Impact of freeze‐drying conditions on the sensory perception of a freeze‐dried orange snack

2021 ◽  
Author(s):  
Marilú Andrea Silva‐Espinoza ◽  
Ana Salvador ◽  
María del Mar Camacho ◽  
Nuria Martínez‐Navarrete
Keyword(s):  
Freeze Drying ◽  
Sensory Perception ◽  
Freeze Dried ◽  
Drying Conditions

Effect of culture age, protectants, and initial cell concentration on viability of freeze-dried cells ofMetschnikowia pulcherrima

2010 ◽  
Vol 56 (10) ◽  
pp. 809-815 ◽  
Author(s):  
Davide Spadaro ◽  
Annalisa Alessandra Ciavorella ◽  
Jorge Giovanny Lopez-Reyes ◽  
Angelo Garibaldi ◽  
Maria Lodovica Gullino
Keyword(s):  
Freeze Drying ◽  
Cell Concentration ◽  
Yeast Cells ◽  
Initial Cell Concentration ◽  
Commercial Development ◽  
Culture Age ◽  
Biocontrol Efficacy ◽  
High Viability ◽  
Freeze Dried ◽  
Drying Conditions

The effect of freeze-drying using different lyoprotectants at different concentrations on the viability and biocontrol efficacy of Metschnikowia pulcherrima was evaluated. The effects of initial yeast cell concentration and culture age on viability were also considered. Yeast cells grown for 36 h were more resistant to freeze-drying than were 48 h cells. An initial concentration of 108cells·mL–1favoured the highest survival after freeze-drying. When maltose (25%, m/v) was used as protectant, a high cell viability was obtained (64.2%). Cells maintained a high viability after 6 months of storage at 4 °C. The biocontrol efficacy of freeze-dried cells was similar to the activity of fresh cells on ‘Gala’ apples and was slightly lower on ‘Golden Delicious’ apples. After optimizing freeze-drying conditions, the viability of M. pulcherrima cells was similar to that obtained in other studies. The results constitute a first step towards the commercial development of M. pulcherrima as a biocontrol agent.

scholarly journals Evaluation of freeze-drying conditions on the process kinetics and physicochemical properties of purple shallot

Food Research ◽  
2020 ◽  
Vol 4 (5) ◽  
pp. 1630-1636
Author(s):  
N.M. Thuy ◽  
N.T.M. Tuyen ◽  
N.V. Thanh ◽  
N.V. Tai
Keyword(s):  
Moisture Content ◽  
Freeze Drying ◽  
Chemical Properties ◽  
Sample Pretreatment ◽  
Freezing Temperature ◽  
Moisture Diffusivity ◽  
Freezing Time ◽  
Freeze Dried ◽  
Thin Layer Drying ◽  
Drying Conditions

Purple shallot is an important vegetable crop in Vietnam and throughout the world. Its storage is difficult hence, it is dehydrated for value addition. Freeze drying is one of the options for dehydration of purple shallot. There are two main stages (freezing and drying) in the complete freeze-drying process after sample pretreatment. In this study, the sample was frozen at different temperatures and times (-20 to -60oC and 5 to 9 hrs, respectively). Controlling the selected temperature (from the second stage) and pressure 0.001 mbar, eight thin layer drying models were fitted to the experimental moisture content. The physical and chemical properties and antioxidant capacity of freeze-dried purple shallot were evaluated. The obtained results showed that the TPC values and DPPH% almost increased as the freezing time increased at the same freezing temperature. The best drying conditions were found at a freezing time of 7 hrs, freezing temperature of -60oC, a pressure of 0.001 mbar, and a lyophilization time of 12 hrs. Under these conditions, the moisture content, TPC and DPPH% of the final product were 1.56%, 16.95 mg GAE/g and 65.67%, respectively. Among the models proposed, Page's model gave a better fit for the freeze-drying condition used. In freeze-drying, effective moisture diffusivity was estimated to be 5.68×10-7 m 2 /s within the conditions studied.

scholarly journals The Impact of Freeze-Drying Conditions on the Physico-Chemical Properties and Bioactive Compounds of a Freeze-Dried Orange Puree

Foods ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 32 ◽  
Author(s):  
Marilú A. Silva-Espinoza ◽  
Charfedinne Ayed ◽  
Timothy Foster ◽  
María del Mar Camacho ◽  
Nuria Martínez-Navarrete
Keyword(s):  
Vitamin C ◽  
Water Content ◽  
Freeze Drying ◽  
Low Pressure ◽  
High Water Content ◽  
Freeze Dried ◽  
Drying Conditions ◽  
The Impact ◽  
Shelf Temperature ◽  
Β Carotene

Fruits are essential for a healthy diet, as they contribute to the prevention of cardiovascular diseases and some cancers, which is attributed to their high bioactive compound content contributing to their antioxidant capacity. Nevertheless, fruits have a short shelf life due to their high-water content, and freeze-drying is a well-known technique to preserve their nutritive quality. However, it is an expensive technology, both due to the use of low pressure and long processing time. Therefore, an optimisation of variables such as the freezing rate, working pressure and shelf temperature during freeze-drying may preserve fruit quality while reducing the time and costs. The impact of these variables on colour, porosity, mechanical properties, water content, vitamin C, total phenols, β-carotene, and antioxidant activity of a freeze-dried orange puree was evaluated. The results showed a great impact of pressure and shelf temperature on luminosity, chroma and water content. Vitamin C and β-carotene were more preserved with higher shelf temperatures (shorter times of processing) and lower pressure, respectively. The optimum freeze-drying conditions preserving the nutrients, and with an interesting structural property, perceived as a crunchy product by consumers, are low pressure (5 Pa) and high shelf temperature (50 °C).

Influence of the Freeze-drying Conditions on the Physicochemical Properties and Grinding Characteristics of Kiwi

2020 ◽  
Vol 16 (1-2) ◽  
Author(s):  
Marek Domin ◽  
Dariusz Dziki ◽  
Sybilla Kłapsia ◽  
Agata Blicharz-Kania ◽  
Beata Biernacka ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Freeze Drying ◽  
Average Particle Size ◽  
Antioxidant Properties ◽  
Average Particle ◽  
Freeze Dried ◽  
Energy Indices ◽  
Dried Fruit ◽  
Phenolics Content ◽  
Drying Conditions

AbstractThe aim of this work was to study the influence of freeze-drying conditions of kiwi (Actinidia deliciosa) on physicochemical properties and grinding characteristics of dried fruits. Whole kiwi fruits were freeze-dried with the different pressure: 12, 20, 42, 63, 85, and 103 Pa. Dried fruit properties that underwent evaluation included color, texture, rehydration, total phenolics content, antioxidant properties and sensory analysis. Moreover, the grinding energy indices of dried kiwi were determined. The results showed that an increase in the pressure caused decreased lightness, but increased yellowness and greenness of freeze-dried kiwi. The force of kiwi penetration increased and the rehydration ability decreased with the increase in the pressure. The specific grinding energy of dried kiwi ranged from 10.1 to 13.6 kJ⋅kg−1, whereas the average particle size of kiwi powder changed from 0.331 to 0.337 mm. The highest values of these parameters were obtained for kiwi freeze-dried with the highest pressure.

scholarly journals Reeze-Drying Impact on Hardness of Selected Soft Fruit Liophilisates

2021 ◽  
Vol 25 (1) ◽  
pp. 135-146
Author(s):  
Marek Domin ◽  
Magdalena Ćwiklińska ◽  
Małgorzata Góral-Kowalczyk
Keyword(s):  
Freeze Drying ◽  
Grape Pomace ◽  
Raw Material ◽  
Pressing Process ◽  
Freeze Dried ◽  
Soft Fruit ◽  
Fruit Pomace ◽  
Drying Conditions ◽  
The Impact ◽  
Rotary Press

Abstract The objective of the paper was to describe the impact of freeze-drying conditions on hardness of lyophilizates obtained based on soft fruit pomace. Raspberry, cherry, and grape pomace from the pressing process carried out with a low-speed rotary press constituted a research material. Immediately after the pressing process, pomaces were placed in forms, frozen, and after freezing they were freeze-dried in the pressure of 20, 42, 63, 85 and 110 Pa. The obtained lyophilizates were subjected to the measurement of hardness with the use of texture meter equipped with a penetrometer in the form of a cone with a vertical angle of 30°. The increase of pressure during freeze-drying of samples was accompanied by the increase of hardness of the obtained lyophilizates, which may affect the energy consumption of the grinding process and the nature of rehydration of the final product. Moreover, the water content of raw material, pomaces, and lyophilizates was determined. The obtained results of measurements were subjected to a statistical analysis which showed that the pressure of freeze-drying significantly diversifies the hardness of the obtained lyophilizates.

Scanning Electron Microscopy-cuticular Lesions on the Roundworm Ascaris Suum

1970 ◽  
Vol 28 ◽  
pp. 114-115
Author(s):  
P. A. Madden ◽  
W. R. Anderson
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Freeze Drying ◽  
Room Temperature ◽  
Secondary Electron ◽  
Distilled Water ◽  
Freeze Dried ◽  
Silver Paint ◽  
To Come ◽  
Scanning Electron

The intestinal roundworm of swine is pinkish in color and about the diameter of a lead pencil. Adult worms, taken from parasitized swine, frequently were observed with macroscopic lesions on their cuticule. Those possessing such lesions were rinsed in distilled water, and cylindrical segments of the affected areas were removed. Some of the segments were fixed in buffered formalin before freeze-drying; others were freeze-dried immediately. Initially, specimens were quenched in liquid freon followed by immersion in liquid nitrogen. They were then placed in ampuoles in a freezer at −45C and sublimated by vacuum until dry. After the specimens appeared dry, the freezer was allowed to come to room temperature slowly while the vacuum was maintained. The dried specimens were attached to metal pegs with conductive silver paint and placed in a vacuum evaporator on a rotating tilting stage. They were then coated by evaporating an alloy of 20% palladium and 80% gold to a thickness of approximately 300 A°. The specimens were examined by secondary electron emmission in a scanning electron microscope.

Revealing gross three-dimensional structure in the SEM

1987 ◽  
Vol 45 ◽  
pp. 656-657
Author(s):  
Sterling P. Newberry
Keyword(s):  
Freeze Drying ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Small Object ◽  
Final Solution ◽  
Dimensional Representation ◽  
X Ray ◽  
Three Dimensional Representation ◽  
Freeze Dried ◽  
Critical Point Drying

The beautiful three dimensional representation of small object surfaces by the SEM leads one to search for ways to open up the sample and look inside. Could this be the answer to a better microscopy for gross biological 3-D structure? We know from X-Ray microscope images that Freeze Drying and Critical Point Drying give promise of adequately preserving gross structure. Can we slice such preparations open for SEM inspection? In general these preparations crush more readily than they slice. Russell and Dagihlian got around the problem by “deembedding” a section before imaging. This some what defeats the advantages of direct dry preparation, thus we are reluctant to accept it as the final solution to our problem. Alternatively, consider fig 1 wherein a freeze dried onion root has a window cut in its surface by a micromanipulator during observation in the SEM.

scholarly journals Effect of Freeze Drying and Simulated Gastrointestinal Digestion on Phenolic Metabolites and Antioxidant Property of the Natal Plum (Carissa macrocarpa)

Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1420
Author(s):  
Faith Seke ◽  
Vimbainashe E. Manhivi ◽  
Tinotenda Shoko ◽  
Retha M. Slabbert ◽  
Yasmina Sultanbawa ◽  
...  
Keyword(s):  
Freeze Drying ◽  
Array Detector ◽  
Gastrointestinal Digestion ◽  
Liquid Chromatograph ◽  
Antioxidant Power ◽  
Intestinal Phase ◽  
Glucosidase Activity ◽  
Freeze Dried ◽  
Small Intestinal ◽  
The Impact

Natal plums (Carissa macrocarpa) are a natural source of bioactive compounds, particularly anthocyanins, and can be consumed as a snack. This study characterized the impact of freeze drying and in vitro gastrointestinal digestion on the phenolic profile, antioxidant capacity, and α-glucosidase activity of the Natal plum (Carissa macrocarpa). The phenolic compounds were quantified using high performance liquid chromatography coupled to a diode-array detector HPLC-DAD and an ultra-performance liquid chromatograph (UPLC) with a Waters Acquity photodiode array detector (PDA) coupled to a Synapt G2 quadrupole time-of-flight (QTOF) mass spectrometer. Cyanidin-3-O-β-sambubioside (Cy-3-Sa) and cyanidin-3-O-glucoside (Cy-3-G) were the dominant anthocyanins in the fresh and freeze-dried Natal plum powder. Freeze drying did not affect the concentrations of both cyanidin compounds compared to the fresh fruit. Both cyanidin compounds, ellagic acid, catechin, epicatechin syringic acid, caffeic acid, luteolin, and quercetin O-glycoside from the ingested freeze-dried Natal plum powder was quite stable in the gastric phase compared to the small intestinal phase. Cyanidin-3-O-β-sambubioside from the ingested Natal plum powder showed bioaccessibility of 32.2% compared to cyanidin-3-O-glucoside (16.3%). The degradation of anthocyanins increased the bioaccessibility of gallic acid, protocatechuic acid, coumaric acid, and ferulic acid significantly, in the small intestinal digesta. The ferric reducing antioxidant power (FRAP), 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) activities, and inhibitory effect of α-glucosidase activity decreased in the small intestinal phase. Indigenous fruits or freeze-dried powders with Cy-3-Sa can be a better source of anthocyanin than Cy-3-G due to higher bioaccessibility in the small intestinal phase.

Process for production of microencapsulated anthocyanin pigments from Rosa pimpinellifolia L. fruits: optimization of aqueous two-phase extraction, microencapsulation by spray and freeze-drying, and storage stability evaluation

2020 ◽  
Vol 16 (9) ◽  
Author(s):  
Halil İbrahim Odabaş ◽  
Ilkay Koca
Keyword(s):  
Freeze Drying ◽  
Fold Increase ◽  
Drying Methods ◽  
Phase Extraction ◽  
Extraction Temperature ◽  
Two Phase ◽  
Freeze Dried ◽  
Anthocyanin Pigments ◽  
Promising Source ◽  
Aqueous Two Phase Extraction

AbstractRosa pimpinellifolia L. fruits (RPF) are promising source of anthocyanin pigments. The objectives of this study were to optimization of the aqueous two-phase extraction (ATPE) process of anthocyanin from RPF and microencapsulation of anthocyanin-rich RPF extract. The optimal ATPE conditions were as follows: 0% HCl, 30% ethanol, 19% ammonium sulfate, and liquid to solid ratio 51.71, 97.71 min, and 30°C extraction temperature. Predicted anthocyanin yield at the optimum conditions was 1578.90 mg cyanidin 3-glucoside equivalent/100 g dry fruit. ATPE resulting in 1.80-fold increase in the purity of anthocyanins when compared to conventional solvent extraction (CSE). The composition of the anthocyanins were determined with HPLC-QTOF-MS. Freeze-drying and spray-drying methods were employed for the production of microencapsulated anthocyanin pigments. The half times of microencapsulated anthocyanins at 4, 25 and 37°C were determined as 12.16, 6.60 and 3.12 months for freeze-dried microcapsules, and 16.50, 9.24 and 4.29 months for spray-dried microcapsules, respectively.

Preparation and Characterization of Chitosan-Based Scaffolds for Biomedical Applications

2006 ◽  
Vol 514-516 ◽  
pp. 1005-1009 ◽  
Author(s):  
José V. Araújo ◽  
J.A. Lopes da Silva ◽  
Margarida M. Almeida ◽  
Maria Elisabete V. Costa
Keyword(s):  
Biomedical Applications ◽  
Freeze Drying ◽  
Average Pore Size ◽  
Composite Scaffolds ◽  
Average Pore ◽  
Chitosan Matrix ◽  
Freeze Dried ◽  
Porous Chitosan ◽  
Interconnected Structure

Porous chitosan/brushite composite scaffolds were prepared by a freeze-drying technique, starting from brushite suspensions in chitosan solutions. The obtained scaffolds showed a regular macroporous and interconnected structure with brushite particles uniformly distributed in the chitosan matrix. The variation of the brushite concentration affected the microstructure of the final freeze-dried scaffold, in particular, its porosity and its average pore size. The yield strengths of the composite scaffolds could also be improved by the increase of the brushite content.

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