Prediction of linolenic and linoleic fatty acids content in flax seeds and flax seeds flours through the use of infrared reflectance spectroscopy and multivariate calibration

Infrared spectroscopy was used for multivariate determination of linoleic (LA) and linolenic (ALA) acids in yellow and brown flax seed samples, using partial least square regression (PLSR). The models were developed by correlating near-(NIR) and mid-infrared (MIR) spectroscopic signals with the acid content determined by GC-FID. For the flax seed samples, the best models for both, LA (R² = 0.90, Standard Error of Prediction (SEP) = 1.61) and ALA (R² = 0.86, SEP = 0.63) were obtained by processing the NIR spectral data. For samples of flax seed flours, the best models for prediction of the ALA (R² = 0.99, SEP = 1.21) and LA content (R² = 0.88, SEP = 0.76) were developed by processing the NIR and MIR spectral region, respectively. This report demonstrates that NIR and MIR spectroscopies are efficient techniques for the determination and quantification of LA and ALA in flax seed and flax seed flours.     

Prediction of fatty acid composition using a NIRS fibre optics probe at two different locations of ham subcutaneous fat

NIR technology was used to analyze the fatty acid composition of fat tissue from conjugated linoleic acid fed pigs by direct application of a fibre optics probe on two different locations of subcutaneous fat. One hundred and fifty-three pigs were fed three different diets and the fatty acid profile of subcutaneous fat from Gluteus medius was analyzed using gas chromatography and FT-NIR in a longitudinal and transversal cut. Spectra were acquired using a Bruker Optics Matrix-F duplex spectrometer equipped with a fibre optics probe (IN-268-2). Total saturated, monounsaturated and polyunsaturated together as well as oleic and stearic fatty acids were predicted accurately (R² > 0.70), myristic, and linoleic fatty acids were predicted with lower accuracy (0.60 < R² < 0.70), while palmitic, asclepic and α-linolenic fatty acids were poorly predicted (R² < 0.60). Results indicated that NIR technology has potential as a rapid tool to discriminate carcasses from animals fed diets with different fatty acid composition by a direct measurement on the fat from the ham.     

Chemical composition and potential of some underutilized tropical biomass. I: fluted pumpkin (telfairia occidentalis)

The seeds of Telfairia occidentalis have been subjected to standard chemical analysis to evaluate their properties. Proximate analysis indicated a low moisture content (6.30 ± 0.50%). The ash content was slightly higher than the range recommended for compounding of animal feed (3.44 ± 0.06%). The carbohydrate content was low (16.5 ± 0.12%). Starch, however, constituted the dominant carbohydrate (62.5 ± 0.48), while three sugars, glucose, fructose and sucrose were detected in the seed. The crude protein in the seed was high (16.0 ± 0.03%), a value which compared favourably with high protein seeds and nuts. In all, 16 amino acids were detected in the protein. Glutamic acid showed the highest concentration (16.4 g 100 g⁻¹), while lysine showed the lowest (2.6 g 100 g⁻¹). The brown oil extracted from the seed (yield 48.6 ± 0.94) had the following physicochemical properties; acid value, 3.05 ± 0.80 g, saponification value 166 ± 1.34 mg/KOH g⁻¹, free fatty acids, 0.3 g and peroxide value 3.02 ± 0.07 mg Eq kg⁻¹. The iodine value (80.1 ± 0.10)g 100 g⁻¹ indicated a preponderance of unsaturated fatty acid. Four fatty acids were detected whilst unsaturated acids constituted 61.3 g. Triglyceride was the dominant lipid species while hydrocarbons, waxes, sterols and sterol esters and higher alcohols, were detected in the unsaponifable matter. Results of nutritionally valuable mineral elements indicated that potassium occurred at the highest concentration.     

Relationship between photon emission and chemopreventive potential of tea

Photon emission from tea (610–670 nm) in the H₂O₂/KHCO₃/MeCHO system and the utility of the photon detection system in tea evaluation were investigated. Photon intensity of tea depended on manufacturing method as follows: green tea (1202 ± SD 173.51 cd/m²) > oolong tea (834 ± SD 237.44 cd/m²) > black tea (222 ± SD 87.65 cd/m²). Photon intensity corresponded with polyphenol content (r²=0.8810) rather than catechin content (r²=0.7759) and showed a high correlation with chemopreventive activities against H₂O₂ (r²=0.7516), O₂⁻ (r²=0.7998) and DPPH radical (r²=0.7516). Photon intensity from green tea leaves at each manufacturing process step gave the same decreasing curve as DPPH radical scavenging activity. Chemiluminescence of tea, which gives information on the polyphenol content and chemopreventive potential, is a useful technique for tea evaluation.     

Production of conjugated linoleic acid enriched milk and dairy products from cows receiving grass silage supplemented with a cereal-based concentrate containing rapeseed oil

Opportunities for the production of milk and dairy products enriched with cis-9, trans-11 conjugated linoleic acid (CLA) were investigated. Eighteen mid-lactation cows were used in a continuous-design for 7 weeks. During the first week, cows received grass silage ad libitum supplemented with 10 kg per day of a cereal-based concentrate (control) that was replaced with a concentrate containing 50 g kg⁻¹ of rapeseed oil (RO). Changes in milk fatty acid composition were monitored on a weekly basis and milk produced was used to manufacture Edam cheese and butter. Inclusion of RO in the concentrate supplement increased the mean levels of trans-octadecanoic, monounsaturated, CLA and polyunsaturated fatty acid in the milk fat from 1.6, 25.7, 0.46 and 2.8 to 4.3, 35.3, 1.02 and 3.9 g 100 g⁻¹ total fatty acids, respectively. In contrast, the mean level of saturated fatty acids decreased from 71.4 to 60.7 g  100 g⁻¹ total fatty acids. Changes in milk fatty acid composition due to RO occurred within 7 days, with responses reaching a plateau after 21 days. Furthermore, the CLA concentrations in the milk fat from individual cows ranged between 0.37 and 0.65 and 0.43 and 2.06 g 100 g⁻¹ total fatty acids for the control and RO diet, respectively. CLA enriched milk was used successfully to manufacture of Edam cheese and butter with softer textures but with acceptable organoleptic and storage properties. Processing milk into butter or cheese had no effect on the CLA concentrations indicating that enrichment of dairy products is dependent on the content in raw milk fat.     

Proximate composition,cholesterol and fatty acids profile of canned sardines (Sardinella brasiliensis) in soybean oil and tomato sauce

Different brands of sardines canned in soybean oil and tomato sauce, that are commercialized in Brazil, had their proximate composition, cholesterol content and fatty acids composition analyzed. Protein contents were equivalent to the values found for sardines in natura, ranging from 19.8 to 24.4%. High variations of the total lipids content (5.30–16.8%) were verified; the highest levels were found for sardines canned in soybean oil. The cholesterol content ranged from 50.4 to 65.1 mg/100 g. The highest levels of essential C18:2n − 6 and C18:3n − 3 fatty acids were found in sardines canned in soybean oil. The EPA (C20:5n − 3) and DHA (C22:6n − 3) concentrations ranged from 5.39 to 15.1% and from 3.89% to 9.51%, respectively, and the highest levels were observed in sardines canned in tomato sauce.     

MRI-based analysis,lipid composition and sensory traits for studying Iberian dry-cured hams from pigs fed with different diets

The present work was aimed to study Iberian dry-cured hams from pigs reared outdoors and either fed with acorns and grass (AG) or with oleic acid enriched concentrates (HO), by means of their fatty acid profile, sensory traits and Magnetic Resonance Imaging (MRI). The level of total saturated fatty acids (SFA) was higher in HO than in AG hams, whereas total monounsaturated (MUFA) and polyunsaturated fatty acids (PUFA) showed higher proportions in AG than in HO Iberian dry-cured hams. Besides, lower levels of the n ? 6/n ? 3 ratio were found in AG than in HO dry-cured hams. Sensory analyses only showed differences between AG and HO Iberian dry-cured hams in pastiness (higher in AG hams, p = 0.039) and marbling (lower in AG hams, p = 0.002). Pig feeding also leads to differences in two computational texture features obtained by MRI-based analysis. Thus, analysis of the fatty acid profile and MRI-based analysis might be used for classifying dry-cured hams from pigs fattened with different diets.     

Soluble phenolics and antioxidant properties of soybean (Glycine max L.) cultivars with varying seed coat colours

This research was the first to investigate nutritional components, including soluble phenolics (isoflavones and anthocyanins), protein, oil, and fatty acid as well as antioxidant activities in different coloured seed coat soybeans (yellow, black, brown, and green) for two crop years. The soluble phenolics differed significantly with cultivars, crop years, and seed coat colours, while protein, oil, and fatty acid exhibited only slight variations. Especially, malonylgenistin and cyanidin-3-O-glucoside compositions had the most remarkable variations. Green soybeans had the highest average isoflavone content (3079.42 μg/g), followed by yellow (2393.41 μg/g), and black soybeans (2373.97 μg/g), with brown soybeans showing the lowest value (1821.82 μg/g). Anthocyanins showed only in black soybeans, with the average contents of the primary anthocyanins, cyanidin-3-O-glucoside, delphinidine-3-O-glucoside, and petunidin-3-O-glucoside, quantified at 11.046, 1.971, and 0.557 mg/g, respectively. Additionally, Nogchae of green soybean and Geomjeongkong 2 of black soybean may be recommended as potential cultivars owing to the highest average isoflavone (4411.10 μg/g) and anthocyanin (21.537 mg/g) contents. The scavenging activities of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radicals also differed remarkably, depending upon isoflavone and anthocyanin contents, with black soybeans exhibiting the highest antioxidant effects.     

Biochemical changes throughout the ripening of a traditional Spanish goat cheese variety (Babia-Laciana)

The physico-chemical characteristics, proteolysis (classical nitrogen fractions, caseins and their degradation products and free amino acids), and lipolysis (fat acidity and free fatty acids) were studied throughout the ripening of three batches of Babia-Laciana cheese, a Spanish traditional variety made from raw goats’ milk. The main compositional characteristics of this cheese at the end of the ripening are its high content of total solids (TS) (78.0±2.4 g 100 g⁻¹ of cheese) and fat (61.1±1.2 g 100 g⁻¹ of TS), the presence of residual lactose (1.6±0.8 g 100 g⁻¹ of TS) and its low content of sodium chloride (1.1±0.7 g 100 g⁻¹ of TS) and ash (2.8±0.5 g 100 g⁻¹ of TS). Its pH values (4.44±0.72) are extraordinarily low. The evolution and final values of the different nitrogen fractions show that this cheese undergoes a very slight proteolysis, a fact which was corroborated when the caseins and their degradation products were quantified: β-casein did not undergo any modification throughout ripening, while only 21% of the α_s-caseins were degraded. Free amino acids content increased by a factor of about 7 throughout ripening, resulting in a high content of γ-amino butyric acid and a low content of glutamic acid at the end of the process. Fat acidity increased very slightly, approximately 4.5 times, during ripening, reaching final values of 3.5±2.2 mg KOH g⁻¹ of fat. The total free fatty acids content showed a similar evolution to fat acidity. At the end of the ripening process, the main free fatty acid was C_18:1, followed by C₁₆ and C₁₀.     

Assessment of the protein quality of fourteen soybean [Glycine max (L.) Merr.] cultivars using amino acid analysis and two-dimensional electrophoresis

The protein quality of commercial soybeans varieties can be determined from their total protein content, their amino acid composition and from the ratio of glycinin to β-conglycinin, the major seed storage protein components. In this study 14 commercial soybean cultivars were assessed. There were significant differences in storage protein composition (P < 0.05) and in their valine, proline and phenylalanine contents (P < 0.01 to P < 0.001). Mean protein values among these varieties ranged from 29.8% to 36.1%. The total amino acid nitrogen (AAN) ranged from 89.6 to 95.1 g AA/16 g of nitrogen, corresponding to nitrogen values from 16.5 to 17.9 g AAN/100 g protein. All varieties contained a good balance of essential amino acids (EAA₉), limited only in methionine. Two-dimensional gel electrophoretic (2-DE) separations, led to the establishment of high-resolution proteome reference maps, enabling polypeptide chain identification and calculation of the ratio of the constituent glycinin and β-conglycinin storage proteins of soybean. This method enables the assessment of the genetic variability of the soybean cultivars, which can then be correlated with their protein quality and food processing properties. These three methods can be used as very effective tools for assisting plant breeders in their selection of high quality soybean varieties.     

Comparison of NIR and MIR spectroscopic methods for determination of individual sugars,organic acids and carotenoids in passion fruit

In this work, NIR and MIR spectroscopy was investigated and compared for predicting passion fruit ripening parameters as sugars, organic acids and carotenoids. Spectra of 56 samples of the lyophilized passion fruit were collected using an integrating sphere in NIR range and attenuated total reflectance accessory in MIR range. Individual sugars (sucrose, glucose and fructose), organic acids (malic and citric acids) and carotenoids (β-carotene) contents were determined by reference methods. Spectral and reference data were analyzed by principal component analysis. Partial least square regression (PLSR) was used to establish calibration models. MIR technique was better than the NIR technique for glucose (R²_v = 0.942), fructose (R²_v = 0.855), sucrose (R²_v = 0.818), total sugar (R²_v = 0.914) and citric acid (R²_v = 0.913) content determination. On the other hand, NIR was superior for total acids (R²_v = 0.903) content determination. For malic acid and β-carotene contents both methods were unsatisfactory due to low concentrations of these constituents in the passion fruits.     

Oil content and fatty acid composition of some underutilized legumes from Nigeria

Three underutilized legumes from Nigeria, Brachystegia eurycoma, Tamarindus indica and Mucuna flagellipes, have been subjected to standard analytical techniques in order to evaluate proximate composition, physicochemical properties and contents of nutritional valuable elements and fatty acids of the seeds and oils. The proximate analysis indicated that the oil content was 5.87 ± 0.30, 7.20 ± 0.45 and 3.77 ± 0.21 g/100 g for B. eurycoma, T. indica and M. flagellipes, respectively. The seeds are rich in protein and carbohydrate, the protein content ranging from 11.82 ± 0.25 g/100 g–24.94 ± 0.18 g/100 g dry matter. These compare favourably with high protein animal sources like oyster, beef, pork and marine fishes. The iodine value of two of the oils place them in the non-drying group of oils, while the composition of all the oils compare well with those of rape seed, sesame, sunflower and groundnut seed oils. This suggests their use as edible oils.Analyses of the oils for fatty acids indicate that the oils contain linoleic acid which is one of the three essential fatty acids. The dominant fatty acids however are linoleic, palmitic, oleic and stearic acids with oleic acid having the highest percentage 24.13–31.50%. Eight nutritional valuable minerals were determined in the seed flours. The seeds are rich in potassium 52.1 mg/100 g–131 mg/100 g. They also contain significant concentration of iron 4.55 mg/100 g–8.20 mg/100 g.     

Evaluation of minor components,sensory characteristics and quality of virgin olive oil by near infrared (NIR) spectroscopy

Chemometric analyses of NIR spectral data (12,500–4000 cm^? 1) combined with analytical and sensory parameters measured in monovarietal Cornicabra virgin olive oils (VOOs) (n = 97) produced in the PDO (Protected Denomination of Origin) “Montes de Toledo” geographic area were used to generate calibration and validation models in order to be able to predict the minor composition of VOO, in particular its phenolic and volatile compounds as well as its organoleptic attributes, and thereby the global quality of the product. Acceptable multivariate algorithms were obtained for VOOs' degree of unsaturation (fatty acid profile) (r = 0.84–0.96), several minor components – in particular hydroxytyrosol derivatives (r = 0.86–0.88) and C6 alcohols (r = 0.69–0.80) – as well as for positive sensory attributes — ‘fruity’ (r = 0.87) and ‘bitter’ (r = 0.85). The results establish that near infrared is a very useful technique that allows rapid screening of VOO samples to estimate their minor composition and sensory characteristics, and thereby their quality and commercial grade. Furthermore, it may give real time information about olive oil composition during processing in order to automatically control technological parameters.     

Enrichment of the conjugated linoleic acid content of bovine milk fat by dry fractionation

This study investigated the effect of fat fractionation on the conjugated linoleic acid (cis-9, trans-11-C_18 : 2) content of bovine milk fat. Anhydrous milk fat was fractionated into hard and soft fractions using controlled cooling and agitation. Fractionation of milk fat pre-melted at 60°C using a temperature programme of 33–10°C and a cooling rate of 0.58°C h⁻¹ yielded a soft fraction containing 63.2% more conjugated linoleic acid (2.22 g 100 g⁻¹ FAME), which was also enriched in polyunsaturated fatty acids and vaccenic acid (trans-11-C_18 : 1) compared with the parent fat. Agitation following fractionation was found to have a negative effect on the conjugated linoleic acid content of the soft fraction. Refractionation of the soft fraction did not increase the yield of conjugated linoleic acid. The conjugated linoleic acid and trans fatty acid content of 26 selected food products ranging in milk fat content from 0 to 100% is reported. Conjugated linoleic acid concentrations ranged from 0 to 16.2 mg g⁻¹ fat and were generally lower than the trans fatty acid content which ranged from 0 to 155.7 mg g⁻¹ fat. Spreads containing vegetable oils contained higher trans fatty acid and lower conjugated linoleic acid contents than milk fat-containing products. This study highlights that a milk fat fraction enriched in conjugated linoleic acid may be achieved by dry fractionation.     

Lipase-catalyzed synthesis and characterization of flaxseed oil-based structured lipids

The biosynthesis of structured lipids (SLs) was carried out by the interesterification of flaxseed oil (FO) and tricaprylin (TC) in an organic solvent medium (OSM), using selected commercial lipases, including Amano DF, Novozym 435, Lipozyme TL-IM and Lipozyme RM-IM. The fatty acyl chains of the synthesized triacylglycerols (TAGs) were identified by atmospheric pressure chemical ionization/mass spectrometric (APCI/MS) analysis, while the fatty acid positional distribution of the MLM- and MML-SLs (M-medium and L-long chain fatty acids) was determined by silver-ion high-performance liquid chromatographic (Ag⁺/HPLC) analysis. The effects of reaction temperature (T_r, 30–50 °C), enzyme concentration (E_c, 0.5–4%, w/v), initial water activity (a_w, 0.05–0.43) and reaction time (R_t, 0–72 h) on the efficiency of the enzymes, were studied. The bioconversion yield (%) of the synthesized MLM- and MML-SLs was monitored under the established reaction parameters for each lipase. The maximum yield of MLM-SLs was obtained in the order, of Novozym 435 > Lipozyme TL-IM > Lipozyme RM-IM > Amano DF. Moreover, considering the ratio of the MLM- to MML-SLs produced by each enzyme, Novozym 435 and Lipozyme TL-IM were selected as the most effective enzymes for interesterification of FO and TC.     

Effects of geographical origin,variety and farming system on the chemical markers and in vitro antioxidant capacity of Brazilian purple grape juices

The effects of farming system, geographical origin, and grape variety on the in vitro antioxidant capacity, some physicochemical properties and chemical composition were investigated. Major and minor phenolic compounds, reducing and antioxidant assays using chemical and biological systems were determined in n = 62 100% purple grape Brazilian juices (Vitis labrusca L.) from organic and conventional systems from the three largest producing regions. Results were subjected to ANOVA, MANOVA, and principal component analysis. No distinction was observed between organic and conventional grape juices regarding the in vitro antioxidant/reducing capacities, but only through the analysis of individual phenolic acids. The geographical origin and grape variety played a more important role in distinguishing Brazilian grape juices according to the antioxidant activity and some chemical markers. MANOVA was applied and the combined effect of farming system and geographical origin was only significant for tonality (p = 0.044) and protocatechuic acid content (p = 0.030). Correlation analysis was performed and results showed that total phenolic content, total flavonoids, flavonols, anthocyanins, and condensed tannins were statistically associated (p < 0.05) with FRAP, ABTS, and reducing potential of the hydrophilic phenolic compounds (RPHPC). Ascorbic acid did not seem to be involved in the antioxidant potential of the selected purple grape juices. Protocatechuic acid was statistically correlated to FRAP (r = 0.4636, p < 0.001), ABTS (r = 0.3298, p = 0.010), and RPHPC (r = 0.3623, p = 0.004), while ferulic acid correlated with FRAP (r = 0.3410, p = 0.008) and RPHPC (r = 0.2662, p = 0.040). The inhibition of lipid peroxidation conducted at 37 °C in a biological system buffered at pH 7.4 was significantly (p < 0.05) correlated to RPHPC (r = 0.533, p = 0.013) and to the scavenging activity toward ABTS radical (r = 0.505, p = 0.020). In addition, principal component analysis revealed that the inhibition of lipid peroxidation was associated with higher contents of total phenolic content, flavonoids, anthocyanins, flavonols, condensed tannins, and protocatechuic acid. Additionally, both spectrophotometric and chromatographic data regarding the phenolic composition seemed to be suitable approaches to differentiate Brazilian organic and conventionally-produced purple grape juices using PLS-DA as the classification efficiency in the calibration and validation steps were 78% and 75%, respectively.     

Glycine max (L.) Merr., Vigna radiata L. and Medicago sativa L. sprouts: A natural source of bioactive compounds

The consumption of sprouts, common in Asia, has been growing in western countries, once they are a natural healthy food and considered as a valuable dietary supplement. Comparing with their mature counterparts, sprouts are usually richer in health-promoting phytochemicals. So, the nutritional composition and the biological potential of widely consumed sprouts of three species – Glycine max (L.) Merr., Vigna radiata L. and Medicago sativa L. – were compared for the first time. Phenolic compounds and phytosterols were analyzed by HPLC–DAD and organic acids by HPLC–UV. The volatile profile was determined by HS-SPME/GC–IT/MS. Fourteen phenolic compounds (including four isoflavones), three sterols one triterpene, sixteen fatty acids, seven organic acids and thirty volatile compounds were determined. The antioxidant activity was assessed against DPPH^?, superoxide and nitric oxide radicals. G. max sprouts were the most active against DPPH^? (IC₅₀ = 1.337 mg/mL), while those of M. sativa were the most effective against superoxide and nitric oxide radicals (IC₅₀ = 67 μg/mL and IC₅₀ = 426 μg/mL, respectively). Data provide evidence of great similarities between G. max and M. sativa sprouts, both being rich in phenolic compounds, fatty acids and volatiles, and exhibiting better antioxidant activity. On the other hand, V. radiata showed higher amounts of sterols, triterpenes and organic acids. In this study it was found that the sprouts are a good source of bioactive compounds in our diet with health-promoting antioxidants.     

Contribution of coagulant and native microflora to the volatile-free fatty acid profile of an artisanal cheese

The contributions of the coagulant Cynara cardunculus and of the microflora of raw milk to the volatile-free fatty acid profile of Serra da Estrela cheese were evaluated. The experimental design included both a model system and, dual cheeses. The study in the model system showed that isovaleric acid was the predominant volatile compound after 7 d of ripening. The systems inoculated with Enterococcus faecium produced the highest amount of this volatile (ca. 135.8 mg kg⁻¹ curd), while those inoculated with Lactobacillus plantarum produced the least (21.4 mg kg⁻¹ curd); Lactococcus lactis produced moderate amounts (ca. 34.2 mg kg⁻¹ curd) but a total amount of volatile-free fatty acids similar to those found in control samples. This is considered advantageous since this volatile fatty acid confers a harsh, piquant, mature flavour to cheese, coupled with the realisation that excess volatiles may result in off-flavours. The addition of cultures in experimental cheeses helped reduce ripening time to about one half. Inclusion of Lb. plantarum led to cheeses containing the highest amounts of volatiles, and exhibiting an aroma closest to that of typical Serra da Estrela cheese.     

Changing soybean isoflavone composition and concentrations under two different storage conditions over three years

Soybean in Asia have been consumed in various forms, including soymilk, tofu and fermented products such as miso, temph and sufu. It is popularly regarded as a healthy food, partly owing to the isoflavones contained in their seeds. The objective of this study was to evaluate the variation of isoflavone concentration in soybean (Glycine max (L.) Merrill) seeds under different storage conditions for long storage periods. Isoflavone concentrations varied from 699.7 to 2581.6 μg g⁻¹ with cropping year, and acetylglucoside groups and glycitein were only detected in small amounts or traces in the eight soybean cultivars. The Daweon cultivar showed a variation between storage at room (−2039.0 μg g⁻¹) and low temperature (−1822.0 μg g⁻¹) over three years, while the isoflavone concentration in the Hannam cultivar only varied slightly (room temperature: −91.6 μg g⁻¹, low temperature: −81.2 μg g⁻¹). With storage at room temperature, the acetylglucoside group (+7.2 μg g⁻¹) slightly increased the isoflavone concentration, while the other three groups decreased it. In particular, the malonylglucoside group (−519.0 μg g⁻¹) showed a severe decrease. In the Myeongjunamul cultivar, genistin (+105.0 μg g⁻¹) resulted in the highest increase, while malonylgenistin (−958.7 μg g⁻¹) resulted in the greatest decrease in the Daweon cultivar. With storage at low temperature, other than malonylglucoside (−438.1 g g⁻¹), the other three groups, aglycon (+11.4 μg g⁻¹), glucoside (+45.2 μg g⁻¹) and acetylglucoside (+12.8 μg g⁻¹), increased the isoflavone concentration. Genistin (+136.0 μg g⁻¹) in the Muhan cultivar showed the highest increase, and malonylgenistin (−833.4 μg g⁻¹) in the Daweon cultivar showed the greatest decrease for storage under low temperature for three years. The variation of isoflavone concentration was positively correlated with the two different storage conditions (r² = 0.33), and total isoflavones were correlated with the concentration of the malonylglucoside (r² = 0.88***) and glucoside (r² = 0.80***) groups. Our study suggests that it may be feasible to improve the preservation method of soybean isoflavones as high functional substances for longer storage periods.