Methods for the determination of lactose in milk and milk products

Laktoza je sladkor prisoten v mleku, ki ga 75 % ljudi težje prebavlja. Zaradi razširjenosti težav se povečuje proizvodnja mleka brez laktoze. Mleko in mlečne izdelke se analizira z različnimi analiznimi metodami. V besedilu so zajete glavne metode za določanje laktoze v mleku in mlečnih izdelkih, ki se uporabljajo na Inštitutu za mlekarstvo in probiotike (v nadaljevanju IML-PRO). Predstavljene so tudi nekatere druge uspešne metode. Najbolj razširjena je uporaba metode MID-IR, ki služi kot glavna rutinska metoda za analizo glavnih komponent mleka. Predstavljena je metoda diferencialne pH-metrije, ki se na IML-PRO uporablja pri izvedbi laboratorijskih poskusov. Najbolj občutljiva metoda, ki jo uporabljajo na IML-PRO, je metoda HPLC, ki služi kot referenčna metoda za preostale metode. Uporabljajo se tudi encimske metode, ki dajejo zadovoljive rezultate. Metoda HPAEC PAD se je na podlagi študij izkazala za najobčutljivejšo metodo z najnižjo mejo zaznavnosti. Metoda je referenčna in zahtevnejša za uporabo, prav tako kot HPLC je metoda časovno zamudnejša in cenovno dražja. Vsaka opisana metoda ima določene prednosti in slabosti. Razvoj znanosti se vse bolj nagiba k iskanju še hitrejših in učinkovitejših metod. Razvijajo se biosenzorji z različnimi elektrodami, ki zagotavljajo hitre in primerljive rezultate s preostalimi metodami.Lactose is a milk sugar that is difficult to digest for 75% of human population. Lactose-free milk production is increasing due to the prevalence of the problem. Milk and dairy products are analyzed by various analytical methods. The text covers the main methods for the determination of lactose in milk and dairy products used at the Institute of Dairy Science and Probiotics (hereinafter IML-PRO). Some other successful methods are also presented. The most widespread method, used at IML-PRO, is the MID-IR method, which serves as the main routine method for the analysis of the main components of milk. There is also a differential pH metric method presented which is used in laboratory experiments at IML-PRO. The most sensitive method, used at IML-PRO, is the HPLC method, which serves as a reference method for other methods. Enzymatic methods are also used to give satisfactory results. Based on studies, the HPAEC PAD method has proven to be the most sensitive method so far, with the lowest detection limit. The method is a reference method and quite demanding to use, just like HPLC, the method is more time consuming and expensive. Each method described has certain advantages and disadvantages. The development of science is increasingly leaning towards finding even faster and more efficient methods. Biosensors with different electrodes are being developed that provide fast and comparable results with other methods