| Abstract | Cilj ovog rada bio je odrediti utjecaj vremena tretmana, različitih amplituda te promjera sonde ultrazvuka visokog intenziteta na kvalitetu i stabilnost minimalno procesiranog krumpira (MPK) tijekom 8 dana skladištenja. Krumpir je oguljen i narezan na ploške, tretiran ultrazvukom u 2 % otopini natrijeva askorbata te vakumiran i skladišten na 4 °C. Ploške krumpira su tretirane ultrazvukom frekvencije 20 kHz, pri amplitudama 30 %, 60 % i 90 %, primjenom 3 različite sonde promjera 12,19 i 25 mm tijekom 3,5; 5,5; 7,5 i 9,5 minuta. Tijekom vremena skladištenja 1., 5., i 8. dan pratila se ukupna suha tvar, pH vrijednost, boja, tekstura i senzorska svojstva sirovog i kuhanog MPK. Najznačajniji utjecaj od triju ispitivanih sondi na sprječavanje enzimskog posmeđivanja imala je sonda promjera 19 mm i iz tog razloga je izabrana za nastavak istraživanja. Na ukupnu suhu tvar najveći utjecaj je imalo vrijeme skladištenja i toplinska obrada. Tretman ultrazvukom utjecao je na promjenu pH tijekom skladištenja. Najujednačenije odstupanje u promjeni boje pokazao je tretman ultrazvuka u trajanju od 7,5 minuta pri amplitudi od 90 %. Uzimanjem u obzir svih parametara senzorske ocjene vidljiv je pozitivan utjecaj tretmana na sprečavanje posmeđivanja, tekstura MPK ostala je gotovo nepromijenjena, uz povećanje kremoznosti, a ostvaren je i pozitivni utjecaj na miris MPK.Od svih primijenjenih varijacija tretman od 90 % i trajanju tretmana 7,5 minuta pokazuje najbolje rezultate u svim parametrima kvalitete kroz dane skladištenja. |
| Abstract (english) | The aim of this study was to evaluate the effect of treatment time, different amplitudes, and different diameter of probe by high intensity ultrasound on the quality and stability of minimally processed potatoes (MPP) during 8 days of storage. The potatoes were peeled and sliced, sonicated in 2% sodium ascorbate solution and vacuumed, and stored at 4 ° C. Potato plates were treated with 20 kHz ultrasound frequency at 30%, 60% and 90% amplitudes, using 3 different probes 12, 19 and 25 mm in diameter for 3.5; 5.5; 7.5; and 9.5 minutes. Dry matter content, pH, colour, texture, sensory analysis of raw and cooked MPP were monitored on the 1st, 5th, and 8th day of storage. The most significant influence of the three probes tested on the prevention of enzymatic browning had the 19 mm diameter probe, which is why it was chosen to continue the study. On the dry matter length of storage and cooking had the biggest effect. Ultrasound treatment caused a reduction in pH levels during storage. The most unique deviation in the change of color was demonstrated by the treatment of ultrasound for 7.5 minutes at an amplitude of 90%. Considering all the parameters of the sensory evaluation, there can be seen the positive effect of the treatment on the prevention of browning, the texture of MPP remained virtually unchanged, with increasing creaminess and a positive effect on the smells of MPP. Of all the variations applied, a treatment of 90% amplitude and a treatment duration of 7.5 minutes shows the best results in all quality parameters through the days of storage. |
