scholarly journals Effect of lacto-fermentation and freeze-drying on the quality of beetroot evaluated using machine vision and sensory analysis

Author(s):  
Ewa Ropelewska ◽  
Anna Wrzodak ◽  
Kadir Sabanci ◽  
Muhammet Fatih Aslan

AbstractThis study was aimed at evaluating the effect of freeze-drying and lacto-fermentation on the texture parameters of images and sensory attributes of beetroots. The samples were imaged using a flatbed scanner, and textures from images converted to color channels L, a, b, R, G, B, X, Y, Z were computed. The discrimination of raw and processed beetroots was performed using models based on textures selected for each color channel. The sensory quality of processed samples was determined using the attributes related to smell, color, texture and taste. The highest discrimination accuracy of 97.25% was obtained for the model built for color channel b. The accuracies for other channels were equal to 96.25% for channel a, 95.25% for channel R, 95% for channel Y, 94.75% for channel B, 94.5% for channel X, 94% for channel L, 92.5% for channel G, 88.25% for channel Z. In the case of some models, the raw and lacto-fermented beetroots were discriminated with 100% correctness. The freeze-dried and freeze-dried lacto-fermented samples were also the most similar in terms of sensory attributes, such as off-odor, attractiveness color, beetroot color, crunchiness, hardness, bitter taste, overall quality. The results indicated that the image parameters and sensory attributes may be related.

Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1242
Author(s):  
Katarzyna Świąder ◽  
Anna Florowska ◽  
Zuzanna Konisiewicz

Set type yoghurts are characterised by a semi-solid texture, which is created during the fermentation process. The tea infusion in this type of yoghurt production can influence the quality of the final product. Therefore, the aim of the experiment was to evaluate the influence of the addition of 3, 6 and 9% inulin to oolong tea-infused yoghurts on the sensory quality. It has been evaluated by trained experts using a Quantitative Descriptive Profile analysis and by consumers using hedonic scaling, as well as on instrumentally evaluated features such as texture, stability and visual parameters. The addition of oolong tea to yoghurt resulted in positive changes in the perception of sweet, peach and nectar odours and flavours, and also creaminess, as well as negative changes in the presence of a bitter taste, the whey presence and a colour intensification towards dark cream (p ≤ 0.05). The addition of inulin to the tested oolong tea yogurts caused a decrease in the whey presence and brightened the yoghurt’s colour (6% and 9%, p ≤ 0.05, respectively), as well as an improved creaminess and an increase in the sweet taste of the yoghurt. It was also observed that the addition of oolong tea deteriorated the instrumentally evaluated texture of the set yoghurts, while inulin at a higher concentration (9%, p ≤ 0.05) increased the firmness and adhesiveness. Moreover, the addition of inulin also had a positive effect on the yoghurt’s stability. The addition of inulin to oolong tea-infused set yoghurts may be valuable both as a source of prebiotic fibre in functional products and as a factor improving the quality of these products.


Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 226
Author(s):  
Katarzyna Rybak ◽  
Artur Wiktor ◽  
Dorota Witrowa-Rajchert ◽  
Oleksii Parniakov ◽  
Małgorzata Nowacka

It has been demonstrated previously in the literature that utilization of PEF or a combination of a pulsed electric field (PEF) and ultrasounds (US) can facilitate dehydration processes and improve the quality of dried products even better than the application of thermal methods such as blanching. The aim of the study was to evaluate the quality of red bell pepper subjected to freeze-drying preceded by blanching or PEF or US treatment applied in a single and combined mode. Furthermore, the freeze-drying was preceded by shock freezing or vacuum freezing performed inside the freeze-dryer as a result of pressure drop during the first stage of freeze-drying. All of the analyzed technological variants enhanced the drying kinetics when compared to the intact material. Freeze-dried bell pepper subjected to non-thermal pretreatment exhibited higher vitamin C, total phenolic and carotenoids content than blanched material despite the fact that blanching reduced drying time the most compared to all other analyzed methods.


2022 ◽  
Vol 10 (1) ◽  
pp. 61
Author(s):  
Tarq Binalshikh-Abubkr ◽  
Marlia Mohd Hanafiah

Supplementation of dried bioflocs for red hybrid tilapia (Oreochromis sp.) was examined during 57 days of feeding trials. Five experimental treatments; T1 (the control; without bioflocs), T2 (4% freeze-dried bioflocs), T3 (16% freeze-dried bioflocs), T4 (4% oven-dried bioflocs), and T5 (16% oven-dried bioflocs) were prepared to examine the water quality, growth performance and body composition of red hybrid tilapia. T2 and T4 treatments resulted in a higher growth rate and survival similar to the control, while T3 and T5 treatments showed the lowest values of growth performance among all treatments. T1 treatment showed the best quality of culture water followed by T2 and T4 treatments, while T3 treatment resulted in poor water quality followed by T5 treatment. Based on these results, the ratios of bioflocs (4% and 16%) had more effect on fish growth and water quality than the drying methods (freeze-drying and oven-drying). The ratio of 4% freeze-dried or oven-dried bioflocs provided higher growth rates and better water quality parameters similar to the control, while the ratio of 16% showed the worst growth performance and water quality in the present study. In addition, body compositions of tilapia fed 4% dried bioflocs showed better nutritional value than tilapia fed 16% dried bioflocs. Protein and energy levels showed an increasing trend with decreasing supplement levels of bioflocs. Moisture content was significantly higher when supplementation of 16% bioflocs was used. Overall, supplementation of 4% freeze-dried or oven-dried bioflocs can be successively included in red hybrid tilapia diets without any effects on growth or body composition and can result in a good quality of culture water for red hybrid tilapia.


J ◽  
2021 ◽  
Vol 4 (3) ◽  
pp. 430-443
Author(s):  
Dhrubajyoti Singha ◽  
Md. Fahad Jubayer ◽  
Kumkum Devnath ◽  
Delara Akhter ◽  
Thottiam Vasudevan Ranganathan ◽  
...  

Aloe Vera leaves have great potential as an economic supplement with an adequate nutritional profile. The current study aimed to fortify plain (loaf) cakes with Aloe Vera leaf gel (AVG) powder. AVG was freeze-dried to produce Aloe Vera powder (ALP), and four plain (loaf) cakes were prepared with different proportions of ALP (0, 4, 6, and 8%). ALP contained significantly (p < 0.05) more protein (22.23 vs. 12.24), ash (19.83 vs. 0.64), and iron (175 vs. 3.05) than refined wheat flour (RWF). Along with total polyphenols and total flavonoids, ALP demonstrated good antioxidant activity. ALP-cakes and RWF-cakes were also evaluated for their nutritional and functional properties. The addition of 6 and 8% ALP to the formulation increased total polyphenols, total flavonoids, and antioxidant activity in plain (loaf) cakes. Hardness and chewiness increased in ALP-cakes but decreased in RWF-cakes, while cohesiveness and springiness decreased in ALP-cakes. In conclusion, the best formulation was a 4% ALP incorporated cake, and ALP can be supplemented in plain cakes at a rate of up to 8% to improve nutrient value. This is the first study to evaluate the quality characteristics of fortified plain (loaf) cakes using ALP.


2005 ◽  
Vol 11 (5) ◽  
pp. 345-352 ◽  
Author(s):  
A. I. Cascales ◽  
E. Costell ◽  
F. Romojaro

Sensory quality of peach during ripening to assess the best state for consumption was analysed. Physical and chemical parameters commonly used for establishing the commercial quality of this fruit were also determined: Soluble solids, acidity, sugars, organic acids, chlorophyll, carotenoids, resistance to compression and to penetration and colour. Relationships among these parameters and sensory characteristics were also analysed. A panel of eight trained assessors evaluated intensities of 12 sensory attributes (1 for odour, 2 for colour, 4 for flavour and 5 for texture). The sensory attributes selected allowed the description of perceivable differences between peaches of different degrees of maturity, although the variation in intensity of the attributes followed different trends. Colour intensity increased and acidity, firmness and crispness decreased significantly with ripening. Intensity of flavour, sweetness and fruitiness increased significantly from the under-ripe to semi-ripe states, and then decreased on reaching ripeness. It can be concluded that the most suitable time for harvesting and consumption of this peach variety was the state described herein as semi-ripe, and that a high correlation existed between colour intensity and hardness and the instrumental measurements of colour and texture.


Revista CERES ◽  
2016 ◽  
Vol 63 (4) ◽  
pp. 436-443 ◽  
Author(s):  
Alice de Souza Silveira ◽  
Aracy Camilla Tardin Pinheiro ◽  
Williams Pinto Marques Ferreira ◽  
Laércio Junio da Silva ◽  
José Luis dos Santos Rufino ◽  
...  

ABSTRACT Specialty coffees can be differentiated in various ways, including the environmental conditions in which they are produced and the sensory composition of the drink. This study aimed to evaluate the effect of altitude, slope exposure and fruit color on the sensory attributes of cafes of the region of Matas de Minas. Sampling points were georeferenced in four altitude ranges (< 700 m; 700 ≤ x ≤ 825 m, 825 < x < 950 m and ≥ 950 m) of the coffee crop; two fruit colors of var. Catuaí (yellow and red); and two slope exposures (North-facing and South-facing). Coffee fruit at the cherry stage were processed and submitted to sensory analysis. The sensory attributes evaluated were overall perception, clean cup, balance, aftertaste, sweetness, acidity, body and flavor, which made up the final score. The scores were examined by ANOVA and means were compared by the Tukey test (p ≤ 0.05). From the sensory standpoint, coffee fruits of both colors are similar, as well as the coffees from both slope exposures when these factors were analyzed separately. However, at higher altitudes, Yellow Catuaí produces coffees with better sensory quality. Similarly, coffees from North-facing slopes, at higher altitudes produce better quality cup. The altitude is the main factor that interferes with coffee quality in the area. All factors together contribute to the final quality of the beverage produced in the region of Matas de Minas.


1970 ◽  
Vol 53 (5) ◽  
pp. 899-902 ◽  
Author(s):  
Barbara R Moorhouse ◽  
Harold Salwin

Abstract Approximately 500 pounds of white shrimp were stored in crushed ice until they decomposed. Portions were withdrawn at intervals and processed. Based on judgments of odor, shrimp that reached a stage of incipient decomposition before processing were rated as passable after they were freeze-dried or cooked. The organoleptic quality of samples that reached a stage of advanced decomposition was also improved by processing, but not to the extent of their being classified as passable. Aerobic plate counts increased during storage but they were reduced significantly by freezedrying or cooking. Although there were changes in composition during storage, the classical chemical tests used were of limited value for assessing the degree of decomposition. Also, many volatile decomposition products were lost during processing. Computing the results of chemical analyses on a moisturefree basis offered distinct advantages. Inasmuch as organoleptic, bacteriological, and chemical tests on the finished products failed to reveal the decomposed condition of the starting material, there is need for additional investigation of methods for that purpose.


2010 ◽  
Vol 1 (3) ◽  
pp. 253-257 ◽  
Author(s):  
C. Simões ◽  
H. Alakomi ◽  
J. Maukonen ◽  
M. Saarela

The aim of the study was to evaluate the potential of utilising the information on expression levels of selected stress genes in assessing the quality of probiotic products. For this purpose RT-qPCR methods were developed to study the expression of clpL1 and clpL2 stress genes in Lactobacillus rhamnosus VTT E-97800 (E800) cells after exposure to processing-related stress conditions or to freeze-drying. Heat treatments in laboratory scale were performed with E800 cells incubated at 47 °C or 50 °C for 60 min. Acid treatments were performed both at laboratory and fermenter scale. At laboratory scale E800 cells were inoculated into General Edible Medium (GEM) adjusted to pH 4.0 and pH 3.5 and incubated at 37 °C for 180 min, whereas fermenter-grown cells were exposed to pH 4.0 for 60 min at the end of the fermentation. RNA from fresh cells and freeze-dried powders was reverse transcribed after isolation, quantification and standardisation. clpL1 and clpL2 transcripts were analysed by RT-qPCR with SYBR Green I. clpL1 was induced in L. rhamnosus E800 cells exposed to 50 °C and to a much lesser extent to 47 °C. No induction was observed for clpL2 in E800 cells during either acid or heat treatment, in any of the conditions applied. RNA isolation from freeze-dried powders was unsuccessful although several attempts were made with high quality products. In conclusion, our results suggest that developing quality indicators for probiotic products based on differences in the expression of stress genes is a challenging task for several reasons: at least with some genes (like in the present study with clpL) quite harsh conditions are needed to detect differences in the gene expression; mRNA isolation from freeze-dried powders was unsuccessful which hampers the quality analysis of large proportion of probiotic products; and furthermore RT-qPCR proved to be a too laborious procedure for routine use.


Author(s):  
Brilliant Margalin ◽  
S. P. Edijanto ◽  
Paulus B. Notopuro

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.


Author(s):  
E.S. Serbis ◽  
I.N., Matveeva ◽  
V. I. Eremets

Тhe aseptic process of industrial production of sterile lyophilized biological products is completed by one of the critical stages of the technological process, the freeze-drying. GOST R ISO 13408-3-2011 defines the term lyophilization as a synonym for the sublimation. Sublimation - the physical process on which the freeze-drying method is based. This paper discusses the issues of freeze drying that engineers and biologists, production technologist, designers of dry preparations, and quality specialists face with. Freeze-drying consists of three stages: freezing, freeze-drying and drying. Each stage has its own critical points, input and output parameters. The task of the developer of freeze-drying technology is to determine the need for each parameter and the sufficiency of their quantity. Equipment, technology and regulatory documents are considered as interdependent elements that make up freeze drying as a system. An integrated approach to the freeze-drying process includes the development of modes, equipment control, and internal documentation. The key parameters of the process are the qualitative and quantitative characteristics (reference values, measurement procedures, acceptable range of values) of the semi-finished liquid product and the finished freeze-dried product. Characteristics of the semi-finished liquid product are the temperature of complete crystallization; upper and lower eutectic temperatures; maximum permissible heating temperature (thermo-lability); density; specific (biological) activity. Freeze-drying process characteristics are: at the freezing stage - reaching the temperature of complete crystallization in the entire volume of the material received for drying; at the sublimation stage - maintaining the temperature in the dried material in the range between the lower and upper eutectic temperatures (without going beyond the upper); at the drying stage - reaching the maximum temperature in the material. The duration of each stage depends on the vial in which the dried material is packed, the volume of packaging, and the features of heat, mass, and energy exchange in the sublimation plant. Standard operating procedures (SOPs) should be designed with these features in mind. For example, for different packages (2ml or 10ml) in vials of the same volume, or for the same packaging in vials of different volumes, for example, 2ml in vial of 10-ml or 20-ml, separate SOPs are required in each case. In the current practice of industrial production, the quality of the lyophilized product is evaluated by humidity (GOST 24061-2012). In our work, to assess the quality of the process, we measured the decrease in the mass of liquid material during drying. We recommend measure both indicators, since they complement each other.


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