The dipping of berries in a dilute solution of sodium hydroxide during a short time was evaluated as pretreatment undertaken prior to convective dehydration of wine grapes. The impact of the sodium hydroxide content and dipping time on weight loss (WL) at different dehydration times was thoroughly assessed using central composite design (CCD) and response surface methodology (RSM). Furthermore, the effects of these two variables were also investigated on the skin mechanical properties of dehydrated grapes. The effect of these two pretreatment factors on the dehydration kinetics and skin hardness was satisfactorily fitted to regression models. The berry pretreatment with low sodium hydroxide contents (from 10 to 20 g/L) facilitated the dehydration process during the first 5 days when dipping times longer than 300 s were used. From the seventh day of dehydration, at which time the average WL% was close to 50, the highest values of WL% were obtained using intermediate sodium hydroxide contents and dipping times (around 45 g/L and 185 s, respectively). Because skin hardness affects the dehydration kinetics during postharvest withering, the strongest decrease in skin hardness corresponded to these last berry pretreatment conditions, whereas the greatest increase required the highest sodium hydroxide contents and longest dipping times. The quality of berries dehydrated may be influenced by the pretreatment conditions used, and the present study contributes to increase the knowledge on this effect to a better management of the alkaline pretreatment and dehydration process.

Assessment of Postharvest Dehydration Kinetics and Skin Mechanical Properties of “Muscat of Alexandria” Grapes by Response Surface Methodology

GIACOSA, SIMONE;RIO SEGADE, SUSANA;GERBI, Vincenzo;ROLLE, Luca Giorgio Carlo
2016

Abstract

The dipping of berries in a dilute solution of sodium hydroxide during a short time was evaluated as pretreatment undertaken prior to convective dehydration of wine grapes. The impact of the sodium hydroxide content and dipping time on weight loss (WL) at different dehydration times was thoroughly assessed using central composite design (CCD) and response surface methodology (RSM). Furthermore, the effects of these two variables were also investigated on the skin mechanical properties of dehydrated grapes. The effect of these two pretreatment factors on the dehydration kinetics and skin hardness was satisfactorily fitted to regression models. The berry pretreatment with low sodium hydroxide contents (from 10 to 20 g/L) facilitated the dehydration process during the first 5 days when dipping times longer than 300 s were used. From the seventh day of dehydration, at which time the average WL% was close to 50, the highest values of WL% were obtained using intermediate sodium hydroxide contents and dipping times (around 45 g/L and 185 s, respectively). Because skin hardness affects the dehydration kinetics during postharvest withering, the strongest decrease in skin hardness corresponded to these last berry pretreatment conditions, whereas the greatest increase required the highest sodium hydroxide contents and longest dipping times. The quality of berries dehydrated may be influenced by the pretreatment conditions used, and the present study contributes to increase the knowledge on this effect to a better management of the alkaline pretreatment and dehydration process.
9
6
1060
1069
http://link.springer.com/article/10.1007%2Fs11947-016-1697-y
Grape dehydration kinetics; Alkaline pretreatment; Berry skin mechanical properties; Response surface methodology; Muscat of Alexandria grapes
Corona, Onofrio; Torchio, Fabrizio; Giacosa, Simone; RIO SEGADE, Susana; Planeta, Diego; Gerbi, Vincenzo; Squadrito, Margherita; Mencarelli, Fabio; Rolle, Luca Giorgio Carlo
File in questo prodotto:
File Dimensione Formato  
Corona et al 2016.pdf

non disponibili

Tipo di file: PDF EDITORIALE
Dimensione 978.13 kB
Formato Adobe PDF
978.13 kB Adobe PDF   Visualizza/Apri   Richiedi una copia
Corona et al 2016 AperTO.pdf

embargo fino al 01/07/2017

Tipo di file: POSTPRINT (VERSIONE FINALE DELL’AUTORE)
Dimensione 647.8 kB
Formato Adobe PDF
647.8 kB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/2318/1567321
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 6
  • ???jsp.display-item.citation.isi??? 5
social impact