the warehouse operators to arrive at a decision to proceed with efficient management practices where wheat flour is stored. Also, this method can be ratified by government agencies associated with international business to ascertain whether the wheat flour meets the standards set by the respective country before subjecting to foreign trade. NOVELTY AND SCIENTIFIC CONTRIBUTION: This study is the first of its kind in the detection and quantification of T. castaneum in milled products. So far, only conventional methods have been employed to assess the presence of the pests and manual counting of fragments are practiced to quantify the infestation levels. The developed qPCR method is faster, reliable and can be employed in milling industries, bakery industries, food processing plants and foreign trade units for critical detection and quantification of T. castaneum pest infestation.
ABSTRACT
This study evaluated the influence of 10% vinegar and solar drying using two solar dryers and open-sun drying on the microbiological quality of ginger (Zingiber officinale Roscoe) rhizome. The rhizomes were analyzed for bacterial, mold, and Salmonella populations in the raw state, which were water-washed and soaked in 10% vinegar, and in dried form. The fungal population was isolated and identified. Fresh and dried ginger rhizome contained both bacterial and fungal population in the range of 3.0 x 102 ± 1.14 x 102 to 2,180 x 109 ± 70.7 x 109 CFU/g. The stainless steel solar dryer had fewer fungal loads among the drying methods. Aspergillus and Penicillium species of mycotoxin-producing potential were identified. The 10% vinegar as pretreatment showed no significant difference (p ≤ .05) in the bacterial population reduction but in the fungal population reduction. Growth of fungi in fresh and dried ginger extracts was lower compared with growth in Potato Dextrose Broth.
ABSTRACT
Potassium bromate, is an oxidizing agent and one of the best and cheapest dough improvers in the baking industry. Due to its positive effects it plays a major role in the bread-making industry. Potassium bromate has significant effect on food biomolecules, such as starch and protein, as it affects the extent of gelatinization, viscosity, swelling characteristics as well as gluten proteins; it removes the sulfhydryl group and leads to the formation of disulfide linkages and thus improves the bread properties. However, there are many reports elucidating its negative impact on human health. It is deemed as a potential human carcinogen by IARC and classified under class 2B. Due to this, countries across world have either partially or completely banned it. Numerous techniques have evolved to determine the concentration of potassium bromate in bread. This review explains in detail, the effects of potassium bromate on biomolecules, human health, environment and various methods of analysis.
