Izbrane lastnosti soka črnoplodne aronije (Aronia melanocarpa)

Narobe, Teja (avtor), Vidrih, Rajko (mentor)

Namen diplomske naloge je raziskati kemijsko sestavo soka aronije (Aronia mitschurinii) pridobljenega iz različno zrelih plodov. Zanimalo nas je, kako zrelost plodov in odgovarjajoča kemijska sestava vplivata na senzorične lastnosti soka. V treh različnih obdobjih zrelosti smo obrali sadeže aronije sorte 'Galacjanka' in iz njih iztisnili sok. Opravili smo analizo topne suhe snovi v treh vzorcih in dobili vrednosti 19,81 ± 0,01 °Brix, 21,23 ± 0,02 °Brix in 25,37 ± 0,03 °Brix, ki nam dobro prikazujejo naraščanje sladkorjev v soku. Izmerili smo antioksidativni potencial (AOP) v vzorcih z metodo DPPH? in dobili vrednosti 7673,20 ± 98,7 mg askorbinske kisline (AK)/L soka, 8471,9 ± 30,0 mg AK/L in 9987,58 ± 79,2 mg AK/L. Opravili smo tudi senzorično analizo z nešolanimi preskuševalci in preverili všečnost sokov z 9-točkovno hedonsko lestvico. Vzorec soka proizveden iz plodov drugega obiranja je bil potrošnikom najbolj všečen in so ga po hedonski lestvici ocenili z 'rahlo ugaja'. Prvi vzorec so ocenili z 'manj ugaja', medtem ko so tretji vzorec ocenili z 'niti ne ugaja, niti ugaja'. Hkrati smo tudi opravili preskus z lestvico z metodo razvrščanja glede na intenzivnost sladkosti in trpkosti soka. Prvi vzorec se je izkazal za najbolj trpkega in drugi vzorec kot najmanj trpek, pri sladkosti pa je intenzivnost naraščala in bila najvišja v tretjem vzorcu. Plodovi iz drugega obiranja so dali tudi najvišji izkoristek iztisnjenega soka. Optimalni čas obiranja aronije za pridelavo v sok je bil drugo obiranje, ko je sok dosegel vrednost 21 °Brix.

• Jezik: Slovenski jezik
• Ključne besede: črnoplodna aronija, Aronia mitschurinii, sok aronije, čas obiranja, antioksidanti, DPPH*, senzorične lastnosti
• Vrsta gradiva: Diplomsko delo/naloga
• Organizacija: BF - Biotehniška fakulteta
• Leto izida: 2019
• PID: 20.500.12556/RUL-109712
• Datum objave v RUL: 07.09.2019

Sekundarni jezik

• Jezik: Angleški jezik
• Naslov: Selected compounds in juice from chokeberry (Aronia mitschurinii)

Izvleček

The aim of the graduation thesis was to investigate the chemical composition of chokeberry (Aronia mitschurinii) juice produced from fruits of different maturity stage. We investigated how the fruit maturity and the corresponding chemical composition affects the sensory properties of the juice. Chokeberry fruits variety 'Galacjanka' were harvested in three different periods of maturity and were made to juice. The soluble solids of juice from first to last maturity stage amounted to 19.81 ± 0,1 °Brix, 21.23 ± 0,2 °Brix and 25.37 ± 0,3 °Brix respectively. The antioxidant potential (AOP) of juice was measured with DPPH? method and results were expressed as ascorbic acid (AK) equivalents. Juice AOP from first to last maturity stage were 7673,20 ± 98,7 mg AK / L, 8471,9 ± 30,0 mg AK / L and 9987,58 ± 79,2 mg AK / L. Sensory analysis were carried out with non-trained evaluators, results are expressed with liking degree on a 9-point hedon scale. Evaluators scored as the best juice from fruits from second maturity stage, they descriptevily expressed as 'like slightly'. The juice from first harvest was rated 'dislike slightly', while the third sample was rated with 'neither like nor dislike'. Evaluators also sorted juices according to the intensity of sweetness and astringency. The juice from first harvest was rated as the most astrigent, juice from the second harvest as the least astringent. The perceived sweetness was the lowest in juice from the first harvest and higest in juice from the third harvest. The highest yield of the extracted juice was obtained from the fruits from the second harvest. Results showed that juice from the second harvest had suitable chemical composition and was sensorially evaluated as the best.

• Ključne besede: chokeberry, Aronia mitschurinii, aronia juice, harvest, antioxidants, DPPH*, sensory properties