
Yasuyuki SagaraIndependent Researcher · R&D Consultant Department
Yasuyuki Sagara
PhD
About
125
Publications
26,336
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
1,362
Citations
Publications
Publications (125)
Advancedtechnologies have been presentedfor optimum freezing andstorage conditions basedon the relationships between ice crystal morphology andfoodqualities such as color andsensory score. An improved methodusing cryo-adhesive film was proposedfor quick measurement of ice crystal size andshape in frozen foods. The formation of ice crystals couldmak...
Cooked rice was frozen in an air blast freezer at freezing temperatures of −5, −10, −15, −30 and −45 °C and stored at −5, −10, −15, −30 and −45 °C for up to 90 days. Cross-sectional images were captured using a fluorescence staining method, and then the equivalent diameters and perimeters of ice crystals were determined. The size and fractal dimens...
Relationships among freezing rate, ice crystal size, and color have been elucidated quantitatively to investigate the whitening effect on the surface of salmon fillet during freezing. Both surface color and ice crystal size, dependent on freezing rate, were measured at the surfaces of frozen gelatin as a model food and salmon fillet. As the ice cry...
This study investigated the influence of mixing and fermentation times on the chemical and physical properties of white pan bread, a typical bread consumed in Japan. Sixteen bread samples were made by combining four dough mixing stages and four dough fermentation times, and were analyzed for compression force, acids, sugars, amino acids, volatile c...
The effects of time and temperature on change in bean colour and kinetics of coffee roasting covering pre-roasting and over-roasting condition were investigated. Arabica coffee beans (Colombia Excelso) were dried or roasted in an oven at constant temperatures (140, 180, 200, 220, 260, and 300 °C) to obtain the profiles of mass loss and colour chang...
Novel methodologies have been developed to predict the values of sensory evaluation score by selecting the combination of measurement methods for grouping viscoelastic parameters, and coupled PLS and ANN modeling have been presented as a quality evaluation model based on the relationship analysis between viscoelastic parameters and sensory scores f...
A quality evaluation model for Cheddar cheeses has been proposed to identify interrelationships among the database of viscoelastic parameters and aroma components obtained from instrumental measurements and both sensory evaluation and palatability scores by utilizing the combination of stepwise PLS-VIP method and ANN modeling. Viscoelastic paramete...
The optimum frozen condition of cooked rice has been predicted by artificial neural network (ANN) based on the data obtained from sensory evaluations as well as viscoelastic measurements. Cooked rice was frozen and stored at -5, -15, and -45 °C for 0, 10, 30, 60 and 90 days. Then, after the samples were thawed by natural convection air at room temp...
A novel technique was developed to recognize ice crystals in biological materials and to analyze their three-dimensional morphology using a Cryogenic Micro-Slicer Spectral Imaging System with a micro-slicer unit and a near-infrared spectral imaging unit. Consecutive cross-sections of a frozen sample were exposed by the multi-slicing operations with...
Optimum temperature conditions of frozen cooked rice during storage have been predicted by artificial neural network (ANN) using the dataset of ice crystal measurement and sensory evaluation. Cooked rice samples were frozen and preserved at -5, -15, -30, and -45°C for 1, 5, 10, 30 and 90 days. Then the cross-sectional images of the samples were cap...
The gluten matrix in bread dough develops through the mixing process, and its microstructure is known to greatly affect the quality of the end product. In this study, a novel method to quantify the gluten matrix was developed by applying image analysis methods used in the area of bone histomorphometry to fluorescence images of dough. Acquisition of...
A consumer-oriented methodological approach for the quality evaluation of Cheddar cheese as a typical fermented food was developed. Datasets were obtained from gas chromatography/olfactometry (GC/O) analysis and sensory evaluation of 10 Cheddar cheese samples. The GC/O analysis identified 43 aroma components under the categories of 14 aroma descrip...
A novel staining procedure has been developed to visualize the gluten-starch matrix in wheat flour dough. Dough samples mixed to the final stage were stained with 26 fluorescent reagents, and each stained sample was observed with three sets of fluorescence filters (blue, green, and red). Of all the combinations of reagents and filters, the combinat...
A binary-phase finite element method (FEM) model was developed to determine the viscoelastic properties of frozen-thawed agar/agar-gelatin gels by treating the tissues as quadrilateral macro columns. The columns of the FEM geometric model consist of the shell grain boundary and a matrix. The mechanical properties of the shell were assumed to remain...
A continuous-flow bubble column reactor for biodiesel production by non-catalytic transesterification of triglycerides has been developed. The principle of a bubble column reactor for transesterification is similar to reactive distillation, where the reaction products in the gas phase are continuously removed from the reactive zone, while oil, as t...
The sampling parameters to simulate retronasal aroma during the mastication of white bread has been optimized using a retronasal aroma simulator (RAS) to compare the retronasal bread aroma with the conventional headspace aroma. The volatile composition in breath was compared with that in the effluent from a RAS using proton transfer reaction mass s...
Micro-Slicer Image Processing System (MSIPS) has been developed for
measuring the three-dimensional(3-D) structure and distribution of ice
crystals formed in biological materials. The system has functions to
reconstruct the 3-D image based on the image data of exposed cross
sections obtained by multi-slicing of a frozen sample with the minimum
thic...
The relationship between the ice polycrystalline structure and the
dielectric properties of a frozen gelatin gel were investigated. The
Micro-Slicer Image Processing System (MSIPS) was applied to measure the
diameter, the perimeter density and the number density of ice crystals.
The dielectric property of frozen gelatin gel at various freezing rate...
To design a consumer-oriented package that complements the taste and aroma of ready-to-drink chilled-cup coffee beverages
by using the food kansei model, the effects of the diameter and the color of drinking straws as well as the cognition terms of coffee on consumer
sensory characteristics and preferences were investigated. Variance and factor ana...
The effect of heating conditions on the crust color formation was investigated during the baking of white bread. The surface temperatures were monitored with thermocouples attached to the inside surface of the loaf pan cover. The trace of the surface color in the L(*)a(*)b(*) color coordinate system is defined as the characteristic coloring curve....
The potent odorants in the crust and crumb of white bread were identified and quantified by gas chromatography-mass spectrometry and gas chromatography/olfactometry. The weight loss ratio of the samples baked at 220 °C was controlled in the range of 0-28%. The odorants were classified into 5 types by the transfer characteristics: i) All amounts of...
Drying Characteristics and the transport properties have been measured
for the dried layers of 9.6-28.8% miso paste undergoing freeze-drying.
Optimum freeze-drying condition was investigated based on the
relationship between the heating temperature and color change by
scorching at the sample surface. The samples were freeze-dried at the
constant su...
A numerical model has been developed for simulating freezing phenomena
of food solution systems. The cell model was simplified to apply to food
solution systems, incorporating with the existence of 3 parts such as
unfrozen, frozen and moving boundary layers. Moreover, the moving rate
of freezing front model was also introduced and calculated by usi...
Micro Slicer Spectral Imaging System (MSSIS) has been applied to observe
the three-dimensional(3-D) structure and distribution of ice crystals
formed in biological materials. MSSIS is composed of a micro-slicer,
near-infrared (NIR) illuminator and spectral imaging system. NIR
Spectroscopic analysis using MSSIS confirmed that there are a water
absor...
A NIR spectral imaging apparatus was developed to obtain information on spectrally discriminated images and the location of material to be measured. The apparatus consisted mainly of a CCD camera, a liquid crystal tunable filter and a spectral illuminator, which consisted of a xenon lump as well as a grating spectrometer. The sample surface image c...
To develop a method for evaluating and designing the retronasal aroma of espresso, sensory evaluation data was correlated with data obtained from gas chromatography/olfactometry (GC/O, CharmAnalysis™) and from an electronic nose system αFOX4000 (E-nose). The volatile compounds of various kinds of espresso (arabica coffee beans from 6 production cou...
The visualization of foreign materials (leaves and stems) in frozen blueberries was achieved by near infrared (NIR) spectral imaging and discriminant analysis. As a preliminary experiment, NIR spectroscopy of a sample surface was carried out to determine the effective wavelengths for differentiating foreign materials from blueberries in the NIR reg...
An investigation for mechanical properties of white bread has been performed by using an uniaxial compression testing machine developed, and the compressibility as well as elastic properties of the crumb have been discussed from the rheological point of view.
For the range of deformation rates up to 25%, a force-deformation curve was found to consi...
Viscoelastic characteristics have been investigated for white bread by means of compressive creep test with special reference to their dependences on storage time and temperature as well as moulding method of dough.
An optimum loading condition for crumb samples was established experimentally, and a four-element mechanical model appeared to be appr...
Experimental study has been carried out on the relationships between breaking characteristics of white bread and its moisture content during storage, considering appropriate conditions for a standard firmness testing method for white bread.
After baking of white bread an uniform distribution of moisture content was observed at the central position...
Rheological study has been carried out on white bread crumb with special reference to baking and storage conditions. The force-compression behavior of the crumb was characterized based on structural changes in solid matrix. The results indicated that the firmness increased with the storage time and changed markedly within 12 hours after baking. A p...
An automatic measurement system was developed to determine the transport properties for food materials. Some mathematical models were developed to determine the thermal conductivity and permeability for the dried layer of food samples undergoing sublimation dehydration. The values of transport properties were presented for several food materials in...
Viscoelasticity and air-bubble parameters were measured to estimate the texture of bread from Sudachi (air-bubble structure) and the relationship was quantified. A sampling size in cross-sectional surfaces of the slices of bread was optimized to quantify relationships between viscoelasticity and air-bubble parameters of bread. As a result, a cubic...
A simple and objective method to measure the bubble structure of bread was developed by using an image scanner and a digital image processing. A bubble-emphasized image was obtained as a result of scanning the sample in four orthogonal directions and min-combining to get the numerical value of the image of the lowest luminance in order to facilitat...
Excitation-Emission matrix (EEM) fluorescence spectroscopy was applied to estimate the mixture rate of the buckwheat flour and the wheat flour, Eleven kinds of mixture of the buckwheat flour and the wheat flour were measured by EEM with excitation wavelength range of 200-900 nm and emission wavelength range of 200-900 nm. PLS regression analysis wa...
The instrumental analytical value and the organoleptic value (n = 576) of 18 representative raw cod roe samples were used to investigate the possibility and the limitation to apply the covariance structure analysis (CSA) as one of the evaluating methods of palatability. Three causal models were obtained as follows : 1) the evaluation of the appeara...
The optimum solution of consumer preference for color tone of commercial fresh cod roe samples has been estimated by applying multivaridate-spline (Kaseda, 2004) and regret function (Takayama et al., 2000) to color parameters [lightness (L*), redness (a*), yellowness (b*), and chroma (C*)]. Sensory evaluation was performed for 18 commercial fresh c...
The effect of the grain boundary of ice crystals in a frozen gelatin solution on the dielectric properties was investigated by the combination of a dielectric spectrometer and image analysis. A micro-slicer image processing system (MSIPS) was applied to measure the grain boundary properties as the perimeter density and number density of ice crystal...
The cross-sectional structure of prawns was directly observed by near infrared (NIR) spectral imaging. We evaluated boiled and non-boiled prawns immersed for 24 h in pure water, as well as in aqueous solutions of sodium chloride and trisodium phosphate (at three concentrations: 0.5%, 1%, and 4%). We used the micro-slicer spectral imaging system com...
A three-dimensional (3-D) bio-imaging technique was developed for visualizing and quantifying the 3-D distribution of yeast in frozen bread dough samples in accordance with the progress of the mixing process of the samples, applying cell-surface engineering to the surfaces of the yeast cells. The fluorescent yeast was recognized as bright spots at...
Cell-surface engineering (Ueda et al., 2000) has been applied to develop a novel technique to visualize yeast in bread dough. Enhanced green fluorescent protein (EGFP) was bonded to the surface of yeast cells, and 0.5% EGFP yeasts were mixed into the dough samples at four different mixing stages. The samples were placed on a cryostat at -30 degrees...
Flavor compounds in white bread have been analyzed by a static-headspace-type GC/MS and sensory evaluation for clarifying the effects of mixing stage and fermentation time on the intensity of flavor compounds as assessed in the crumb and sensory scores of flavor in white bread. Principal component analysis (PCA) and analysis of variance (ANOVA) wer...
A quick (headspace: 1 min and retronasal aroma simulator (RAS): 2 min) sampling method for capturing volatiles released from coffee drinks by solid-phase microextraction (SPME) (fiber type; divinylbenzene (DVB)/carboxen/polydimethylsiloxane (PDMS)) has been applied to freshly brewed espresso and cafd latte (espresso and milk). Headspace volatiles a...
The food kansei model (Ikeda et al., 2004) has been modified to integrate differences in personal attributes between in-house expert sensory assessors and consumer panels for sensory evaluation in the food industry. Three selection tests for expert sensory assessors revealed that the percentage of questions answered correctly on the tests had not s...
Significant physicochemical properties of Danish pastry samples have been identified to establish a methodology for optimally designing product with maximized palatability, using the food kansei model (Ikeda et al., 2004). A series of procedures for textural measurements and analyses has been proposed for the samples, as follows: 1) fixing linear r...
An FEM algorithm was developed to determine the viscoelastic properties of soft tissues of agar/agar-gelatin gels based on the curve-averaged data from stress relaxation experiment of parallel plate compression and FEM optimization technique. This approach enabled more realistic and pertinent expression of the mechanical behavior of the gels than c...
The possibilities and limitations in the food kansei model (Ikeda et al., 2004) have been revealed through a case of product development for a ready-to-eat cup-soup that had achieved two-billion-yen sales in 1993. Based on the pre-specified product concept, twelve samples were selected to extract twenty descriptors for the sensory evaluation of the...
Biodiesel has become more attractive recently because of its environmental benefits and the fact that it is made from renewable resources. Transesterification of vegetable oils with short-chain alcohol has long been a preferred method for producing biodiesel fuel. A new reactor was developed to produce fatty acid methyl esters (FAME) by blowing bub...
This study was intended to build 3D FEM geometry models of actual 'Fuji' apples by digitizing their surfaces, and to determine elastic modulus by FEM simulation based on the F-D curves of radial compression test from a point on apple equator. Also, the general protocol of ASAE S368.4 for predicting the apparent modulus of elasticity and the maximum...
A procedure for determining the viscoelastic properties of apple flesh has been proposed based on compression tests and FEM optimization. Short-term simple compression tests and long-term relaxation tests were performed with cylindrical specimens of apple flesh to measure mechanical properties, and the viscoelastic behavior was predicted using FEM...
The characteristics of biodiesel are similar to diesel fuels, and therefore biodiesel becomes a strong candidate to replace the diesel fuels if the need areses. Biodiesel standard- so called SNI 04-7182-2006 has been approved by the Indonesian National Standardization Agency (BSN). The basic fuel properties for biodiesel are influenced by the fatty...
A novel method of three-dimensionally visualizing the internal structure of a soybean seed, which was based on excitation-emission matrix (EEM) measurement and EEM pattern analysis, was developed. Cross-sectional images of three soybean samples at different germination stages were taken at 561 different excitation and emission wavelength conditions...
A bubble column reactor has been developed to produce fatty acids methyl esters (biodiesel) by blowing superheated methanol continuously into vegetable oils without using any cat alysts at atmospheric pressure. Two types of reactions exist in this method for methyl esters formation; transesterification of triglycerides and esterification of fatty a...
Deregulation policies for the supply chain of agricultural products brought not only a rapid increase in fresh produce that were trensectcd in most of wholesale markets in Indonesia. but also the difficulty in striking an appropriate balance between the expansion of the profit from these transactions and the control of environmental damages in the...
To identify the BOLD effects related to olfaction in humans, we recorded functional magnetic resonance imaging (fMRI) scans in response intravenously instilled thiamine propyl disulfide (TPD) and thiamine tetrahydrofurfuryl disulfide monohydrochloride (TTFD). TPD and TTFD evoked a strong and weak odor sensation, respectively. Since we did not spray...
A conceptual 'food-kansei' model (Ikeda et al., 2004) has been applied to optimize operating conditions of a superheated steam oven prototyped for final food products. Fifteen raw beef samples were heated at the oven temperature of 200-300°C and at the steam injection rate of 3-9kg/h to measure the viscoelastic properties of the roasted samples. Se...
Biodiesel fuel (BDF), biofuel made from natural oils and fats, is being regarded as a promising substitute to the petro-diesel fuel. An alkaline catalyzed alcoholysis process, to form fatty acid methyl esters (FAME) from vegetable oils, is widely used to produce BDF. This process, however, requires high costs for refining the products and recoverin...
As energy dernands increase and fossil fuel reservas are limited, research is directed towards alternative renewable fluls. A potential diesel fuel substitusi is biodiesel, obtained from fatty acids methyl esters (FAME) and produced by the transesterfication reaction of triglyceride or free fatty acid (FFA) of vegetable oils with short-chain alcoho...
Instrumental and sensory analyses were carried out on sesame-flavored dressings to identify the odorants affecting their perceived quality. The sampling of the odor-active compounds was performed by simultaneous steam distillation extraction (SDE) and solid-phase microextraction (SPME). The odor intensity and character of the compounds were evaluat...
Spectral analysis and image processing of the spectral images of blueberries and several foreign substances clarified that plant organs could be detected by the second derivative absorbance image at 680 nm, which is an absorption band of chlorophyll. As a feasibility study, spectral images of blueberries and plant organs placed in the 160 x 120 mm...
To identify the changes in the respective frequency band and brain areas related to olfactory perception, we measured magnetoencephalographic (MEG) signals before and after instilling intravenously thiamine propyl disulfide (TPD) and thiamine tetrahydrofurfuryl disulfide monohydrochloride (TTFD), which evoked a strong and weak sensation of odor, re...
SUMMARY Indonesian national and regional policies on deregulating the supply chain of agricultural products among provinces after the economic crisis in 1997-98, brought a rapid increase in total amounts of fruit and vegetables that were transacted in most of wholesale markets, especially the Kramat Jati central wholesale market in Jakarta. Accordi...
Volatile aroma compounds of freeze-dried soluble coffee were investigated to evaluate the effects of freeze-drying temperature conditions on their intensities and aroma characteristics by employing both GC/MS and charm-analysis, which is a GC/Olfactometry (GC/O) method. The coffee solutions with 40% solid content were freeze-dried changing freezing...
Biodiesel Fuel (BDF), fatty acid methyl ester, is receiving widespread attention for its renewability and carbon neutral property. might be one solution for global environmental problems such as global warming and exhaustion of fossil fuel resources, The material oil of BDF differs in regions, palm oil will be chosen for BDF production in Southeast...
Biodiesel fuel is the colloquial name for fatty acid methyl ester (FAME), Since it has some environmental benefits when used as an alternative diesel fuel, it is becoming more and more popular in the world, especially in Europe and the U. S. Although it can be derived from a wide variety of resources, waste cooking oil is the main fecdstock in Japa...
Measurement of temperature within the products undergoing vacuum cooling is one of the key issues, especially if to be used as a control parameter in the cooling process. Thorough study on temperature distribution during the cooling process is indispensable in order to precisely determine the appropriate location of temperature measurement within t...
In order to evaluate the effect of γ-ray irradiation on starch, near-infrared absorption spectra of four groups of starch samples, control, 10, 20 and 30 kGy irradiated, were measured. By the preliminary analysis, it was revealed that 1 702 and 2 100 nm were effective in predicting the irradiation dose on starch. On the other hand, samples were div...
LCA inventory data based on input-output tables was used to analyze the effects of the self-sufficiency rate of food and the food consumption pattern on the CO2 emission in Japan. For the food item i with the total consumption Ci [M¥] and self-sufficiency rate xi, the total amount of carbon emission consists of (1) domestic production of i, (2) pro...
Ethylene induces premature senescence of orchid flowers when plants are particularly transported with fruits and vegetables stored nearby. Exogeneous ethylene regulated a complex physiological changes of petals in intact flowering clones of Dendrobium phalaenopsis during seven days; decrease in distance between petals, water content, NMR relaxation...
The Food Kansei Model has been developed to formulate the causal relationships between the analyzed characteristics and perceived quality of food products. It was applied to correlate the physicochemical properties with the food perception, preference and pleasantness quantitatively. The model was applied to the practical design of flavor- and tast...
A Micro-Slicer Image Processing System (MSIPS) has been applied to observe the ice crystal structures formed in frozen dilute solutions. Several characteristic parameters were also proposed to investigate the three-dimensional (3-D) morphology and distribution of ice crystals, based on their reconstructed images obtained by multi-slicing a frozen s...
A novel technique has been developed for measuring the three-dimensional (3-D) structure and distribution of ice crystals formed in frozen beef by using a micro-slicer image