Freeze Drying Characteristics of Medicinal Herbs

Tambunan, Armansyah H.; Yudistira,; Kisdiyani,; HERNANI, .

doi:10.1081/drt-100102907

Cited by 42 publications

(18 citation statements)

References 2 publications

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“…Freeze drying as a low-temperature procedure (-50°C) is expected to cause less loss of aroma and quality [8,77]. In particular, freeze drying is superior compared to air drying for the drying of spearmint, dill and Celak [26,46,61], since the reduction in volatile compounds was greater in air-dried rather than freeze-dried herbs.…”

Section: Essential Oilmentioning

confidence: 99%

Drying Technologies: Vehicle to High-Quality Herbs

2015

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Herbs are usually marketed as dry due to a consumer demand beyond their seasonality; dehydration leads to a stable, easily moveable product that is available throughout the year. The process of drying, though, leads to modifications in the appearance, composition and quality of the raw material. The extent of these alterations depends on the applied drying methodology and its parameters, rendering the optimization of this process imperative. Numerous studies examining the effect of drying on the main characteristics of herbs have been published in recent years, and this review aims at organizing the available information of the studied herbs, drying methods and measured parameters in a comprehensive manner. Primarily, since aroma is the main characteristic of herbs and the principal aim for the end product is to retain the raw material's character, this review will focus on the most widely studied effect of drying, which is the essential oil yield and composition. Secondly, results from various studies on the influence of drying on biochemical compounds, organoleptic properties of dried herbs are also presented. The most common approach to the study of drying kinetics is also presented. Finally, novel technologies targeting to minimize the magnitude of changes from the raw material are described.

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Section: Essential Oilmentioning

confidence: 99%

Drying Technologies: Vehicle to High-Quality Herbs

2015

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“…Likewise, the amount of volatile compounds, phenolic contents, anthocyanins, and flavonols in grape skins were significantly lower in oven-dried samples in contrast to freeze-dried samples (de Torres et al 2010) and our previous study in wine grape pomace also found that freeze drying retains the highest level of bioactive compounds and DPPH radical scavenging activity compared with 40°C conventional, vacuum oven, and 25°C ambient air drying methods (Tseng and Zhao 2012). While freeze drying seems ideal, it can result in quality loss, as Tambunan et al (2001) indicated that the quality of the freezedried pomace is slightly lower than that of fresh material, but still remain considerably higher than that of oven dried samples. Still, the biggest drawback for both forced-air and freeze drying methods is the amount of time required, as much as 48 and 60 h, respectively, to reduce moisture content to~5-6 % (Tseng and Zhao 2012).…”

Section: Introductionmentioning

confidence: 97%

Impingement drying for preparing dried apple pomace flour and its fortification in bakery and meat products

2014

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This study aimed to evaluate impingement drying (ID) as a rapid drying method to dry wet apple pomace (WAP) and to investigate the fortification of dried apple pomace flour (APF) or WAP in bakery and meat products. ID at~110°C reduced the moisture content of apple pomace from 80 % (wet basis) to 4.5 % within 3 h, compared with 24 h to 2.2 % using 40°C forced-air drying and~60 h to 2.3 % using freeze drying. Furthermore, ID enhanced the extractable phenolic compounds, allowing for a 58 % increase in total phenolic content (TPC) compared with wet pomace, a 110 % and 83 % higher than TPC in forced-air dried and freeze dried samples, respectively. The 15-20 % APF-fortified cookies were found to be~44-59 % softer,~30 % more chewy, and~14 % moister than those of the control. WAP-fortified meat products had significantly higher dietary fiber content (0.7-1.8 % vs. 0.1-0.2 % in control) and radical scavenging activity than that of the control. These results suggest that impingement drying is a fast and effective method for preparing dried APF with highly retained bioactive compounds, and apple pomace fortified products maintained or even had improved quality.

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“…[12,13] From our previous research, the operation conditions of freeze drying were found to be significantly important to Correspondence: Mi-Jung Choi, Department of Food Science and Biotechnology of Animal Resources, Konkuk University, 1 Hwayang-dong Gwangjin-gu, Seoul 143-701, Korea; E-mail: foodeng301@paran.com stabilize nanocapsules. [12][13][14][15][16][17] Particularly, in a study related to the freezing process, Choi et al [17] reported that a lower freezing temperature was more efficient for maintaining the original size and morphological structure of nanoparticles. In order to modify the operating conditions of the freezing process during freeze drying, to enhance the stability of fish oil-loaded nanocapsules, we applied vacuum at the freezing stage during the process.…”

Section: Introductionmentioning

confidence: 99%

Physicothermal Properties of Freeze-Dried Fish Oil Nanocapsules Frozen under Different Conditions

et al. 2010

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This research compared the effects of vacuum freeze drying (VFD) and conventional freeze drying (CFD) processes on the stability of fish oil-loaded nanocapsules (NCs). For CFD, the NCs showed aggregation that was dependent on the freezing temperature. The encapsulation efficiency of CFD was greater than that of VFD, except at the freezing temperature of À30 C. From differential scanning calorimetry (DSC) analysis and scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images, it was concluded that the CFD process was more effective in the oxidative stability of the fish oil-loaded NCs. In addition, the vacuum-freezing process may affect the fragility of the poly-e-caprolactone membrane due to its low encapsulation efficiency and aggregation of particles. No differences in Zpotential values between the CFD samples were observed, whereas in the VFD samples, it became increased in the negative charge when decreasing the cooling temperature of the fish oil-loaded nanocapsules for the freeze-drying procedure. Regarding the observation of surface tension, CFD samples presented lower values than VFD samples at given freezing temperature.

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Freeze Drying Characteristics of Medicinal Herbs

Cited by 42 publications

References 2 publications

Drying Technologies: Vehicle to High-Quality Herbs

Drying Technologies: Vehicle to High-Quality Herbs

Impingement drying for preparing dried apple pomace flour and its fortification in bakery and meat products

Physicothermal Properties of Freeze-Dried Fish Oil Nanocapsules Frozen under Different Conditions

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