Quality of UHT goat's milk in Poland evaluated by real-time PCR

Animal Species Authentication in Dairy Products

Milk is one of the most important nutritious foods, widely consumed worldwide, either in its natural form or via dairy products. Currently, several economic, health and ethical issues emphasize the need for a more frequent and rigorous quality control of dairy products and the importance of detecting adulterations in these products. For this reason, several conventional and advanced techniques have been proposed, aiming at detecting and quantifying eventual adulterations, preferentially in a rapid, cost-effective, easy to implement, sensitive and specific way. They have relied mostly on electrophoretic, chromatographic and immunoenzymatic techniques. More recently, mass spectrometry, spectroscopic methods (near infrared (NIR), mid infrared (MIR), nuclear magnetic resonance (NMR) and front face fluorescence coupled to chemometrics), DNA analysis (real-time PCR, high-resolution melting analysis, next generation sequencing and droplet digital PCR) and biosensors have been advanced as innovative tools for dairy product authentication. Milk substitution from high-valued species with lower-cost bovine milk is one of the most frequent adulteration practices. Therefore, this review intends to describe the most relevant developments regarding the current and advanced analytical methodologies applied to species authentication of milk and dairy products.

Real Time-PCR coupled with melt curve analysis for detecting the authenticity of camel milk

The study evaluated the use of Real Time-Polymerase Chain Reaction (RT- PCR) to detect the adulteration of camel milk with goat, cow milk. DNA was isolated from camel milk, camel milk powder, camel milk soap, cow milk, and goat milk using DNA extraction kit. RT- PCR amplified a single piece of DNA into millions of copies. The camel specific primers were designed using the primer- 3 online software and quantification of the isolated DNA was carried out by RT- PCR system through DNA standard curves and cycle threshold (Ct) values. The detection limit of DNA template was in the range of 0.001-0.002%. The reaction mixture (20μL) contained 10 μL SYBR Green master mix, 0.3 μL of 10 μM of each primer and 5 μL DNA. Thermal cycling consisted of an initial denaturation at 95 °C for 1 min, followed by 40 cycles for 15 s at 95 °C and 60 °C for 30 s. The primer pairs used were confirmed for their PCR efficiency, and specific products were evaluated by melt curve analysis. Results indicated positive amplification for the camel milk, camel milk powder, and camel milk soap but negative amplification for cow and goat milk. In conclusion, the RT- PCR based identification is a low cost and appropriate method for camel milk and its products. Although, the yield of DNA from camel milk soap after isolation is low but the isolated DNA segment was easily identified.

Probiotics in Goat Milk Products: Delivery Capacity and Ability to Improve Sensory Attributes

Dairy foods, particularly those of bovine origin, are the predominant vehicles for delivery of probiotic bacteria. Caprine (goat) milk also possesses potential for successful delivery of probiotics, and despite its less appealing flavor in some products, the use of goat milk as a probiotic carrier has rapidly increased over the last decade. This review reports on the diversity, applicability, and potential of using probiotics to enhance the sensory properties of goat milk and goat milk-based products. A brief conceptual introduction to probiotic microorganisms is followed by an account of the unique physicochemical, nutritive, and beneficial aspects of goat milk, emphasizing its advantages as a probiotic carrier. The sensory properties of probiotic-enriched goat milk products are also discussed. The maintenance of probiotic viability and desirable physicochemical characteristics in goat milk products over shelf life is possible. However, the unpleasant sensory features of some goat milk products remain a major disadvantage that hinder its wider utilization. Nevertheless, certain measures such as fortification with selected probiotic strains, inclusion of fruit pulps and popular flavor compounds, and production of commonly consumed tailor-made goat milk-based products have potential to overcome this limitation. In particular, certain probiotic bacteria release volatile compounds as a result of their metabolism, which are known to play a major role in the aroma profile and sensory aspects of the final products.

Detection of Adulterants and Contaminants in Liquid Foods-A Review

Milk and fruit juices have paramount importance in human diet. Increasing demand of these liquid foods has made them vulnerable to economic adulteration during processing and in supply chain. Adulterants are difficult to detect by consumers and thus necessitating the requirement of rapid, accurate and sensitive detection. The potential adulterants in milk and fruit juices and their limits set by different regulatory bodies have been briefly described in this review. Potential advantages and limitations of various techniques such as physicochemical methods, chromatography, immunoassays, molecular, electrical, spectroscopy with chemometrics, electronic nose, and biosensors have been described. Spectroscopy in combination with chemometrics has shown potential for rapid, precise, and sensitive detection of potential adulterants in these liquid foods.