Tipo di tesi
Tesi di laurea magistrale
Titolo
Effect of advanced pretreatment technologies in Greek yogurt's production yield, sensory, physicochemical, and functional characteristics
Dipartimento
SCIENZE AGRARIE, ALIMENTARI E AGRO-AMBIENTALI
Corso di studi
BIOSICUREZZA E QUALITÀ DEGLI ALIMENTI
Parole chiave
- greek yogurt
- non-thermal processing
- pulsed electric fields (PEF)
Data inizio appello
06/10/2025
Consultabilità
Non consultabile
Data di rilascio
06/10/2028
Riassunto (Italiano)
This study evaluated pulsed electric fields (PEF) as a non-thermal pretreatment for Greek yogurt, compared with conventional pasteurization under realistic laboratory conditions. Whole cow’s milk inoculated with a commercial starter was processed in a 3^3 factorial design including PEF (monopolar square pulses) and matched thermal controls. Quality was assessed via pH and titratable acidity, reducing sugars (DNS), flow behavior on an MCR-72 rheometer, antioxidant capacity (DPPH, ABTS), RP-HPLC peptide fingerprints of EtOH-soluble and TCA/NPN fractions (C18, 30 °C, 60-min gradient), and a consumer CATA test. Two-way ANOVA found no main effect of inoculum and no Milk×Inoculum interaction (p>0.05), while results were significant in milk-dependent samples. RP-HPLC showed the expected predominance of hydrophobic peptides in a casein-rich matrix. Switching extraction from EtOH to TCA reduced the total area but increased the hydrophobic share (higher H/I), without practical changes in rheology or syneresis. Data readouts and CATA descriptors showed no persistent negative effect, indicating preservation of consumer-familiar quality. Overall, results support quality parity for PEF relative to thermal treatment, while suggesting a route to process intensification: shorter times, lower thermal load, and potential energy savings. Future work should quantify these gains and strengthen chromatographic and inferential sensory resolution.
