scholarly journals Drying kinetics, structural characteristics and vitamin C retention of dedo-de-moça pepper (Capsicum baccatum) during convective and freeze drying

2012 ◽  
Vol 29 (4) ◽  
pp. 741-750 ◽  
Author(s):  
A. O. M. Veras ◽  
R. Béttega ◽  
F. B. Freire ◽  
M. A. S. Barrozo ◽  
J. T. Freire
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xuemei Ma ◽  
Jiayi Yu ◽  
Jing Jing ◽  
Qian Zhao ◽  
Liyong Ren ◽  
...  

AbstractPectin is a kind of natural and complex carbohydrates which is extensively used in food, chemical, cosmetic, and pharmaceutical industries. Fresh sunflower (Helianthus annuus L.) heads were utilized as a novel source of pectin extracted by ammonium oxalate. The conditions of the extraction process were optimized implementing the response surface methodology. Under optimal extraction parameters (extraction time 1.34 h, liquid–solid ratio 15:1 mL/g, ammonium oxalate concentration 0.76% (w/v)), the maximum experimental yield was 7.36%. The effect of spray-drying and freeze-drying on the physiochemical properties, structural characteristics, and antioxidant activities was investigated by FT-IR spectroscopy, high performance size exclusion chromatography, and X-ray diffraction. The results showed freeze-drying lead to decrease in galacturonic acid (GalA) content (76.2%), molecular weight (Mw 316 kDa), and crystallinity. The antioxidant activities of pectin were investigated utilizing the in-vitro DPPH and ABTS radical-scavenging systems. This study provided a novel and efficient extraction method of sunflower pectin, and confirmed that different drying processes had an effect on the structure and properties of pectin.


Author(s):  
Petra Foerst ◽  
M. Lechner ◽  
N. Vorhauer ◽  
H. Schuchmann ◽  
E. Tsotsas

The pore structure is a decisive factor for the process efficiency and product quality of freeze dried products. In this work the two-dimensional ice crystal structure was investigated for maltodextrin solutions with different concentrations by a freeze drying microscope. The resulting drying kinetics was investigated for different pore structures. Additionally the three-dimensional pore structure of the freeze dried samples was measured by µ-computed tomography and the pore size distribution was quantified by image analysis techniques. The two- and three-dimensional pore size distributions were compared and linked to the drying kinetics.Keywords: pore size distribution; freeze drying; maltodextrin solution; freeze drying microscope   


Author(s):  
Ambe Desmond ◽  
Lobe Elias ◽  
Divine B. Nde

Potatoes (S. tuberosum L) is one of the most important tuber crops in the world. However, its high moisture content and inadequate storage and processing techniques have a negative influence on its quality and availability throughout the year. This work was carried out to optimize the blanching behavior and drying kinetics of potato slices. Fresh potato slices (5, 10 and 15 mm) were blanched at 70, 80 and 90°C for 1, 3 and 5 min following a 3k level full factorial design. The loss in Vitamin C was used as a quality marker for the optimization process. The influence of blanching on the drying behavior of potato slices was carried out at 50, 60 and 70°C. Results showed that blanching parameters had a significant (P < 0.05) effect on vitamin C loss. Optimum blanching conditions were blanching temperature of 80oC, blanching time of 3 min and a slice thickness of 10 mm which gave an average loss in Vitamin C of about 2.6%. Drying data were successfully fitted to three different thin layer drying models. The use of blanching as a pretreatment before the drying of potato is recommended because it reduces the drying time by 30%.


2017 ◽  
Vol 62 (1) ◽  
pp. 7-17
Author(s):  
Adina Ghirişan ◽  
◽  
Simion Drăgan ◽  
Vasile Miclăuş ◽  
◽  
...  

2017 ◽  
Vol 112 (3) ◽  
pp. 121-128
Author(s):  
Dorota Martysiak-Żurowska ◽  
Małgorzata Puta ◽  
Anna Rodzik ◽  
Edyta Malinowska-Pańczyk

Human milk is rich in polyunsaturated fatty acids, as well as lysozyme, vitamin C and other bioactive compounds. The effect of lyophilization on the content of antioxidants (vitamin C and catalase CAT), bactericidal compounds (lysozyme), total antioxidant capacity (TAC) and lipid peroxidation in human milk was investigated in this study. Samples of mature human milk were collected from five healthy women who gave birth on the scheduled date and without complications. Freeze drying resulted in the removal of 88.2 % of the initial water content from milk. The human milk lyophilizate was readily soluble in water. Lyophilization had no effect on the content of primary (lipid peroxides LP) and secondary (thiobarbituric acid reactive substances TBARS) products of lipid oxidation. Freeze-drying led to a significant decrease in the vitamin C content and TAC values of milk (by 31 % and 16.5 %, respectively). Catalase and lysozyme were resistant to freeze-drying. Lyophilization induced a decrease in lysozyme content (9 %) and catalase activity (11 %) but these changes were not statistically significant. Low-temperature dehydration and rehydration of human milk lyophilizates promote satisfactory retention of biologically active ingredients and prevent the oxidation of human milk lipids. The results of this study indicate that lyophilization can be considered as an effective method for prolonging the shelf life of human milk.


2016 ◽  
Vol 202 ◽  
pp. 189-198 ◽  
Author(s):  
Venu Perla ◽  
Padma Nimmakayala ◽  
Marjan Nadimi ◽  
Suresh Alaparthi ◽  
Gerald R. Hankins ◽  
...  

1998 ◽  
Vol 51 (3) ◽  
pp. 905-911 ◽  
Author(s):  
J. M. Saiter ◽  
N. Delahaye ◽  
A. Bardat ◽  
E. Chatenet

Author(s):  
Anna Sadowska ◽  
Franciszek Świderski ◽  
Rita Rakowska ◽  
Ewelina Hallmann

AbstractThe study evaluated the functional properties of chokeberry and kale powders obtained by the fluidised-bed jet milling with drying (FJMD) method compared to the freeze-drying (FD) method. The powders obtained by the FJMD method were characterised by low water activity (<0.3), vitamins C content of 320.2 mg/100 g d.m. for kale powder, total content of polyphenols of 1864.2 mg/100 g d.m. for chokeberry powder, antioxidant activity of 37.0 and 27.6 mmol Trolox/g d.m for chokeberry and kale powders respectively and sensory quality similar to raw material. The high content of vitamin C in the kale powder indicates the desirability of its greater use as a natural source of this vitamin. The properties of FJMD powders were similar to the functional properties of the FD powders, which indicate that the FJMD method can be very competitive as compared to FD method.


Sign in / Sign up

Export Citation Format

Share Document