Preverjanje lastnosti sirotkinega koncentrata po nanofiltraciji

diplomsko delo univerzitetnega študijskega programa I. stopnje

Matija Zimšek (Author), Marjana Simonič (Mentor), Maja Bjelošević (Co-mentor)

Abstract

V diplomski nalogi smo obravnavali problem odpadnega materiala iz mlekarske industrije kisle sirotke ter preverili lastnosti sušenega koncentrata po nanofiltraciji (NF). Koncentrat je bil posušen z metodo sušenja z razprševanjem. Preučili smo tudi možnosti nadaljnje uporabe sušenega sirotkinega koncentrata. V eksperimentalnemu delu smo opravili NF kisle sirotke in vzorca izpirek gojišča. Najprej smo preverili odvisnost med transmembranskim tlakom (TMP) in fluksom J. Pred NF vzorcev smo skozi membrano izmerili pretok destilirane vode in izračunali fluks. Postopek smo ponovili po obdelavi vzorca. Optimalen TMP pri NF je 40 bar in pri tej vrednosti smo opravili kemijsko in mikrobiološko obdelav vzorcev. Z namenom, da bi čimbolj ločili laktozo in mlečno kislino, smo znižali pH z dodajanjem koncentrirane HCl. Najpogostejša tipa mašenja membran sta ustrezala modelu standardnega in popolnega mašenja por. Ugotovili smo, da membran ne bi bilo možno čistiti s protitokom, ampak bi bilo potreben dodatek kemičnih sredstev. V sodelovanju z BT in FFA na UL je bila opravljena kemijska in mikrobiološka analiza po NF. Kemijska analiza je pokazala, da je večinoma laktoza ostala v koncentratu kisle sirotke po NF pri TMP= 40 bar in pH= 4,7 (99,3 % rejekcija). Analiza povprečne velikosti delcev je to potrdila. Rejekcija laktoze je bila 100 % pri TMP= 40 bar in pH= 3,0. Z zniževanjem pH smo tako uspešno povečali rejekcijo laktoze v vzorcu kisle sirotke. Prav tako je bilo v permeatu razvidno veliko znižanje surovega pepela in anorganskih komponent. Za vzorec izpirek gojišča smo ugotovili, da vsebuje nižjo koncentracijo laktoze v primerjavi s kislo sirotko. Posledično je bilo tudi mašenje nižje. Rejekcija laktoze je bila 100 %, rejekcija mlečne kisline pa 57,5 %. Anorganska sestava je bila v permeatu in koncentratu podobna tisti od kisle sirotke. Mikrobiološka analiza je pokazala preveliko skupno število mikroorganizmov. Takšni mikrobiološki rezultati so zožali spekter uporabe tega koncentrata kisle sirotke. Njegova uporabna vrednost se bi tako našla v kremah za nego kože in šamponih za lase. Ob ustrezni predelavi za odstranitev neželenih bakterij pa se uporaba lahko razširi na prehrambeno industrijo.

Keywords

kisla sirotka;nanofiltracija;mašenje membran;laktoza;mlečna kislina;diplomske naloge;

Data

Language:	Slovenian
Year of publishing:	2020
Typology:	2.11 - Undergraduate Thesis
Organization:	UM FKKT - Faculty of Chemistry and Chemical Engineering
Publisher:	[M. Zimšek]
UDC:	543.95:637.344(043.2)
COBISS:	31907843
Views:	426
Downloads:	87
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	English
Secondary title:	The comparison of whey concentrate after nanofiltration
Secondary abstract:	In this study the problem of acid whey waste stream from diary industry is shown. Acid whey was processed with nanofiltration (NF) and retentate was dryed with methood of spray drying. Also some ideas for its usage are given. In the experimental part NF of acid whey and residue of kefir farm was processed. First, we examined the correlation between the transmembranic preassure (TMP) and fluks J. Before the NF of samples the flow rate of distilled water was measured and J was calculated. The process was repeated after the NF of sample. The optimum NF TMP is 40 bar and at this value the chemical and microbiological process of samples was carried out. With the purpose of separating the lactose and lactic acid as much as we can, the pH of sample was lowered with concencrated HCl. Most common membrane fouling mechanizems were standard and complete blocking. It was found out, that the membrane couldn't be washed with countercurrent so the extra chemical component would be needed. With the cooperation with BT and FFA UL the chemical and mikrobiological analysis was done. In the chemical part it was found out that in the retentate of acid whey processed at TMP= 40 bar and pH= 4,7 with 99,3 % lactose rejection. Average size analysis confirmed this statement. Total rejection of lactose in comparisson with the sample processed at TMP= 40 bar and pH= 3,0 was achieved. Also, the level of raw ash and inorganic compounds was lowered in the peremeate. For the sample of kefir residue it was found out that it contained less lactose compared to acid whey. Thus, its membrane fouling was lower. Lactose rejection reached 100 % and rejection of lactic acid 57,5 %. Anorganic composition in the retentate and permeate was similar to that of acid whey sample. Microbiological analysis, on the other hand, showed increased number of total microorganisms. This results have gretly decreased the spectre of retentate application. It can be used as cream for skin conditioning and hear shampoo ingredient. But with the correct processing of terminating the unwanted microorganizms it can be used in food industry.
Secondary keywords:	acid whey;nanofiltration;membrane fouling;lactose;lactic acid;
Type (COBISS):	Bachelor thesis/paper
Thesis comment:	Univ. v Mariboru, Fak. za kemijo in kemijsko tehnologijo
Pages:	X, 54 str.
ID:	11985275