SciresolSciresolhttps://www.jcbsonline.ac.in/Journal of Clinical and Biomedical Sciences2319-245310.58739/jcbs/v13i4.23.20Original ArticlePhysico, Chemical and Functional Properties of Different Millets and their Suitability for Preparation of Enhanced Nutritious LadduPhysico, chemical and functional properties of milletsCyerin PriyaSamarpitha1ReddyMadhavidrmmadhavireddy@gmail.com2ChandanaK C3Ⅰ Year MSc, Department of Clinical Nutrition and Dietetics , SDUAHERKolar, KarnatakaProfessor, Department of Clinical Nutrition and Dietetics , SDUAHERKolar, KarnatakaⅠ Year MSc Department of clinical nutrition and dietetics , SDUAHERKolar, Karnataka1341152023Abstract
Millets are a nutrient-rich staple meal for the world's poor, and increasing the nutrient bioavailability is one of the key strategies for promoting their use. To enhance the edible, nutritive, and sensory qualities of millets, they are often prepared using conventional processing methods. Thus an attempt was made with an objective to assess the physical and functional properties of sprouted and unsprouted millets and to observe the acceptability of the laddu prepared from sprouted and unsprouted millets. Physical and functional properties for both sprouted and unsprouted grain and flour were analyzed using standard techniques. These properties were studied in 4 different millets i.e. kodo millet, finger millet, little millet, and sorghum.Physico-chemical properties have shown that sprouted millets have some of the good cooking properties and sensory evaluation has also show to be more acceptable.
KeywordsMilletsSoakingSproutingUnsproutedLadduPhysical And Functional PropertiesNutrient CompositionNoneIntroduction
One of the most often consumed cereal grain is millet. More than one-third of people on the planet consume millets. It ranks as the sixth most significant cereal crop when it comes to worldwide agricultural production 1. These seven varieties are: kodo millet (Paspalum setaceum), little millet (Panicum sumatrense), finger millet (Eleusine coracana), proso millet (Penicum miliaceum), barnyard millet (Echinochloa utilis), and pearl millet (Pennisetum glaucum) 2, 3. Millets have been known as "future cereals" due to their long-term viability and little environmental impact 4. All millets have nutritious values that are three to five times higher than those of regularly consumed grains like rice and wheat. Millets have several nutritional and health benefits, and they can help treat diseases including diabetes mellitus, hyperlipidemia, and other illnesses 1. India's top millet-producing state is Karnataka 5. Millets are exceptional for their nutritional and medicinal benefits, but they are underutilised due to its poor cooking quality, insufficient knowledge in processing, and low nutrient bioavailability 6. It has been found that processing methods like soaking, sprouting, and cooking increase plant grains nutritional value. In vitro digestibility and mineral availability are improved by sprouting method and it also helps in lowering the anti-nutritional components 7. Studies in the past have emphasised the significance of sprouting because it increases the nutrients bioavailability in a variety of dietary grains, which has a significant impact on nutritional quality 7, 8, 9.
There is a little information on how the raw and sprouting of millets differs with respect to nutritional and physical-functional properties. Thus this study was aimed at minimizing this gap of knowledge by studying these properties on raw and sprouted millets and seeing the difference and developing a healthy traditional product laddu.
Materials and methods
Source of Data: This was a study conducted in the Department of Clinical nutrition and dietetics in Sri Devaraj Urs Medical College from November 2021 and March 2022. Approval from institutional ethics committee was taken.
StudyPeriod:November 2021 and March 2022.
Procurement and the processing of millets
The study is carried out by using 4 millet grains such as kodo millet, little millet, finger millet and sorghum. The millets were collected from the local market of Kolar. After procurement, grains were sieved to remove the small sand particles, dust, broken seeds and other extraneous materials. The grains were dived into 2 sections where 1st portion was allowed for sprouting and the 2nd portion was unsprouted. The millets that was separated to sprout was washed under running tap water and were soaked for 24 hours then it was tied in a moist muslin cloth to sprout at room temperature for 24, 48 and 72 hours. After sprouting, the grains were allowed for sun drying. Both the sprouted and unsprouted samples were divided into 2 sections where 1st section was mechanically ground into powder and the other section was not ground these were packed separately in airtight plastic bags and was stored for the further analysis.
Determination of physico-functional properties
The study was carried out in 2 phases where in 1st phase unsprouted and sprouted millet grains were used and in 2nd phase unsprouted and sprouted millet flours were used to see the physical- functional properties.
Phase 1
Thousand grain weight: Three sets of 1000 grains were randomly selected and the mean weight was expressed in g/1000 grains.
Thousand grain volume (ml): Water displacement method was used measure the volume of millet grains. Thousand grains were randomly selected and put in measuring cylinder with known volume of water. The volume was recorded in ml. then the volume of millet was calculated by subtracting the initial volume from final volume.
Bulk density: Weight by volume of was used to calculate the bulk density.
Phase 2
Particle size: Weighed hundred gram of flour was passed from bigger to smaller mesh size. The sample left on the mesh was weighed and recorded and the percentage was calculated.
Tapped bulk density (g/ml): Tapped bulk density was measured by taking a standard graduated cylinder of 100ml capacity. Initially, the empty measuring cylinder was measured and noted, to it 20g of flour was added and tapped for 20-25 times to tightly pack the flour materials and the volume of the weighed sample was recorded. The tapped bulk density (TBD) of flour was determined by following formula 10.
Tapped bulk density (g/ml)= weight of the sample at recorded volume (g) volume of sample (ml)
Loose bulk density: The flour sample was poured into a 10ml of measuring cylinder. When the sample volume reached 1 ml the sample weight was measured. The weight and the volume was divided and calculated to obtain loose density 10.
Loose bulk density (g/ml)= weight of the flour at 1ml volume of the sample (1ml)
Waterabsorptioncapacity:QuinandPaton (1983) method was used to measure water absorption capacity. Centrifuge tube was weighed (W1) to it five grams of flour was added and stirred for 5 min using glass rod. For 30 mins the contents were allowed to stand and then it was centrifuged for 25 min at 11000 rpm. The free liquid was poured off. Tissue paper was used to wipe the inner side of tube. The centrifuge tube was weighed again (W2). The water absorption capacity was calculated using the formula;
Water absorption capacity, WAC (%)= W 2- W 1×100/5
Oil absorption capacity: Oil absorption capacity was assessed by using 11. Centrifuge tube was weighed (W1) to it 1 gram of flour and 10 ml of refined oil was added and stirred for 1 min for the complete dispersion of sample. The sample was centrifuged for 25 min at 3000 rpm. The oil that was separated was removed and the remaining oil was drained off by inverting the tube on an absorbent paper prior to reweighing (W2). The absorption capacity was calculated using formula;
Oil absorption capacity, OAC (%)=w2-w11×100
Swelling power: Schoch (1964) method was used to measure swelling power and solubility. Five hundred milligram (W1) of the sample was poured in a centrifuge tube and weighed (W2) to it twenty ml of distilled water was added (VE). Water bath was used to heat this at a temperature of 900C for 30 mins, with occasional stirring, the tubes were cooled and centrifuged at 5000 rpm for 10 min. The supernatant was poured into a pre-weighed (W4) petriplate and dried at 1050C and weighed (W5). The inner side of the centrifuge tube was wiped, dried and weighed (W3). Per cent swelling power were calculated using the following formulae
Swelling power (g/g)=W3-W2W1×1
Percent Dispersibility: 100 ml of stoppered measuring cylinder was taken to it 10 grams of sample and 100ml of distilled water was added and stirred vigorously and was allowed to settle for three hours. The settled particles volume was recorded and subtracted from 100. The difference was recorded as per cent dispersibility 12.
Wettability: A beaker was taken to it 2 grams of sample and 80 ml water was added. The behavior of the sample was observed on the water surface immediately after adding the sample. After 30 min of observation, magnetic stirrer was used to stir the material. The stirring was fast enough to form a vertex that reached the bottom of the beaker and this continued for one min, after which the grades were described and recorded as excellent, good, fair and poor according to the time and behavior of the dispersion.
Flowability [Carr Index (CI)]: The flowability of flour was expressed as Carr Index (CI) in terms of tapped density (pT) and bulk density (pB) as described by 13.
CI=pT( Tapped density -pB( bulk density )pT( Tapped density )×100
Classification of flour flowability based on Carr Index (CI)
CI%
Flowability
< 15
Very good
15-20
Good
20-35
Fair
35-45
Bad
>45
Very bad
Cohesiveness (Hausner Ratio): Cohesiveness of the flour was evaluated in terms of Hausner ratio (HR), calculated from bulk density (pB) and tapped density (pT) as suggested by 13.
HR = pT/Pb
Classification of flour cohesiveness based on Hauser Ratio (HR)
Hauserratio
Cohesiveness
<1.2
Low
1.2-1.4
Intermediate
>1.4
High
Gelation temperature: Six per cent aqueous solution of flour/starch was prepared into a beaker. Boiling water bath was used to heat the solution and the solution was stirred continuously until the solution gets gelatinized. At the point of gelatinization, the temperature was noted with thermometer. Time required for the initiation of gelatinization was recorded.
Percentsag:Six per cent starch/flour solution was prepared and cooked. The gelatinized solution was poured into a cup and it was placed in refrigerator for one hour. After cooling the height of the gel was measured in the cup with toothpick and scale. Cooled gel was inverted on flat surface; again height was measured with toothpick and scale. The per cent sag was calculated using the formula
Percent sag = Initial height in cup-final height on flat surface initial height in cup ×100
Paste clarity: A 0.5 per cent (dry basis, w/v) aqueous suspension of starch/flour was prepared and heated in boiling water bath for 30 min with constant stirring. The mixture was cooled to room temperature. The transmittance of the paste was measured at 650nm against a water blank using spectrophotometer 14.
Viscosity:Viscosity for five per cent aqueous solution of sample was determined using Brookfield viscometer (Ⅶ), spindle No.2 and speed 60 RPM at 310C and viscosity was expressed as centipoises (cP). Viscosity was also measured for hot slurries after heating them at 700C for 15 min.
Product preparationMethod of preparation
Add 100g of millet flour and ghee in a pan and combine it well. Roast it till nice aroma is obtained
Add 92g of Jaggery, 5g of powdered cardamom and cashews almonds to the roasted millet flour and mix well
Add 4g of milk powder and combine it take 15g of mixture and give it a shape
Radar chart representing the results of sensory evaluation of sprouted and unsprouted millet ladoo
The results of the general characteristics of the millets are presented below in the Table 1, Table 2, Table 3. Sprouted millets are found have higher TKW, TKV, bulk density except in sorghum, PS except in finger millet, TBD except in little millet, LBD except in finger millet. Except in sprouted kodo millet, all the other sprouted millets are found to have lower WAC, OAC in sprouted millets is found to be lower in all four millets, SWP is found to be higher in all four types of sprouted millets, PD is lower in sprouted millets, wetability is found to be fair in sprouted and unsprouted kodo millet and sprouted little millet, whereas, unsprouted little millet, sprouted and unsprouted finger millet and sorghum is found to have good wettability, cohesiveness is found to be low in all the millets, gelation temperature is found be higher in sprouted millets except in sprouted little millet, percent sag is found to be lower in sprouted kodo millet and higher in sprouted finger millet and sorghum, paste clarity is found to be higher in sprouted millets and viscosity is found to be higher in sprouted millets except in sprouted sorghum.
The sensory quality parameters namely, appearance, texture, flavor, taste, aroma, and overall acceptability of the both ladoos values are listed in the Table 4. It is observed that the panelist could not find any significant difference (p < 0.05) between USML and SML in appearance, flavor, taste, aroma, and overall acceptability. Although, in this study, the SML variation had higher acceptability in terms of organoleptic quality when compared to the USML.
Discussion
Understanding the physicochemical characteristics of millet cultivars is crucial from a processing and nutritional security perspective. One of the key factors in food processing, packing, storage, and transportation operations, as well as in a number of post-harvest processes involving cereal grains, is physicochemical qualities 15. The various physical properties is observed and shown in Table 1, Table 2, Table 3.
The WAC measures how much water a starch can hold compared to its weight. The degree of starch gelatinization is indicated by higher WAC. Because millets have a higher WAC, they may be more useful for generating flours that can be used to make a variety of foods that need a good viscosity 16. No significant differences are found between unsprouted and sprouted millets. Higher WAC was found in sprouted kodo millet and unsprouted finger millet compared to other millets. The presence of fewer hydrophobic amino acids can be linked to decreased OAC 17. Significant differences are observed in sprouted and unsprouted millets. Sprouting led to the significant reduction in the OAC. Significant differences in swelling power is observed in little millet and finger millet. Several studies have confirmed the inverse relationship between swelling power and moisture content, i.e. that as flour absorbs more water, its swelling power decreases 17. Compressibility index, commonly known as Carr's index, is a measurement of the flowability of flour; specifically, flour with CI less than 15 has acceptable flowability, whereas flour with CI exceeding 35 demonstrates bad Flowability 17. Flowability is found to be very bad in unsprouted kodo millet, unsprouted sorghum and in both sprouted and unsprouted little millet. Fair flowability in unsprouted finger millet. Gelatinization is an irreversible phase transition phenomenon that happens when starch is subjected to high temperatures and water. Gelatinization temperatures are important for choosing particular starch qualities in accordance with needs in a variety of food applications 18. Significant differences is observed in little millet, finger millet and sorghum. No significant differences is observed in paste clarity except in little millet. Paste clarity of starches is an important property of starch pastes because it affects the desired consistency of food products such as jellies and fruit pastes 18. One of the variables that may affect the overall characteristics of reconstitution and/or mixing is wettability. Due to their low specific surface area, texture/microstructure, and chemical makeup, many typical dry sample powders take a long time to saturate, indicating poor wettability. The capacity of a powder to absorb water is measured by its wettability. Therefore, the wettability decreases as the wetting time increases 19. Both sprouted and unsprouted kodo millet and sprouted little millet is found to have fair wetability whereas the other millets is found to have good wetability.
In the sensory evaluation it is found that ladoo prepared from sprouted millets to have more overall acceptability when compared to the ladoo prepared from unsprouted millets.
Conclusion
The present study concludes that the sprouted millets have a some of the good cooking properties than unsprouted millets and sensory evaluation also showed that ladoo prepared from sprouted millets were more acceptable than the ladoo prepared from unsprouted millets.
ReferencesAmbatiKK V SMillets-Review On Nutritional Profiles And Health BenefitsInt J Recent Sci Res201910I3394333951https://www.recentscientific.com/sites/default/files/14234-A-2019.pdf?fbclid=IwAR2AMaT7nEr1ulo5rvKKptHDm77O84ZUwOJJom-Lx4YV1i_Y2RGKt71p4lUSalehAhmed S MZhangQingChenJingShenQunMillet Grains: Nutritional Quality, Processing, and Potential Health BenefitsComprehensive Reviews in Food Science and Food Safety20131232812951541-4337Wiley https://doi.org/10.1111/1541-4337.12012ShahidiFereidoonChandrasekaraAnomaMillet grain phenolics and their role in disease risk reduction and health promotion: A reviewJournal of Functional Foods2013525705811756-4646Elsevier BVhttps://doi.org/10.1016/j.jff.2013.02.004SharmaBharatiGujralHardeep SinghModulation in quality attributes of dough and starch digestibility of unleavened flat bread on replacing wheat flour with different minor millet floursInternational Journal of Biological Macromolecules20191411171240141-8130Elsevier BVhttps://doi.org/10.1016/j.ijbiomac.2019.08.252UpadhyayaH DGowdaCllReddyV GMorphological diversity in finger millet germplasm introduced from Southern and Eastern Africa SAT eJournal2007313https://oar.icrisat.org/2656/1/Morphological_diversity_in_finger.pdfYangXiaoyanWanZhiweiPerryLindaLuHouyuanWangQiangZhaoChaohongLiJunXieFeiYuJinchengCuiTianxingWangTaoLiMingqiGeQuanshengEarly millet use in northern ChinaProceedings of the National Academy of Sciences201210910372637300027-8424Proceedings of the National Academy of Scienceshttps://doi.org/10.1073/pnas.1115430109DeviChingakham BasantiKushwahaArchanaKumarAnilSprouting characteristics and associated changes in nutritional composition of cowpea (Vigna unguiculata)Journal of Food Science and Technology20155210682168270022-1155Springer Science and Business Media LLChttps://doi.org/10.1007/s13197-015-1832-1PushparajFlorence SumaUroojAsnaInfluence of Processing on Dietary Fiber, Tannin and <i>in Vitro</i> Protein Digestibility of Pearl MilletFood and Nutrition Sciences201102088959002157-944XScientific Research Publishing, Inc.https://file.scirp.org/pdf/FNS20110800012_97367493.pdfMajidIshratNandaVikasEffect of sprouting on the physical properties, morphology and flowability of onion powderJournal of Food Measurement and Characterization2017114203320422193-4126Springer Science and Business Media LLChttps:/doi.org/10.1007/s11694-017-9586-2GoulaAthanasia MKarapantsiosThodoris DAchiliasDimitris SAdamopoulosKonstantinos GWater sorption isotherms and glass transition temperature of spray dried tomato pulpJournal of Food Engineering200885173830260-8774Elsevier BVhttps://doi.org/10.1016/j.jfoodeng.2007.07.015SosulskiF WElkowiczLReichertR DOligosaccharides in Eleven Legumes and Their Air‐Classified Protein and Starch FractionsJournal of Food Science19824724985020022-1147Wiley https://doi.org/10.1111/j.1365-2621.1982.tb10111.xKulkarniKaruna DKulkarniD NIngleU MSorghum Malt-Based Weaning Food Formulations: Preparation, Functional Properties, and Nutritive ValueFood and Nutrition Bulletin1991134170379-5721SAGE Publicationshttps://doi.org/10.1177/156482659101300401JinapongNakarinSuphantharikaManopJamnongPimonProduction of instant soymilk powders by ultrafiltration, spray drying and fluidized bed agglomerationJournal of Food Engineering20088421942050260-8774Elsevier BVhttps://doi.org/10.1016/j.jfoodeng.2007.04.032WuYueLinQinluCuiTingXiaoHuaxiStructural and Physical Properties of Starches Isolated from Six Varieties of Millet Grown in ChinaInternational Journal of Food Properties20141710234423601094-2912Informa UK Limitedhttps://doi.org/10.1080/10942912.2013.803119PawasePPhuleMVidyapeethKChavanU DPhuleMVidyapeethKEvaluation of functional properties of different pearl millet cultivarsThe pharma Innovation International Journal2021https://www.researchgate.net/publication/352875335_Evaluation_of_functional_properties_of_different_pearl_millet_cultivarsPandaDebabrataSailajaN HemaPadhanBandanaLenkaKartikSprouting-Associated Changes in Nutritional and Physico-Functional Properties of Indigenous Millets from Koraput, IndiaProceedings of the National Academy of Sciences, India Section B: Biological Sciences202090179860369-8211Springer Science and Business Media LLChttps://doi.org/10.1007/s40011-019-01085-xRaoMadaraboina VenkateswaraKGAkhilCKSunilEffect of microwave treatment on physical and functional properties of foxtail millet flourInternational Journal of Chemical Studies202191276227672349-8528AkiNik Publicationshttps://doi.org/10.22271/chemi.2021.v9.i1am.11641PuniaSnehKumarManojSirohaAnil KumarKennedyJohn FDhullSanju BalaWhitesideWilliam ScottPearl millet grain as an emerging source of starch: A review on its structure, physicochemical properties, functionalization, and industrial applicationsCarbohydrate Polymers20212601177760144-8617Elsevier BVhttps://doi.org/10.1016/j.carbpol.2021.117776IsmaelSamah ASoltanSaharAhmedHodaMohamedReda ElEl-WakeelMahmoudChemical and functional properties of free-gluten biscuit making from corn, quinoa and millet floursAfrican Journal of Biological Sciences2019151235252Egypts Presidential Specialized Council for Education and Scientific Researchhttps://journals.ekb.eg/article_192981.html