Influence of Drying by Convective Air Dryer or Power Ultrasound on the Vitamin C and β-Carotene Content of Carrots

详细信息    查看全文

• 作者：Juana Frias ; Elena Peas ; Mnica Ullate ; Concepcin Vidal-Valverde
• 刊名：Journal of Agricultural and Food Chemistry
• 出版年：2010
• 出版时间：October 13, 2010
• 年：2010
• 卷：58
• 期：19
• 页码：10539-10544
• 全文大小：755K
• 年卷期：v.58,no.19(October 13, 2010)
• ISSN：1520-5118

文摘

Convective air drying and power ultrasound effects on vitamin C and β-carotene contents in carrots were studied. For convective air drying, a central composite face-centered design fitting temperature between 40 and 65 °C and air flow rate between 2 and 6 × 10⁻¹ m/s were used; previously, carrots were blanched. Likewise, ultrasound drying was performed on both unblanched and blanched carrots at 20, 40, and 60 °C for 120, 90, and 75 min, respectively. Blanching had a sharp effect on vitamin C and β-carotene degradation (80−92% retentions, respectively), and convective air drying led to further losses (32−50% and 73−90% retentions, respectively). According to the response surface model, a combination of 40 °C and 6 × 10⁻¹ m/s will maximize vitamin C retention in dried carrots, whereas 40 °C and 3.3 × 10⁻¹ m/s will ensure the highest β-carotene content. Ultrasound drying caused higher vitamin C and β-carotene retention (82−92% and 96−98%, respectively) than convective air drying. Blanched carrots dehydrated by ultrasound showed retentions of 55% and 88% of vitamin C and β-carotene, respectively. Ultrasound drying at 20 °C for 120 min caused the maximum vitamin C and β-carotene contents. Therefore, power ultrasound may be considered a valuable tool to obtain high nutritive dehydrated carrots.

Keywords:

Dehydrated carrots; air drying; ultrasound; blanching; vitamin C; β-carotene