Optimization of methods for rapid determination of water soluble vitamins in fruit extracts by liquid chromatography coupled with mass spectrometry

Zia, Hassan (avtor), Slatnar, Ana (mentor)

The dissertation presents the development and validation of two HPLC-MS/MS methods for analyzing water-soluble vitamins in fruit extracts. First method is a multivitamin analysis method for nine major B vitamins: thiamine (B1), riboflavin (B2), nicotinamide (B3-M), nicotinic acid (B3-A), pantothenic acid (B5), pyridoxine (B6), biotin (B7), folic acid (B9), and cyanocobalamin (B12). A HILIC-based HPLC-MS/MS method was developed to simultaneously analyze ascorbic acid (AA) and dehydroascorbic acid (DHA) as the combined amount of AA and DHA reflects the true total vitamin C content. The developed methods were validated according to ISO 21748 guidelines. The use of ammonium fluoride as an eluent modifier was investigated and was found to improve the MS sensitivity for the majority of vitamins significantly. The most profound increase was seen for B5, with a 15-fold increase in signal intensity. The effect was found to be non-additive as it did not improve with the increasing concentration of ammonium fluoride. The developed methods were also used to assess differences in vitamin retention in differently treated strawberry nectar with processing undertaken using pilot plants: conventional thermal processing (TT), high-pressure processing (HP), ohmic heating (OH), and pulse-electric field (PF). All processing techniques but HP were found to significantly increase total vitamin C content after processing, with the highest increases witnessed for TT-treated samples. The content of B vitamins remained largely unchanged after processing.

• Jezik: Angleški jezik
• Ključne besede: B vitamins, vitamin C, fruit extracts, HPLC-MS/MS, reverse phase, HILIC, ammonium fluoride, processing
• Vrsta gradiva: Doktorsko delo/naloga
• Tipologija: 2.08 - Doktorska disertacija
• Organizacija: BF - Biotehniška fakulteta
• Leto izida: 2024
• PID: 20.500.12556/RUL-165138
• COBISS.SI-ID: 216903171
• Datum objave v RUL: 24.11.2024

Sekundarni jezik

• Jezik: Slovenski jezik
• Naslov: Optimizacija metod za hitro določanje vodotopnih vitaminov v sadnih ekstraktih s tekočinsko kromatografijo sklopljeno z masno spektrometrijo

Izvleček

Doktorska disertacija predstavlja razvoj in validacijo dveh metod tekočinske kromatografije sklopljene z masno spektrometrijo (HPLC-MS/MS) za analizo v vodotopnih vitaminov v sadnih ekstraktih. Prva metoda je metoda multivitaminske analize za devet glavnih vitaminov skupine B: tiamin (B1), riboflavin (B2), nikotinamid (B3-M), nikotinska kislina (B3-A), pantotenska kislina (B5), piridoksin (B6), biotin (B7), folna kislina (B9) in cianokobalamin (B12). Razvita je bila HPLC-MS/MS metoda, ki temelji na hidrofilni interakciji tekočinske kromatografije (HILIC), za sočasno analizo askorbinske kisline (AA) in dehidroaskorbinske kisline (DHA), saj skupna količina AA in DHA odraža dejansko vsebnost vitamina C. Razvite metode so bile validirane v skladu s smernicami ISO 21748. Raziskana je bila uporaba amonijevega fluorida kot modifikatorja eluenta in ugotovljeno je bilo, da znatno izboljša MS občutljivost za večino vitaminov. Največje povečanje je bilo opaženo za B5, s 15-kratnim povečanjem intenzitete signala. Učinek se ni izboljšal z naraščajočo koncentracijo amonijevega fluorida. Razvite metode so bile uporabljene tudi za oceno razlik v zadrževanju vitaminov v različno obdelanih jagodnih nektarjih, pri čemer so bili uporabljeni pilotni postopki za: konvencionalno termično obdelavo (TT), tehnologija visokih tlakov (HP), ohmsko segrevanje (OH) in pulzirajoče električno polje (PF). Ugotovljeno je bilo, da so vse tehnike obdelave, razen HP, znatno povečale vsebnost vitamina C po obdelavi, pri čemer so največje povečanje pokazali vzorci obdelani s TT. Vsebnosti vitaminov skupine B so po obdelavi ostale večinoma nespremenjene.

• Ključne besede: vitamini, sadni sok, HPLC-MS/MS, tehnologija visokih tlakov, ohmsko segrevanje, pulzirajoče električno polje termična pasterizacija, kakovost