scholarly journals Influence of Freezing and Different Drying Methods on Volatile Profiles of Strawberry and Analysis of Volatile Compounds of Strawberry Commercial Jams

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4153
Author(s):  
Doaa Abouelenein ◽  
Ahmed M. Mustafa ◽  
Simone Angeloni ◽  
Germana Borsetta ◽  
Sauro Vittori ◽  
...  
Keyword(s):  
Microwave Drying ◽  
Drying Methods ◽  
Volatile Profile ◽  
Drying Method ◽  
Drying Process ◽  
Total Volatile ◽  
Ethyl Hexanoate ◽  
Complete Destruction ◽  
Freeze Dried ◽  
Volatile Profiles

Strawberry is the most consumed berry fruit worldwide due to its unique aroma and flavor. Drying fruits to produce a powder represents one of the possible conservation methods to extend their shelf-life. The aim of the present study was to compare the influence of freezing and different drying methods on the volatile profile of strawberry using the HS-SPME/GC–MS method, in addition to analysis of strawberry jam volatiles. A total of 165 compounds were identified, accounting for 85.03–96.88% of the total volatile compositions. Results and PCA showed that freezing and each drying process affected the volatile profile in a different way, and the most remarkable representative differential volatiles were ethyl hexanoate, hexyl acetate, (E)-2-hexenyl acetate, mesifurane, (E)-nerolidol, γ-decalactone, 1-hexanol, and acetoin. Shade air-dried, frozen, freeze-dried, and oven-dried 45 °C samples retained more of the fruity and sweet aromas of strawberry, representing more than 68% of the total aroma intensity according to the literature. In contrast, the microwave-drying method showed drastic loss of fruity esters. Strawberry jams demonstrated complete destruction of esters and alcohols in most jams, while terpenes were significantly increased. These findings help better understand the aroma of strawberry and provide a guide for the effects of drying, freezing, and jam processing.

Drying methods differentially alter volatile profiles of edible locusts and silkworms

2020 ◽  
Vol 6 (4) ◽  
pp. 405-415
Author(s):  
M. Mishyna ◽  
M. Haber ◽  
O. Benjamin ◽  
J.J. Itzhak Martinez ◽  
J. Chen
Keyword(s):  
Freeze Drying ◽  
Oxidation Process ◽  
Microwave Drying ◽  
Insect Species ◽  
Drying Methods ◽  
Drying Method ◽  
Headspace Volatiles ◽  
Volatile Profiles ◽  
Maillard Products ◽  
Different Levels

In this study, the effect of freeze-drying, oven- and microwave-drying on the volatile profiles and sensory properties of edible locust and silkworm was studied. Fifty-five headspace volatiles were detected, including alkanes, alcohols, aldehydes, esters, and ketones, with variations in intensity depending on the insect species and drying method. Volatiles from microwave-dried locusts and silkworms were typical for the Maillard reaction, that is in accordance with the significant increase of fluorescence of advanced Maillard products (2.9 and 5.5 times higher than in raw silkworms and locusts, respectively). Comparison of fatty acid composition and Fourier transform infrared spectra revealed signs of oxidation process at different levels depending on the insect. Changes in aroma and its intensity caused by different drying methods were also detected by sensory panellists who rated the samples of oven-dried locusts (2.4) and microwave-dried silkworms (1.9) with the lowest scores. An addition 15% of dried insects to cookies decreased the diversity of the volatiles, changed their intensity and lessened the dissimilarities between cookies with differently dried insect powders. Sensory panellists determined the presence of additional ingredients by higher odour intensity and general changes in overall liking scores of the insect-based cookies. Thus, drying can modify odour and sensory characteristics of locusts and silkworms and, consequently, cookies with these insect species, that should be considered in the processing of insects and formulation of novel insect-based foods.

Effect of drying methods on the nutritional content and In- vitro Antioxidant capacity of Chenopodium album L. and Spinacia oleracea L.

2021 ◽  
pp. 4361-4366
Author(s):  
Sonia Singh ◽  
Neetu Agrawal
Keyword(s):  
Spinacia Oleracea ◽  
Chenopodium Album ◽  
Microwave Drying ◽  
Total Phenolic ◽  
Drying Methods ◽  
Drying Method ◽  
Nutrient Quality ◽  
Oven Drying ◽  
Sun Drying ◽  
Hot Air

The herbs, Chenopodium album Linn. and Spinacia oleracea Linn. belongs to Chenopodiaceae family, are the two nutritious and edible green leafy food crops, abundantly found especially in the northern-west region of India. These plants have gained renown popularity, because of their high nutritional content including protein, amino acids, carbohydrate, and even the presence of phenolic components, which ultimately may get affected with drying and storage techniques. Impact of different drying methods (microwave drying at 4 minutes, hot air oven drying at 5 hours and sun drying at 8-10 hours) on nutrient quality and antioxidant property of Chenopodium album Linn. and Spinacia oleracea Linn. leaves were evaluated by using UV spectrophotometritc assay, total phenolic content and DPPH free radical scavenger method. Drying treatments were significantly decreased the moisture, carbohydrate and protein content present in C.album and S. oleracea. Hot air oven drying method produced dried samples of C.album and S. oleracea had significantly similar antioxidant activity when compared with the samples obtained from sun drying method. The dried samples obtained from hot air oven drying technique showed significant presence of total phenolic content in C. album and S. oleracea (6.44±0.12 mg/g, 6.69±0.40 mg/g) whilst the traditional sun drying method produced 8.00±0.02 mg/g and 7.89±0.37 mg/g). It is concluded that microwave drying and hot air oven drying were the methods to preserve appreciable percentage of nutrient components compared to the fresh samples. On other hand, the traditional method produced substantial reduction of nutrient quality. From statistical analysis, hot air oven drying technique was considered as optimum method which showed satisfactory % retention of protein (65.86%) and carbohydrate (85.95%) at 5 hours (shorter time than sun drying time period) along with significant antioxidant activity (34.89 μg/mL and 35.60 μg/mL) similar as obtained from the traditional technique (32.00 μg/mL).

scholarly journals Effect of Freeze, Oven and Microwave Pretreated Oven Drying on Color, Browning Index, Phenolic Compounds and Antioxidant Activity of Hawthorn (Crataegus orientalis) Fruit

2018 ◽  
Vol 46 (2) ◽  
pp. 449-456 ◽  
Author(s):  
Hacer COKLAR ◽  
Mehmet AKBULUT ◽  
Semih KILINC ◽  
Ali YILDIRIM ◽  
Iliasu ALHASSAN
Keyword(s):  
Antioxidant Activity ◽  
Phenolic Compounds ◽  
Total Phenolic Content ◽  
Phenolic Content ◽  
Total Phenolic ◽  
Drying Methods ◽  
Drying Method ◽  
Microwave Pretreatment ◽  
Oven Drying ◽  
Freeze Dried

Flowers, leaves and fruits of hawthorn plant are traditionally used for treating diseases like hypertension and atherosclerosis. The medicinal effects of the plant are generally attributed to its phenolic compounds. However, the fruits are perishable materials because of their high content of water, and generally dried and stored to be used outside its season. The main aim of this research was to investigate the effect of different drying methods on phenolic compounds of the hawthorn fruit. Fruits were collected from the wild growing trees in Turkey. De-seeded fruits were dried in freeze-, oven- (60 oC) and microwave pretreated oven drying (microwave application for 5 min at 360 W before drying at 60 oC) methods and analyzed for antioxidant activity, phenolic compounds, total phenolic content and color parameters. Total phenolic content of fresh hawthorn fruits was found as 13.36 mg g-1 DW. Oven- and microwave pretreated oven drying methods had a reductive effect on total phenolic content and antioxidant activity of fruits when compared to freeze drying method. (-)-Epicatechin (994.10 mg kg-1 DW), rutin (765.30 mg kg-1 DW), and procyanidin B2 (553.80 mg kg-1 DW) were the main phenolics of the fruit. Lowest values of these three compounds were observed in oven-dried fruits. Microwave pretreatment oven drying method resulted in browner product. Although the highest phenolic concentration and antioxidant activity were occurred in freeze-dried sample, microwave pretreatment before oven drying could be applied to reduce the time and cost of drying in terms of phenolic compounds and antioxidant activity.

scholarly journals Determination of Various Drying Methods’ Impact on Odour Quality of True Lavender (Lavandula angustifolia Mill.) Flowers

Molecules ◽  
2019 ◽  
Vol 24 (16) ◽  
pp. 2900 ◽  
Author(s):  
Łyczko ◽  
Jałoszyński ◽  
Surma ◽  
García-Garví ◽  
Carbonell-Barrachina ◽  
...  
Keyword(s):  
Solid Phase ◽  
Microwave Drying ◽  
Convective Drying ◽  
Drying Methods ◽  
Drying Method ◽  
Sensory Panel ◽  
Lavandula Angustifolia ◽  
Preservation Method ◽  
Vacuum Microwave

True lavender flowers (Lavandula angustifolia Mill.) is a critical source of essential oils and a flavouring agent used in numerous industries like foods, cosmetics and pharmaceuticals. Its main volatile constituents are linalool and linalyl acetate, which are commonly considered as main odour-active constituents (OACs). Nevertheless, the quality of true lavender flowers is highly dependent on its post-harvest treatment, mainly the preservation method. Recognising that drying is the most frequently used preservation method, the influence of various drying methods, including convective drying (CD) at 50, 60 and 70 °C, vacuum-microwave drying (VMD) with powers 240, 360 and 480 W and combined convective pre-drying at 60 °C followed by vacuum-microwave finish-drying with power 480 W (CPD-VMFD), on the quality of true lavender flowers was verified. The evaluation of influence was carried out by HS-SPME(HS, solid-phase microextraction), GC-MS, GC-MS-O (gas chromatography–mass spectrometry–olfactometry) techniques. Moreover, the sensory panel has assessed the sample odour quality. As a result, the optimal drying methods regarding the requirements for products were established. Overall, for total essential oil recovery, CD at 50 °C is the optimal drying method, while for odour quality concerning the sensory panel evaluation, VMD with power 360 W combined CPD-VMFD and CD at 50 °C is the optimal drying method.

Freeze-Drying Investigations of Antlers

2012 ◽  
Vol 195-196 ◽  
pp. 441-446
Author(s):  
Jun Liu ◽  
Shi Wei Zhang ◽  
Zhi Jun Zhang
Keyword(s):  
Freeze Drying ◽  
Eutectic Temperature ◽  
Tissue Structure ◽  
Chemical Compositions ◽  
Drying Method ◽  
Drying Process ◽  
Hot Air Drying ◽  
Air Drying ◽  
Hot Air ◽  
Freeze Dried

In this paper, the vacuum freeze-drying experiments of both antler slices and whole antlers are reported in details. The moisture content and the eutectic temperature of antler were measured. A 22 h process curve of antler slice freeze drying was obtained. The freeze drying process of whole antler was also investigated. The microscopic tissue structure was observed and chemical compositions were analyzed for those freeze-dried whole antlers in comparison with the traditional water boiling and hot air drying method. More nutrients were retained for freeze drying in addition to the better physical properties than traditional drying.

Effect of Blanching Duration and Drying Methods on the Proximate Composition of Green Chilies (Capsicum annuum L.)

2020 ◽  
Vol 7 (2) ◽  
pp. 75-83
Author(s):  
Tulsi Gurung ◽  
Karma Wangchuk ◽  
Bishal Sitaula
Keyword(s):  
Vitamin C ◽  
Nutritional Value ◽  
Fat Content ◽  
Hot Water ◽  
Drying Methods ◽  
Quality Changes ◽  
Drying Method ◽  
Drying Process ◽  
Sun Drying ◽  
Lower Temperature

Farmers in Bhutan practice hot water blanching and sun drying of green chillies as one of the preservation measures. The blanched dried chilli is known as ema shukam locally and is used in preparing various traditional cuisines. Blanching is done for 2-3 minutes by immersing in boiling water and drying in open sun. However, blanching and drying process lead to quality changes such as texture, colour, flavour, and nutritional value. Therefore, this study aimed to determine the proximate compositions of sun dried and oven dried green-blanched chillies. An experiment with two drying methods and two levels of blanching durations with three replications for each treatment were conducted to examine the proximate compositions of the dried and blanched chillies. Blanching duration of two minutes retained higher carbohydrates (x͂ = 31.78) than three minutes (x͂ = 26.08). However, the Mann-Whitney U test showed no significant effect of blanching duration on carbohydrate (U = 7.5, z = - .690, p > .05). Drying methods had significant effect only on fat content with oven drying retaining higher fat content (x͂ = 4) compared to sun drying method (x͂ = 2); (U = 2, z = -2.713, p < .01). Blanching for three minutes resulted in higher loss of Vitamin C content. The colour of oven dried chilli was dark brownish green even at lower temperature of 37 oC. Hot water blanching of green chillies for two minutes followed by sun drying produced desired colour of dried chillies.

Influence of drying method and ageing on chemical and physical properties andin vitrodegradation characteristics of grass and maize samples

1996 ◽  
Vol 126 (1) ◽  
pp. 7-14 ◽  
Author(s):  
J. W. Cone ◽  
A. H. Van Gelder ◽  
H. J. P. Marvin
Keyword(s):  
Physical Properties ◽  
Rumen Fluid ◽  
Sugar Content ◽  
Soluble Sugars ◽  
Drying Methods ◽  
Drying Method ◽  
Crude Fibre ◽  
Fermentation Kinetics ◽  
Freeze Dried

SUMMARYThe influence of different drying conditions on the chemical composition, physical properties,in vitroorganic matter degradability and fermentation kinetics of forages was investigated using young and old grass (Lolium perenne) samples (harvested on 15 June and 9 July 1992 at Lelystad, The Netherlands) and young and old maize (Zea mayscv. Scana) stem samples (harvested on 19 August and 30 September 1991 at Lelystad). The samples were either freeze-dried with a maximum sample temperature of 10 °C, dried in a vacuum at 20 °C or air-dried at 30, 50, 70 and 105 °C. The different drying methods had little effect on ash, acid detergent fibre (ADF), acid detergent lignin (ADL), crude fibre and crude protein (CP) contents andin vitrodegradation of the forage samples. However, some effects were found for sugars and phenolic acids. The neutral detergent fibre (NDF) content in protein-rich samples and the fermentation kinetics in rumen fluid differed significantly according to drying method. In samples dried other than by freeze-drying, proteins were bound to the NDF content and in some cases an effect on the amount of soluble sugars was also seen. Physical properties of the samples were determined by differential scanning calorimetry (DSC) and differences were found between freeze-dried materials and those dried at 70 °C. The influence of age on the maize samples was very pronounced, whereas it had little effect on the characteristics of the grass samples, with the exception of a decreased CP content and an increased sugar content after acid hydrolysis.

scholarly journals THE DIFFERENCE OF TENSILE STRENGTH AND YIELD FIBRINOGEN ON FIBRIN GLUE PREPARATIVE BY CRYOPRESIPITATE WITH AND WITHOUT FREEZE DRYING METHODS

2019 ◽  
Vol 25 (3) ◽  
pp. 349
Author(s):  
Brilliant Margalin ◽  
S. P. Edijanto ◽  
Paulus B. Notopuro
Keyword(s):  
Tensile Strength ◽  
Fibrin Glue ◽  
Freeze Drying ◽  
Drying Methods ◽  
Drying Process ◽  
Freeze Dried ◽  
Significant Difference ◽  
Fibrinogen Content

Fibrin glue is a useful biological product to stop bleeding, adhesive tissue and accelerate wound healing. Preparation of Fibrin Glue requires fibrinogen and thrombin components. The routine cryoprecipitation method performed at the Blood Bank can be used to improve the quality of the fibrinogen component. The Freeze Drying process can increase the retention time of plasma products at room temperature. Yield Fibrinogen and Tensile Strength is a quantitative and qualitative parameter of preparation quality of fibrin glue. This study focused on finding differences between Tensile Strength and Yield Fibrinogen on fibrin glue preparative by cryoprecipitate with and without freeze drying methods.This study is in vitro laboratory experiments design by comparing the Yield Fibrinogen and Tensile Strength of fibrin glue preparation from cryoprecipitic plasma with and without freeze dried process. The results were analyzed comparatively using paired T test.The plasma fibrinogen content of the sample was 237.66 ± 67.10 mg / dL. The fibrinogen content of the cryoprecipitate component without freeze drying process was 327.74 ± 103.42 mg / dL with a yield fibrinogen of 1.38 ± 0.25. The fibrinogen content of the cryoprecipitate component with freeze drying process was 251.20 ± 103.91 mg / dL with yield fibrinogen 1.04 ± 0.25. Tensile strength of fibrin glue from cryoprecipitate without freeze drying process was found to average 0.52 ± 0.18. Tensile strength of fibrin glue from cryoprecipitate with freeze drying process was found to average 0.33 ± 0.12. There was a significant difference between yield fibrinogen and tensile strength of fibrin glue preparation of cryoprecipitation method with and without freeze dried process.There is a significant difference on yields fibrinogen and tensile strength in the preparation of fibrin glue by the freeze drying process which is probably due to changes in the structure and function of fibrinogen proteins.

scholarly journals Effect of Freeze-drying and Oven-drying Methods on Flavonoids Content in two Romanian Grape Varieties

2019 ◽  
Vol 70 (2) ◽  
pp. 491-494
Author(s):  
Lacramioara Oprica ◽  
Radu Gheorghe Antohe ◽  
Andreea Verdes ◽  
Marius Nicusor Grigore
Keyword(s):  
Freeze Drying ◽  
Drying Methods ◽  
Drying Method ◽  
Vacuum Oven ◽  
Oven Drying ◽  
North East ◽  
Freeze Dried ◽  
Red Grape ◽  
Grape Varieties ◽  
Fresh Skin

The aims of this work was to investigate the effect of thermal drying method (vacuum oven drying), and nonthermal drying method (freeze drying) on the flavonoids content in two red grape varieties (Cabernet Sauvignon and Merlot) from different grape components (seed, skin, and pulp) collected from two experimental fields, Bucium and Copou (North East of Romania). In general, the fresh skin of Cabernet and Merlot varieties has the highest flavonoids content followed by those obtained by oven-drying and freeze-drying process. A similar situation was observed in the other component of grape varieties like pulp and seeds meaning in the way that the flavonoid content in oven-dried samples were higher than that in the freeze-dried samples. In addition, from both varieties, Merlot collected from Bucium presented the highest content compared with Cabernet.

Characterization and Photocatalytic Activity of TiO2 Nanoparticles with Precipitation Method Synthesis

2013 ◽  
Vol 750-752 ◽  
pp. 315-318
Author(s):  
Jin Huan Li ◽  
Jun Hui Hao ◽  
Wei Wang
Keyword(s):  
Photocatalytic Activity ◽  
Microwave Drying ◽  
Crystal Phase ◽  
Precipitation Method ◽  
Drying Methods ◽  
Mixed Solution ◽  
Drying Method ◽  
Ft Ir ◽  
Roasting Temperature

In this experiment, nanotitanium dioxide photocatalyst are prepared by treatment of a mixed solution of TiCl4and NH3·H2O. The conditions of synthesis catalyst are studied according to drying methods and roasting temperatures. The crystal phase of prepared powders is studied by XRD and FT-IR. At last we discussed photocatalysis activity of TiO2. The results show that the best roasting temperature is 500 °C and the optimal drying method is microwave drying.

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