NUTRITIONAL, PHYSICOCHEMICAL STABILITY, MICROBIAL SURVIVABILITY AND SENSORIAL EVALUATION OF LEGUME YOGURTS

, and Bifidobacterium longum ), followed by fermentation at 37°C until they reached pH 4.5. Legume yogurts were analyzed for their chemical compositions, amino acid content, and sensory evaluation. Changes in pH, titratable acidity, color, water holding capacity (WHC), rheological properties, and microbial survivability were also evaluated during storage at 4°C for 28 days. Total solid (≥11.63%), moisture (≥81.44%), and protein (1.62 to 5.12%) contents were recorded, while glutamic acid, aspartic acid, and lysine were the most prevalent amino acids detected in the legume yogurts. During storage, the pH significantly decreased (P>0.05) while the titratable acidity increased. The legume yogurts showed shear-thinning properties (n<1) with reduced WHC during storage. The lactic acid bacteria survivability remained ≥7 log cfu/ml until the end of storage, except for B. longum . Desirable consistency, sweetness, and sourness were obtained from the sensorial evaluation. However, there was also an unfamiliar taste that developed from the products which affected their overall acceptability. In conclusion, legumes are great lactic acid bacteria carrier and their utilization provide a promising alternative for dairy substitutes.

USA) for 3 minutes. The resulting slurry was filtered by muslin cloth, and the liquid phase produced was referred to as legume milk.

Preparation of legume yogurt
Legume yogurts were produced from flour and milk of soybean, mung bean, and pigeon pea as the main ingredient. Both ingredients required different amount of legume contents due to their least gelation properties, where the values were 8% (w/w) and 16% (w/w) for legume flour-based yogurts and legume milk-based yogurts, respectively. All legume yogurt managed to show yogurt-like consistency although lesser legume contents were used in legume flour-based yogurts than legume milk-based yogurts. In addition, fixing the legume contents to 16% (w/w) in both ingredients resulted in paste-like consistency in legume flour-based yogurt due to the presence of insoluble carbohydrate and protein in the legume composition. Initially, legume flours (8% w/w) were incorporated with deionized water (83.5% w/w) and mixed to form suspension. Meanwhile, legume milks (91.5% w/w) containing 16% w/w of legume flour can be readily used to produce yogurts. Legume flour suspensions and legume milks were heated under continuous stirring until 60°C. Sugar (7.5% w/w) and xanthan gum (0.5% w/w) were added followed by homogenization (IKA T25, Ultra-Turrax, USA) at 5000 rpm for 3 minutes. The mixtures were further heated at 95°C for another 15 minutes for pasteurization and gelatinization processes. Prior to starter culture inoculation (0.5% w/w), the mixtures were let to cool to approximately 40°C. The fermentation process was carried out at 37°C until they reached pH 4.5. Yogurts produced were refrigerated at 4°C until further analyses. Control yogurt was prepared from full fat soybean to mimic the commercial soy yogurt production as prepared by Ferragut et al. (2009) with slight modification. The beans were soaked with water at ratio 1:2 (soybean: water) for 14 hours. The water used was discarded and milk was obtained by blending the hydrated beans (16% w/w) with water (84% w/w), followed by filtration via muslin cloth. Control yogurt was prepared accordingly to the same methods described before. The flow process for yogurts production was illustrated in Figure 1.

Chemical composition
Legume seeds and legume yogurts were analyzed for moisture, total solids, ash, fat and protein based on method of AOAC (2005) at Day 0 of storage. Moisture content and total solid were determined by drying the samples in an oven at 105°C until constant weight achieved. Ash content was obtained by heating the residues at 550°C using muffle furnace. Gerber method was used to evaluate the fat content in legume yogurts, while Soxhlet was used to determine fat content in legume seeds. Kjedahl method was used to determine crude protein (conversion factor: 6.25).

Amino acid profiling
The amino acid profile of the samples was determined based on method described by Goh et al. (2017) with some modifications. Legume yogurts were measured (0.2g), added to 5 ml 6N HCl and heated at 110°C for 24 hours for hydrolysate process. The internal standard (2.5 mM L-2-aminobutyric acid, AABA) (4 ml) was added into the samples and further diluted with water in 100 ml volumetric flask. The diluted samples (1.5 ml) were filtered through 0.45 µm PTFE syringe filter.
Derivatization process was carried out by mixing 70 µl borate buffer (AccQ Fluor Borate Buffer) and 10 µl of filtered samples. Then, 20 µl AccQ Fluor reagent was added prior heating at 55°C for 10 minutes. The samples were injected (10 µl) while the column was kept at 36°C. AccQ tag column (3.9 x 150 mm) on HPLC system (Waters, Model Alliance e2695, Massachusetts, USA) with fluorescence detector (Waters, Model 2475, Massachusetts, USA) with Ex = 250 nm, Em = 395 nm was used to separate the amino acid contains in the samples. The mobile phases consist of eluent A (AccQ Tag Eluent A: deionized water, 1:10), eluent B (acetonitrile) and eluent C (water) was injected at a flow rate of 1 ml/min throughout the analysis. The amino acids contents in the samples were presented in g/100g.

Determination of pH and titratable acidity
The pH values were measured using pH meter (Mettler Toledo, Switzerland) at room temperature (24°C). Titratable acidity was determined on 9 g of samples diluted with distilled water (18 g), and subsequent titration with 0.1N NaOH using 0.1% phenolphthalein as indicator. The volume of NaOH used was recorded when the pH reached 8.3. The results were expressed as lactic acid percentage following this equation: Titratable acidity (% lactic acid) = Volume of 0.1N NaOH × 0.009 Weight of sample × 100

Water holding capacity
The water holding capacity was determined as described by Ferragut et al. (2009) with slight modifications. The samples were weighted (30 g) and inserted in 50 ml polypropylene centrifuge tubes, followed by centrifugation at 480 g for 10 min at 4°C to obtain the expelled whey. WHC was calculated according to the following equation.
Water Holding Capacity (%) = (Weight of sample − Weight of whey) Weight of sample × 100

Rheological properties
Rheological properties were determined based on method by Hickisch et al. (2016) with little modification using rheometer (Haake RheoStress 6000, USA) equipped with 35 mm parallel serrated plates (PP35 Ti L S), and gap setting of 1 mm at controlled temperature (4°C). Samples were gently stirred for 10 seconds before carefully placed in the inset plate and left rest for 5 minutes. Flow curves were obtained through upward (0 to 300 s -1 ) and downward (300 to 0 s -1 ) flow shear rate at a linear ramp within 3 minutes for each flow. The apparent viscosity with shear rate of 50 s -1 was calculated with Rheowin software (ThermoHaake GmbH,). Herschel-Bulkley model was used to generate flow behavior parameters following this equation: where is the shear stress, is the yield stress, K is the consistency index, n is the behavior index and is the shear rate. The viscoelasticity properties of samples were determined by frequency sweep test from 0.1 Hz to 10 Hz at constant shear strain of 0.5%. Measurements were conducted within the linear viscoelastic range, previously determined by amplitude sweep test from 0 to 50% strain at 1 Hz (Yang et al., 2012). Storage modulus (G'), loss modulus (G'') and tan were calculated with Rheowin software (ThermoHaake GmbH).

Sensory evaluation
The commercial soy yogurt (Kingland, Australia) was used as a commercial sample. Fifty untrained panelists were invited to evaluate the legume yogurts using a 9-point hedonic scale, ranging from extremely dislike (1) to extremely like (9). They were served at 7-10 °C in paper cups and were coded with three-digit numbers. Blueberry filling was added to each sample cup before serving to mimic the commercial yogurt used in this evaluation and mineral water was also provided to cleanse the mouth between testing. The test comprising 8 attributes namely, aroma, flavor, consistency, sweetness, astringency, sourness, aftertaste and overall acceptance were used to determine consumers preferences on the legume yogurts prepared (Zare et al., 2011).

Statistical analysis
The significant differences of the mean values (n = 3) were analyzed by two-way ANOVA followed by Tukey's HSD posthoc test (p < 0.05) using Minitab 17 (Minitab Inc., State College, PA, USA). All data were presented as mean value ± standard deviation.

Chemical composition of legume flours and yogurts
The chemical compositions of legume flours and legume yogurts were presented in Table 1 and Table 2, respectively. The moisture contents of defatted flours (defatted soybean flour (DSBF), defatted pigeon pea flour (DPPF) and defatted mung bean flour(DMBF)) were lower (P<0.05) than whole soybean flour (WSBF) due to the overnight drying process to remove the remaining solvent used during defatting process. Meanwhile, there were variations in the protein, ash and fat values recorded by the legume flours which ranged between 19.35% to 40.21%, 3.31% to 5.33% and 0.96% to 21.72%, respectively. DSBF had the highest protein and ash contents, where the values were significantly different (P<0.05) from other legume flours. Besides, fat removal had increased the relative proportion of protein and ash in DSFB as compared to WSBF. The variation inchemical compositions among type of legume flours are largely attributed by their genetics, varieties and growth environment (Kaur and Sigh, 2007). It is crucial to remove the fat to obtain a more concentrated protein content in the flours which helps in improving the flours' functionality. Besides, elimination of fat provides the flours better stability because it removed the possibility of fat hydrolysis and oxidative rancidity.  In Table 2, the moisture (81.44% -88.37%) and solid contents (11.63% -18.56%) of all legume yogurts except for control yogurt (CY) (P<0.05) were comparable with other findings, indicating that the typical ranges of yogurts are between 80% and 85% and 12% to 15% w/v, respectively (Rinaldoni et al., 2012; Santillán-Urquiza et al., 2017). Weak gel-like texture was observed in CY due to its low solid content (11.63%). This indicated that solid content in yogurt formulation is crucial to form stable structures with adequate viscosity (Rinaldoni et al., 2012). Besides, legume yogurts from legumes milk formulation (soybean milk yogurt (SBMY), pigeon pea milk yogurt (PPMY), mung bean milk yogurt (MBMY)) had higher total solids and protein contents than legume flours formulation of similar legume varieties (soybean flour yogurt (SBFY), pigeon pea flour yogurt (PPFY), and mung bean flour yogurt (MBFY)). These happened due to differences in legume concentrations (8% and 16%) used in both formulations. Legume milk yogurt formulation required higher legume concentration to imitate gel-like consistency of yogurt, while legume flour formulation able to form similar consistency with lesser legume concentration. The ability to form gel like texture at different concentration can be linked to their least gelation properties. Generally, the expected chemical compositions of legume yogurt can be calculated based on the legume flour chemical compositions presented in Table 1. The protein content in CY was lower than its expected values (4.88%). It can be due to leaching of chemical components into soaking medium prior to yogurt production (Ogundipe et al., 2021). Similar trend was observed on legume milk yogurts formulation, where the values of protein contents were slightly lower than their expected amounts (3.10% -6.43%). Some of the residues that were trapped on the muslin cloth during filtration process contained insoluble materials that affected the chemical composition of the legume milks. Meanwhile, incorporation of legume flour in legume flour yogurt formulation gave higher protein values than their expected values (1.55% -3.22%). Intense proteolytic activity during fermentation process helps to increase the protein contents in the yogurts. Similar observation was recorded by Lim et al. (2019) when legume-based yogurt was prepared using water kefir as starter culture. In addition, the protein contents of legume yogurts varied between 1.62% to 5.12%, where the value in SBMY was significantly higher (P<0.05) compared to the others. Based on Tiwari et al. (2011), soybean has high protein content (35% -43%). Thus, having higher amounts of soybean in the formulation will contribute to higher protein content per gram of flour in contrast to pigeon pea and mung bean flours. CY had the highest fat content (2.61%) (P<0.05) among all the legume yogurts (<0.89%) as whole fat bean was used to prepare the CY, while others had gone through defatted process prior to utilization into yogurt production. The ash contents (0.27% -0.64%) for all legume yogurts were in accordance with values reported in sprouted cereals probiotic drinks (

Amino acids content
The amino acids contents of legume yogurts were depicted in Table 3. Glutamic acid, aspartic acid and lysine were the main amino acids found in all legume yogurts, ranging from 0.237 to 0.620 g/100g, 0.140 to 0.413 g/100g and 0.105 to 0.289 g/100g, respectively. Sulphur-containing amino acids such as methionine and cysteine are limited, whereas cysteine was only detected in MBFY (0.059 g/100g) and MBMY (0.183 g/100g). Similarly, yogurt produced from Lupinus campestris seeds also had inadequate sulphur-containing amino acids . The total amino acids present in legume yogurts were from 1.121 g/100g to 3.057 g/100g. Low total amino acids content in CY may be due to loss of soluble proteins and amino acids during soaking process of whole fat soybean prior to yogurt preparation. This observation was in accordance with de Lima et al. (2014), and showed that soaking treatment had led to leaching of water-soluble compounds (protein, carbohydrates and others) in soybean.

pH and titratable acidity
Figures 2A and 2B show changes in pH and titratable acidity of legume yogurts during 28 days of storage, respectively. The acidity in the legume yogurts were determined based on pH and titratable acidity, which the latter was expressed as lactic acid percentage. Lactic acid is produced as primary metabolite on proliferation of lactic acid bacteria during fermentation process, thus resulting in pH reduction in the legume yogurt cultures. In this study, the incubation process was stopped once the legume yogurts reached pH 4.5 ( Figure 2A). However, lactic acid percentages (Day 0) differed significantly (P<0.05), ranging between 0.40% and 0.92% ( Figure 2B). Besides, the result showed that legume yogurts from milk legume formulation had higher lactic acid percentage than their respective legume yogurts from flour legume formulation, and followed this sequence: SBMY > MBMY > PPMY > SBFY > PPFY > CY > MBFY. Reduction of pH in legume yogurts once fermentation ended had shown that all legume substrates used in this study managed to support the growth of lactic acid bacteria with sufficient amount of potentially vital nutrients without dairy-based ingredients (lactose, whey protein and sodium caseinate) supplementation. Type of legumes and formulations had different ability to stimulate lactic acid production in the cultures, thus suggesting wide variations of lactic acid percentages in legume yogurts. This trend can be linked to acid-buffering capacity (also referred as buffering capacity) of legumes. The buffering capacity is positively influenced by solid and protein content of food formulation, particularly with high amount of glutamic acid and aspartic acid (Kizzie-Hayford et al., 2016). High buffering capacity in SBMY, MBMY and PPMY resulted in low acidification rate. Therefore, they required longer time to reach pH 4.5 and provide more incubation time for lactic acid bacteria proliferation which led to higher lactic acid percentage. Previous study by Almnura and Arabia (2011) also found that buffering capacity in different sesame yogurt formulations had affected the titratable acidity values (0.52% -1.00%) after 8 hours of fermentation process.

Color
The changes in color parameters (L*, a* and b*) in legume yogurts were shown in Table 4. On Day 0, the L*, a* and b* values ranged from 68.26 to 77.07, -0.90 to 4.64 and 14.38 to 27.44, respectively. The L* values of legume yogurts were highly influenced by their type of legume used compared to their formulation, where yogurts from pigeon pea (PPFY and PPMY) had higher L* than soybean (SBFY and SBMY) and mung bean (MBFY and MBMY) . CY had the highest L*, suggesting that CY had better gel homogeneityity that provided better light reflection on the gel surface than other legume yogurts. The L* values recorded in legume yogurts were higher than L* of yogurt-like product from marble variety of Africa yam bean (

Water holding capacity
Water holding capacity (WHC) of legume yogurts throughout 28 days of storage were depicted in Figure 3. During Day 0, the WHC of legume yogurts ranged between 46% and 100%, where MBFY and CY had the maximum and minimum ability to hold water in the matrix, respectively. Protein is an important component that helps to strenghten the microstructure network in yogurt and consequently improved the WHC by entraping water within its three-dimensional network (Yang and Li, 2010). However, legume yogurts from soybean (SBFY and SBMY) had lower WHC than mung bean (MBFY and MBMY) and pigeon pea (PPFY and PPMY) despite having higher protein content than others. Therefore, we suggested that starch and other carbohydrate components (hemicellulose and fiber) may help to enhance WHC in MBFY, MBMY, PPFY and PPMY as pigeon pea and mung bean had high amount of these components.    et al., 2016). Presence of starch in legume yogurts can induce retrogradation upon cooling which lead to water expulsion from gel, and resulted in reduced WHC during storage (Vaz Patto et al., 2015). Degree of retrogradation in legume yogurts might vary depending on the amylose/amylopectin ratio and starch concentration of the legume used. Besides, extensive storage time can initiate water loss in the food system due to passive diffusion (Cruz et al., 2007). This suggests that similar process could have happened in legume yogurts as clear phase separation was observed at the end of the storage study.

Rheological properties
Flow curves of legume yogurts were described by Herschel-Bulkley model (Table  5)  yogurts firmness and this is due to the presence of crosslinked structure in the food system (Yang et al., 2012).  (Yang et al., 2012).
Similarly, shear thinning behavior were also reported in other fermented products such as lupin yogurt (Hickisch et al., 2016) and germinated soy yogurt (Yang et  al., 2012). Meanwhile, the apparent viscosity of legume yogurts on upward flow curves were higher than their respective downward flow curves due to limited structure rebuilding time after applying continuous shear rate. As expected, higher apparent viscosity were also observed in MBFY and MBMY samples compared to other legume yogurts. According to Akin and Ozcan (2017), viscosity can be influenced by the changes of protein matrix density inside the microstructure at different rates of plant proteins. Presence of starch in legume yogurts formulations also helps to strenghten gel network, contributing to gelation (Masiá et al., 2021).
Thus, composition of protein and starch in mung bean had demonstrated stable and rigid gel structure with suitable rheological properties for legume yogurts development compared to other type of legumes used in this study. The extend and strength of legume yogurts internal structure during storage can be described by the viscoelastic properties (Figure 4). The G' (Figure 4A and 4C) values in legume yogurts were continuously higher than G'' ( Figure 4B and 4D) with varied viscoelasticity intensity (P<0.05) between samples on Day 0 and Day 28, respectively. This result showed a predominantly elastic behavior (G' > G'') among legume yogurts. Besides, the values of G' and G'' in legume yogurts formulated with flour (MBFY and PPFY) were higher compared to CY and milk formulation (MBMY and PPMY), except in soybean (SBFY and SBMY). High G' is influenced by better protein-protein interaction which happened after protein rearrangement (Doleyres et al., 2005). There is also a possible proteincarbohydrate interaction in the system, especially in legume flours formulation that help to strengthen gel network (Sendra et al., 2010). Furthermore, tan corresponded to G''/G' and the value closer to 0 represent more-solid like behavior. Tan values for the legume yogurts on Day 0 and Day 28 ranged from 0.13 to 0.76 and 0.10 to 0.75, respectively (Table 5), confirming that solid-like properties predominated over liquid-like properties.

Microbials survivability
The common starter culture used in commercial yogurt contained the combination of S. thermophilus and L. bulgaricus (Granato et al., 2010). In recent years, incorporation of probiotics bacteria from Lactobacillus and Bifidobacterium species together with starter culture has gained so much interest to further exert overall health benefits to consumers, especially the gut system. An appropriate amount of viable probiotics is necessary to ensure continuing positive well-being upon consumption and it is recommended to be between 6 -10 log cfu/ml (Martins et al., 2013). Thus, selective enumeration of S. thermophilus, Lactobacillus sp. and B. longum in legume yogurts were done throughout the 28 days of storage (Table 6). In this study, Day 0 is defined as the time legume yogurts reached pH 4.5 after incubation process. On Day 0, viable cell counts of S. thermophilus and Lactobacillus sp. in all legume yogurts were between 7.96 log cfu/ml to 8.67 log cfu/ml and 8.21 log cfu/ml to 8.91 log cfu/ml, respectively, while B. Longum's viability ranged from 4.97 log cfu/ml to 5.29 log cfu/ml. Higher viability of S. thermophilus and Lactobacillus sp. than B. longum in legume yogurts were attributed by the differences in initial count of bacteria before inoculation, where the amount of B. longum (~4.00 log cfu/ml) was much lower than the others (~6.00 log cfu/ml) (data not shown). Nutrient competition among bacteria and low substrate suitability of B. longum in legume yogurts might also contribute to this result. This finding is in agreement with previous studies which suggested that excellent growth performance and high cell viability in yogurt culture can be obtained by using high concentration of probiotics inoculation (> 7 log cfu/ml)  ., 2016). Although there were slight deviation of bacteria enumeration in legume yogurts throughout the storage, the differences were possible and can be considered as microbiologically insignificant as the deviations were below 0.5 log cfu/ml (Bedani et al., 2014).  However, the viability of B. longum in all legume yogurts can only be detected on Day 0 and the amount was below the detection limits after Day 7 and onwards. This finding suggested that B. longum has low stability and susceptibility towards legumes as the substrate. Lack of sulphur-containing amino acids in legumes can negatively influence the viability because Bifidobacterium species require considerable amount of these amino acids to support its population during growth and storage (Shi et al., 2020). Besides, B. longum is stricly anaerobe bacteria, and presence of oxygen in the legume yogurt packaging during storage would cause detrimental effect to its survival (Arboleya et al., 2016). Additionally, presence of mold, yeast and coliform were below the detection levels in the legume yogurts,indicating no contamination had occurred and the samples were stored properly throughout the storage (data not shown).

Sensory evaluation
The sensorial attributes of legume yogurts including color, viscosity, aroma, sweetness, sourness, astringency, aftertaste and overall acceptance are presented in Figure 5. During sensory evaluation, control yogurt was replaced with commercially available yogurt (Kingland, Australia) to evaluate and compare different sensorial attributes of legume yogurts. The commercial yogurt provides a better indicator on consumers acceptance of legume yogurts. Commercial soy yogurt obtained significantly higher score (8.18) on color attribute, followed by MBMY (6.12), SBMY (4.72), PPMY (4.52), SBFY (4.56), PPFY (4.48) and MBFY (4.42), respectively. Consumers were more familiar with the silky white color exhibited by commercial yogurt and thus gained better score, while light yellow and slight greenish color on the legume yogurts were perceived as lower visual quality. Commercial yogurt had 'moderately like' score (8) and the score was significantly different (P<0.05) from legume yogurts. Legume yogurts formulation from MBMY and PPMY were assumed to have desirable consistency as they received scores of over 5. While, the 'slightly dislike' score (4) obtained by SBFY, PPFY and MBFY could be due to the presence of lumpy and gritty material from the inhomogeneous texture of the samples. The fermentation process of legume yogurts will produce volatile organic compounds that may influence their aroma release (Coda et al., 2011). From the results, commercial yogurt scored 7.6 ('slightly like') (P<0.05) and PPFY was in 'neither like nor dislike' score (5). Meanwhile, aroma attributes for SBFY, SBMY, PPMY, MBFY and MBMY had below average scores, indicating low acceptance by the panelists due to the undesirable volatile compounds produced. Based on Kaczmarska et al. (2018), green, beany and grassy odors of lupin and soybean are based on the production of hexanal, (E)-2-hexenal, 2-pentyfuran, 1-hexanol and 1-heptanol that will contribute to rancid and off flavors if present in high concentrations. Similar compounds could be present in legume yogurts since off flavors were detected during the sensory test. However, further studies are needed to verify the findings. Taste is a crucial key factor that determines the success of products. In all cases, the commercial yogurt had the highest score in sweetness (6.7), sourness (6.9), astringency (6.4) and aftertaste (6.7) attributes where the values were significantly different (P<0.05) from legume yogurts. MBFY had recorded the lowest acceptability values in all taste attributes, but they are not significantly different (P>0.05) among the legume yogurts. Addition of blueberry filling in legume yogurts were found to be insufficient to mask the unfavorable taste perceived by the panelists.A higher concentration of blueberry filling may be required in the samples. There were also great significant difference (P<0.05) in the overall acceptance between commercial yogurt (7.24) and legume yogurts (3.34 -4.38). This study found that local consumers were not familiar with plant-based yogurt taste and this type of products were uncommon in the market. However, the impact of regular dairy yogurt consumption by consumers had resulted in diverse acceptability and perceptions on legume yogurts. Therefore, preference ratings of legume yogurts can be enhanced by increasing the exposure frequency through product awareness campaigns (Stein et al., 2003). In addition, repeated exposure helps to enhance familiarity to off flavors perception, which consequently influences consumer attitudes in a positive way including increase willingness to consume the products (Granato et al., 2010).

CONCLUSION
Legume yogurts produced from different formulations (flours and milks) and legume varieties (soybean, pigeon pea and mung bean) had shown promising utilization as fermented dairy alternative with great probiotic bacteria viability during storage (> 7 log cfu/ml), except for B. Longum. Legume milk yogurt formulation had higher nutritional composition than legume flour yogurt formulation, where the highest protein content was recorded by SBMY. Significant pH reduction during storage had led to an increase in lactic acid percentage in legume yogurts. Meanwhile, high buffering capacity in legume milk yogurt formulation managed to retain higher lactic acid percentage compared to legume flour yogurt formulation, indicating better viability of probiotic bacteria. All legume yogurts possessed shear thinning behaviour (n<1) with varied color (L*, a* and b*) compositions. These properties were largely influenced by their species hereditary chemical composition and colored pigments, respectively. Besides, smoother textured yogurts with no grittiness were obtained from legume milk yogurt formulation, especially with PPMY. Meanwhile, further improvements are necessary to enhance the WHC and consumer's acceptability on the legume yogurts.