Kisla sirotka: od odpadka do dragocene surovine za živila in prehranska dopolnila

Tragin, Luka (avtor), Bogovič Matijašić, Bojana (mentor)

Sirotka je rumeno zelena tekočina, ki je stranski produkt mlekarske industrije. Poznamo sladko sirotko, ki nastane pri proizvodnji sira, ter kislo sirotko, ki je največ nastane pri proizvodnji grškega tipa jogurta in skute. Slednja vsebuje manjši delež beljakovin in laktoze ter ima nizek pH, zato jo v veliki meri uporabljajo za gnojenje in hrano za živali ali pa konča kot odpadek. To pa povzroča proizvajalcem dodatne stroške ali pa vodi v onesnaževanje okolja, kadar je neprimerno zavržena. Zaradi višje vsebnosti mineralov in kislosti ni priporočljivo dodajanje h krmi v preveliki meri. Zaradi mineralov ter mlečne kisline jo je tudi težje predelati, razen tega pa je proces finančno zahtevnejši. Razvoj tehnologije je omogočil nove separacijske tehnike, ki so uporabne pri predelavi kisle sirotke, ki sicer vsebuje veliko dragocenih in biološko aktivnih sestavin. Prvi korak pri predelavi je običajno nevtralizacija oziroma odstranitev mlečne kisline. S tem dobimo surovino, ki jo lahko naprej uporabimo podobno kot sladko sirotko. Najuporabnejše metode temeljijo na membranskih tehnikah ter kromatografiji. Z novimi tehnikami je mogoče pridobiti posamezne sestavine, ki so uporabne v mlekarski, mesni in pekarski industriji ali pa v proizvodnji prehranskih dopolnil. Z vidika mlekarn je potrebno najprej ovrednotiti procese predelave z ekonomskega vidika in najti pravo razmerje med ekonomsko računico in izkoristkom.

• Jezik: Slovenski jezik
• Ključne besede: kisla sirotka, kemijska sestava, minerali, mlečna kislina, beljakovine, funkcionalna živila, predelava sirotke, kromatografija, membranske tehnike, stranski produkt
• Vrsta gradiva: Diplomsko delo/naloga
• Tipologija: 2.11 - Diplomsko delo
• Organizacija: BF - Biotehniška fakulteta
• Založnik: [L. Tragin]
• Leto izida: 2018
• PID: 20.500.12556/RUL-103167
• UDK: 637.344:641.1
• COBISS.SI-ID: 4954744
• Datum objave v RUL: 14.09.2018

Sekundarni jezik

• Jezik: Angleški jezik
• Naslov: Acid whey: from waste to a valuable raw material for foods and food supplements

Izvleček

Whey is a yellow-green liquid which is a side product of dairy industry. The sweet whey is a side product of cheese production and the acid whey is a side product in production of Greek type yoghurt- quark and similar products. The latter has less protein and lactose and lower pH, for this reason it is often used as a fertilizer and feed for animals or treated as waste product. This contributes to higher costs or leads even to environmental pollution, when treated inappropriate. Due to higher mineral content and acidity it is not recommended to be included into animal nutrition in large quantities in fodder. Mineral content and lactic acid presence is the reason why it is harder to process it and it also requires more finances. Advances in technology and new knowledge lead to new separation techniques which have a great effect on processing of acid whey which still contains valuable and biologically active components. The first step in this process is the neutralization or removal of the lactic acid. This results in a raw material which can be used in the similar way as sweet whey. The most useful methods are based on membrane techniques and chromatography. With new techniques we can acquire single components which can be later used in dairy, meat and baking industry or in the dietary supplements production. From the viewpoint of dairy industry it is important to evaluate the process from the economic perspective and find a fine line between economic calculation and efficiency.

• Ključne besede: acid whey, chemical composition, minerals, lactic acid, proteins, functional foods, whey processing, chromatography, membrane techniques, side product