Development of a HPLC Fluorescence Method for Determining Efficacy of Milk Pasteurization

  • PDF / 347,071 Bytes
  • 8 Pages / 595.276 x 790.866 pts Page_size
  • 104 Downloads / 186 Views

DOWNLOAD

REPORT


Development of a HPLC Fluorescence Method for Determining Efficacy of Milk Pasteurization Meena kumari R. 1 & Vijay J. Jadhav 2 & Prarabdh C. Badgujar 1 Received: 16 April 2020 / Accepted: 22 September 2020 # Springer Science+Business Media, LLC, part of Springer Nature 2020

Abstract Alkaline phosphatase (ALP) is an active enzyme present in the raw milk. Due to its unique heat-sensitive properties, it is employed as an indicator to evaluate efficiency of the pasteurization treatment. In the present study, a method comprising of HPLC with fluorescence detector was developed for the quantification of ALP enzyme activity in the pasteurized milk. The method is based on the detection and quantification of 4-methylumbelliferone (4MU) liberated by the action of phosphatase enzyme (in the milk) on the substrate 4-methylumbelliferyl phosphate (4MUP). Extraction and purification of 4MU was done by clarification, centrifugation, and solid phase extraction processes. The target compound separation was achieved with the help of reversed-phase C18 column using gradient elution consisting of a binary mobile phase: HPLC grade water and methanol. The fluorescence detection was accomplished with the excitation and emission wavelengths being 365 and 460 nm, respectively. The method validation experiments clearly showed high specificity, good linearity (r2 > 0.9901), low limits of detection (0.349 mg/L) and quantification (LOQ, 0.432 mg/L), accuracy (> 100%), and precision (%RSD < 4.7652). Comparative evaluation against Lovibond comparator method revealed that the HPLC method has an advantage of detecting very low levels of ALP activity and raw milk contamination. This is the first report of detecting such low levels of ALP in the milk by HPLC-fluorescence detector technique. This new chromatographic method can be considered as a substitute to the existing standard methods that employ fluorometric technique for detecting ALP activity in the pasteurized milk. Our method could certainly enhance the quality assurance standards currently employed in the dairy industry. Keywords Milk . Alkaline phosphatase . 4-Methylumbelliferone . 4-Methylumbelliferyl phosphate . HPLC-fluorescence detection

Introduction Milk is a highly nutritious dietary constituent of humans for all age groups. Inadequate heat treatment of milk can pose a risk of exposing consumers to the surviving milk pathogens, while excessive heat treatment adversely affects nutritive value of the milk. Pasteurization process uses a well-defined and adequately optimized time-temperature combinations to destroy pathogens present in the milk. However, it becomes important

* Prarabdh C. Badgujar [email protected]; [email protected] 1

Department of Food Science and Technology, National Institute of Food Technology Entrepreneurship and Management, Kundli, Sonipat, Haryana, India

2

Department of Veterinary Public Health and Epidemiology, Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar, Haryana, India

to evaluate the efficacy of heat treatm