Morphology, physico-chemical and functional characteristics of starches from different banana cultivars

Influence of chemical modifications on dynamic rheological behaviour, thermal techno-functionalities, morpho-structural characteristics and prebiotic activity of banana starches

Banana starch is explored for its use in food and pharmaceutical applications. In this study, in order to improve the techno-functional properties of native banana starch (NS), different chemical modifications namely acid thinning (AT), oxidation (OX), sodium-trimetaphosphate method (STMP), cross linking phosphorylation (CLP), hydroxypropylation (HYP) were employed. Among the modified starches, amylose content was higher in CLP starch and the least was observed in AT. Resistant starch (RS) of HYP (65.38 %) and CLP starches (62.76 %) were significantly higher than other modified starches. Lesser amylose, higher water solubility and lower swelling of AT starch resulted in inferior paste clarity and inability to make a firm gel. Non-Newtonian behaviour of starch gels were observed from static viscosity observations. The dynamic rheological behaviour of the starch gels affirmed the higher gel strength of STMP (0.46) and CLP (0.56) starches. Imperfection and exo-corrosion in starch morphology was observed through SEM and influence of chemicals on the starch structure was elucidated through FTIR and XRD analyses. Except AT starch, modified starches with higher RS resulted in lowering glycemic index (57-69 %). STMP starches recorded highest prebiotic activity score of 0.88. Chemical modifications enable to enhance the functionalities of banana starch and offers potential industrial uses.

Influence of γ-irradiation on physicochemical, functional, proximate, and antioxidant characteristics of pigmented rice flours

In recent years, food irradiation using γ-rays is one of the most valuable practices for insect disinfestation in rice grains for extended shelf life. In this study, flours from four pigmented rice cultivars were exposed to γ-irradiation using 60Co at different doses (0, 5, 10, and 15 kGy). The impact of γ-irradiation on the physico-chemical, functional, and morphological characteristics of pigmented rice flours were analyzed. Results revealed that reduction in amylose content, pH, bulk density, tapped density, and syneresis, while solubility, water absorption capacity, and swelling power values increased significantly (p < 0.05). Pasting characteristics of pigmented rice flours also reduced after exposure to γ-irradiation. Morphological features of pigmented rice flour granules revealed no evidence of physical destruction after irradiation except for black kavuni flour. The structural analysis by FTIR confirms no effect of γ-irradiation on pigmented rice flours. Overall, the study revealed that irradiated pigmented rice flours with enhanced functional properties of less than 10 kGy can be effectively used in the development of value-added rice-based food products considering all the beneficial and safety aspects.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-023-05709-z.

Study on structural characteristics and physicochemical properties of starches extracted from three varieties of kudzu root (Pueraria lobata starch)

Kudzu root (Pueraria lobata) is well known for its traditional use as a medicinal food homologous plant in China. Three varieties of kudzu roots, such as Gange-1, Gange-2, and Gange-6, are commonly used. Nowadays, kudzu starch (KS) is commercially available as satiating foods or product ingredients. Differentiation and selection of the variety are important components of quality control for KS-based products. Thus, the present work was aimed at comparing the physicochemical properties, such as thermodynamic properties, pasting properties, solubility, swelling, as well as the structural characteristics of the starches extracted from the three varieties of kudzu roots. The results show that KS-6 has a higher content of functional ingredients thus can be used as an ideal functional starch. However, KS-6 has a higher amylopectin:amylose ratio of 4.65, resulting in a better solubility, higher transition temperature, and higher gelatinization enthalpy. KS-2 showed lower transition temperature and gelatinization enthalpy, as well as higher peak viscosity, through viscosity, and final viscosity. KS-1 could result in a soft texture after pasting. The appropriate variety of KS should be differentiated and selected according to application scenarios. This study provided valuable insights into the potential use of different KS in the food and nonfood industries. PRACTICAL APPLICATION: 1. KS-1 was found to be suitable for use as a food supplement. 2. KS-6 has the highest nutritional value. 3. They can be used as a substitute for other similar starches.

The Properties, Modification, and Application of Banana Starch

Banana is a tropical fruit crop that is consumed at large, not only because of the quantity produced but also because it serves the calorific needs of millions of people. Banana is a potential source of high starch content (more than 60%). The application of starch for various purposes is dependent upon its structural, physicochemical, and functional properties. A native starch does not possess all required properties for specific use in the food product. To improve its application, starch can be modified physically, chemically, and enzymatically. Each of these modification methods provides different characteristics to the modified starch. This review aims to examine the chemical composition, granule morphology, crystallinity, pasting, thermal properties, and digestibility of banana starch, and discusses the various modifications and potential applications of banana starch in the food industry.

Indirect Quantitative Analysis of Biochemical Parameters in Banana Using Spectral Reflectance Indices Combined with Machine Learning Modeling

The primary issues in collecting biochemical information in a large area using chemical laboratory procedures are low throughput, hard work, time-consuming, and requiring several samples. Thus, real-time and precise estimation of biochemical variables of various fruits using a proximal remote sensing based on spectral reflectance is critical for harvest time, artificial ripening, and food processing, which might be beneficial economically and ecologically. The main goal of this study was to assess the biochemical parameters of banana fruits such as chlorophyll a (Chl a), chlorophyll b (Chl b), respiration rate, total soluble solids (TSS), and firmness using published and newly developed spectral reflectance indices (SRIs), integrated with machine learning modeling (Artificial Neural Networks; ANN and support vector machine regression; SVMR) at different ripening degrees. The results demonstrated that there were evident and significant differences in values of SRIs at different ripening degrees, which may be attributed to the large variations in values of biochemical parameters. The newly developed two-band SRIs are more effective at measuring different biochemical parameters. The SRIs that were extracted from the visible (VIS), near-infrared (NIR), and their combination showed better R2 with biochemical parameters. SRIs combined with ANN and SVMR would be an effective method for estimating five biochemical parameters in the calibration (Cal.) and validation (Val.) datasets with acceptable accuracy. The ANN-TSS-SRI-13 model was built to determine TSS with greater performance expectations (R2 = 1.00 and 0.97 for Cal. and Val., respectively). Furthermore, the model ANN-Firmness-SRI-15 was developed for determining firmness, and it performed better (R2 = 1.00 and 0.98 for Cal. and Val., respectively). In conclusion, this study revealed that SRIs and a combination approach of ANN and SVMR models would be a useful and excellent tool for estimating the biochemical characteristics of banana fruits.

Physicochemical and Morphological Characteristics of Starch and Flour Obtained from Green Banana cv. Raja (Musa paradisiaca cv. Raja) in West Sumatra, Indonesia

&lt;b&gt;Background and Objective:&lt;/b&gt; Banana cv. &lt;i&gt;Raja&lt;/i&gt; is widely cultivated in West Sumatra, Indonesia. The physicochemical properties of starch and flour were investigated to determine their functional food prospects in industrial food. &lt;b&gt;Materials and Methods:&lt;/b&gt; Starch and flour of banana cv. &lt;i&gt;Raja&lt;/i&gt; was characterized using proximate analysis, Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), Fourier-Transform Infrared (FT-IR), X-Ray Fluorescence (XRF) and Rapid Visco-Analyzer (RVA). &lt;b&gt;Results:&lt;/b&gt; Banana cv. &lt;i&gt;Raja&lt;/i&gt; starch contains 40.73% starch, 17.49% amylose, 55.5% water, 0.66% ash, 0.83% protein and 0.18% fat. The size of the granules is ranging from 20-30 μm in irregular and ellipsoidal-truncated shapes. The structure of crystallinity belongs to the type B while the gelatinization temperature is 74.9°C. Furthermore, the starch composed of 41.06% potassium, 12.85% phosphorus, 12.74% iron, 9.4% calcium and 7.5% magnesium. &lt;b&gt;Conclusion:&lt;/b&gt; The morphological and physicochemical starch characteristics of Banana cv. &lt;i&gt;Raja&lt;/i&gt; and has similar characteristics with its flour. Meanwhile the swelling power and the solubility value of the flour were higher than the starch. The gelatinization temperatures of starch and flour were 74.9 and 73.4°C, respectively.

Exploring differences in the physicochemical, functional, structural, and pasting properties of banana starches from dessert, cooking, and plantain cultivars (Musa spp.)

Banana starch, with its nutritional and functional properties, opens up new opportunities for the food industry, which is seeking new starch sources to fulfil rising demand. Herein, physico-chemical, and functional properties of banana starches isolated from dessert, plantain, and cooking cultivars were investigated. Starch yield was higher in Popoulu (30.58%) and Monthan (27.82%). Starch granules registered irregular forms with granule sizes ranging from 8.9 to 55.09 μm. Among the cultivars, the amylose content was ranged between 25.05 and 31.86%. Total starch (95.86 and 95.60%,) and resistant starch (65.56 and 59.20%) were higher in Saba and Monthan respectively. Flour colour index (86.2-90.6) was higher in banana starches. Differential scanning calorimetry and rapid viscosity studies confirmed that starches from Saba (87.67 and 85.71 °C) Monthan (85.36 and 81.65 °C) have a higher gelatinization property. Banana starches were B and C-type with varying crystallinity levels (21.19-52.01%). The in-vitro starch digestibility revealed that Saba starch has a lower hydrolysis rate with lesser glycemic index. PCA showed the greater impact of amylose and resistant starch content on the grouping of varieties. These findings would be useful for food and non-food industries in terms of using banana starch in various food compositions and other industrial applications.

Non-invasive, real time in-situ techniques to determine the ripening stage of banana

Bananas were examined starting from ripening stage R2 (green) to stage R7 (overripe), to identify suitable non-invasive, real time in-situ technologies to separate the ripening stages: (1) Chlorophyll degradation, measured by the DA meter, decreased from ca. 2.1 (R2) to 0.2 IAD units (R7), i.e. tenfold decline. (2) Colour CIE-Lab a values dramatically increased as indication of chlorophyll breakdown and enable differentiation between all ripening stages R2 to R7. Colour angles declined from 98.7° hue (R2), 97.3° hue (R3), 92.7° hue (R4), 89.4° hue (R5); 87.5° hue (R6) until 82.0° hue (R7). (3) Spectroscopy showed two light reflectance troughs at 494 nm and 679 nm. A novel banana ripening index (BRI) was developed and is proposed to identify and distinguish the ripening stages of banana with values starting at 4 at R1 and peaking at 8.1 at ripening stage R7. (4) Peel gloss increased from stage R2 (150 a.u.) to stage R7 (220 a.u.) in the order of ca. 50% followed by a subsequent decrease thereafter. (5) Peel softening declined as fruit firmness dropped from 82 Shore at stage R2 to 42 Shore at stage R7 (overripe), measured also at the centre of the banana fruit. (6) After a constant 90.5% water content per fresh mass (FM) in the banana peel until stage R5, the subsequent drop to 82.9% FM at R7 and 7.6% water translocation viz displacement from the peel to pulp explained this softening. All the above results identified the fruit centre (rather than the tip) as a suitable candidate due to the most advanced ripening and least curved surface region of the fruit with easy access, when a carton is opened and the hands become accessible. This novel approach based on a comparison has shown the DA-meter, colorimeter and spectrometer as suitable candidates for the identification of each ripening stage. The combination of these three devices may be suitable for monitoring of banana ripening rooms in terms of temperature and humidity in addition to the present, colour-based ripening scale.

Functional Properties of Banana Starch (Musa spp.) and Its Utilization in Cosmetics

Unripe banana fruit of Musa acuminata (Musa AAA; Hom Khieo) and Musa sapientum L. (Musa ABB; Namwa) growing in Chiang Rai (Thailand) were used for extraction. The yield of the starches was 16.88% for Hom Khieo (HK) and 22.73% for Namwa (NW) based on unripe peeled banana fruit. The amylose contents of HK and NW were 24.99% and 26.23%, respectively. The morphology of starch granules was oval shape with elongated forms for large granules and round shape for small granules. The HK and NW showed B-type crystalline structure and the crystallinities were 23.54% and 26.83%, respectively. The peak temperature of gelatinization was around 77 °C and the enthalpy change (ΔH) was 3.05 and 7.76 J/g, respectively. The HK and NW banana starches showed 1.27 ± 0.12 g/g and 1.53 ± 0.12 g/g water absorption capacity, and 1.22 ± 0.11 g/g and 1.16 ± 0.12 g/g oil absorption capacity, respectively. The swelling power of the banana starches was 17.23 ± 0.94 g/g and 15.90 ± 0.15 g/g, respectively, and the percentage of solubility in water showed 26.43 ± 2.50 g/g and 20.54 ± 0.94 g/g, respectively. The banana starches showed very poor flow character. The HK and NW starches have the potential to be used in powder base preparations with no effect on the sensory texture of the product at 15% w/w maximum.

Influence of freeze-drying and fresh cooking on starch morphology and physicochemical and thermal properties of various tropical tubers

Flours and starches extracted from the tropical tubers underwent freeze-drying and cooking in comparison with fresh cooking. Freeze-dried and cooked starch (FDS) granules were found to have different shapes and collapsed arrangement whereas freshly cooked starch (FCS) granules had the least varied structures. The freeze-dried flours had larger structures compared to freshly cooked flours. The physicochemical parameters were high in Dioscorea esculenta (DE)-FDS, followed by Amorphophallus paeoniifolius (AP)-FDS and other samples whereas D. alata (DA)-FCS had the lowest, whereas flours followed similar trend. FDS (42.1%) had the highest solubility index and swelling power whereas FCS (11.1%) showed the lowest. The syneresis and light transmittance levels were higher in FDS and FDF. The freeze dried flour and starch showed higher onset (T₀), peak (T_P), and conclusion (T_C) temperature than fresh cooked samples. The variations in IR spectra, thermal properties, and crystalline index were termed as differential function of physicochemical characteristics, structural changes that resulted from freeze drying, and cooking treatment employed.

Densely packed-matrices of heat moisture treated-starch determine the digestion rate constant as revealed by logarithm of slope plots

Factors affecting the extent and rate constant of starch digestion have been determined by applying logarithm of slope (LOS) plot approach to banana starch modified by heat moisture treatment (HMT) at different temperatures (100, 110 and 120 °C) and time (4 and 8 h). LOS plot result showed that native and HMT-starches exhibited two separate digestion rate constants (k ₁ in rapid and k ₂ in slower phase). The digestibility increased with the increase in temperature and time of HMT in which the amount of digestible starch at slower phase (C _2∞ ) predominantly contributed to the increase in total digestible starch (total C _∞ ). Small change of the digestible starch in rapid phase (C _1∞ ) might be attributed to the comparatively intact granule surfaces and the relatively small change in ratio of ordered to disordered α-glucan chains at the granule surface as observed by FTIR-ATR. Meanwhile the increase in C _2∞ might be linked to the decrease in crystallinity as observed by XRD. Compared to the native starch, denser packed-structure characterising an A-type crystalline structure in HMT-starches is a key factor determining the lower k ₂ in HMT-starches. The densely packed-matrices might slow down the amylase diffusion through the granule to reach digestible α-glucan chains.

Evaluation of the Content of Polyphenols, Antioxidant Activity and Physicochemical Properties of Tortillas Added with Bambara Groundnut Flour

The effect of substituting maize (masa) flour with Bambara groundnut flour in tortillas production was investigated. Thermal, antioxidant, physicochemical properties, degree of puffing and rollability of flour and tortillas were determined. Tortillas were produced from maize and Bambara Groundnut (BGN) flours at the ratio of 100:0, 95:5, 90:10, 85:15 and 80:20, respectively. Compositing maize with BGN flour showed an improvement on the proximate composition of maize flour and tortillas; however, carbohydrate content of tortillas significantly decreased with the addition of BGN in blends from 77.07 to 55.22. The temperatures of gelatinisation such as onset temperature (T_o) of flour blends increased from 57.50 to 71.95 °C, peak temperature (T_p) from 74.94 to 76.74 °C and the end temperature (T_e) from 81.72 to 91.58 °C. Composite flours and tortillas had higher values of polyphenolic compounds and antioxidant activities than the control sample. Textural properties of control tortillas were higher than that of composite tortillas. Increase in the levels of BGN flour improved the weight and thickness of tortillas. However, diameter and spread ratio decreased. Degree of puffing and rollability of tortillas increased with the incorporation levels of BGN flour.

Physicochemical and Functional Properties of Chemically Pretreated Ndou Sweet Potato Flour

Sweet potato (Ipomoea batatas Lam) is a nutritious crop abundant in calories and bioactive compounds such as beta-carotene, ascorbic acid, polyphenols, and dietary fibre. This study investigated the effect of pretreatments on the physicochemical and functional properties of Ndou sweet potato (NSP) flour. Flour samples were prepared by randomly assigning NSP slices to two treatments (citric acid and sodium metabisulphite) at 5, 10, and 15 g/L concentration for 10 min. Distilled water was used as control. The moisture content (7.70%) of NSP flour treated with citric acid was significantly (p < 0.05) higher than that of the flour treated with sodium metabisulphite (5.54%) as the concentration level increased. The treatments did not significantly (p < 0.05) affect the protein and fat contents of the NSP flour and protein increased from 2.54 to 2.82%, while fat decreased from 0.69 to 0.61%. Sodium metabisulphite treated samples had a higher L^∗ value, ash, and pH level than citric acid treated samples. However, pH was slightly decreased by both treatments from 6.05 to 5.09. Citric acid treated samples had higher a^∗ and b^∗ values than sodium metabisulphite treated samples. In terms of the functional properties of NSP flour, the treatments significantly (p < 0.05) affected the water absorption capacity, viscosity, swelling power, solubility index, and thermal properties although the bulk density and least gelation concentration were not significantly (p > 0.05) affected. Sodium metabisulphite was very effective in improving physicochemical and functional properties of NSP flour as compared to citric acid. The findings of this study show the possibilities of using NSP flour in food systems as gelling agent, fat replacer, and thickeners.

Non-invasive determination of surface features of banana during ripening

Ripening of dessert banana (Musa sap.) is associated with changes in colour (green to yellow starting from the cente), softening, and surface features. These have mostly been investigated using distinct technologies. Hence, here changes in surface features were examined with two novel, non-invasive techniques: a luster sensor and a 3D profilometer. The profiler measures the 3D surface characteristics of an area, rather than a single profile line, and corrects data for curvature of the fruit. The luster sensor detected an increase in glossiness from stage 3 (green) to stage F7a (ripe) of ca. 35%, followed by a decrease in glossiness from stage F7a to F7b (overripe). The profilometer provided visual and parametric roughness values (Ra) for ripening. Cavendish bananas showed an increase from 2.5 to 6.6 µm during ripening stage 3 (green) to stage 7b (overripe). Another roughness value, Rz, increased concomitantly from 13.1 µm at stage 3 (green) to 26.9 µm at stage F7b (overripe). The study showed that the centre of the fruit was the best region for surface imaging, because it was the most advanced ripening part of the banana fruit, easily curved, and the region of the fruit can be accessed when a carton was opened. This study shows that it is now possible to monitor the changes in surface glossiness and roughness during the ripening of Cavendish bananas using two novel non-invasive technologies. The compact luster sensor may become a component of a portable probe and manual control of packing units. Differences in the predicted green life can be used to prioritize containers for unloading in the discharge port or to implement quality-based warehouse management strategies. Containers that arrive at banana ripening rooms before their green life ends, can be re-routed, in addition to the present, colour-based ripening scale.

Functional and physicochemical characteristics of cookies prepared from Amorphophallus paeoniifolius flour

This study was undertaken to prepare novelly formulated cookies from elephant foot yam flour (EFYF) with refined wheat flour (RWF) and evaluate their proximate composition, quality characteristics, texture, pasting and organoleptic properties. The formulated cookies prepared from EFYF, substituting RWF up to 70% had sensory properties similar to that of refined flour cookies (control). EFYF and RWF blend revealed reduced water and oil absorption capacity with increased peak and final viscosities when compared with RWF. Reduced lightness, increased redness and hardness were observed for formulated cookies with increase in storage time. Irrespective of the decreasing trend in their texture, overall acceptance of the EFYF cookies by the consumers was increased. Sensory scores revealed the preference of consumers towards formulated cookies. Overall analysis disclosed that the cookies prepared from A. paeoniifolius flour proved acceptable not only in quality characteristics but also fulfil the demand of functional foods in preparation of cookies.

Variety Difference in Molecular Structure, Physico-chemical and Thermal Properties of Starches from Pigmented Rice

Starches isolated from three different pigmented rice varieties (Chak-hao Amubi, Chak-hao Poireiton, and Chak-hao Angangba) and investigated for their molecular structure and physico-chemical properties including amylose content, morphology, crystallinity, pasting viscosity, color, thermal property, swelling power and solubility. Significant differences were detected in physico-chemical and functional properties (p≤0.05) of rice starches. The amylose content results revealed that Chak-hao Angangba (1.93 %) and Chak-hao Poireiton (1.98 %) are waxy rice, and Chak-hao Amubi (3.16 %) is a very low-amylose rice. The morphology of rice starch granules shown polyhedral edges with an irregular shape; and the XRD patterns of rice starches exhibited A-type crystalline patterns with peaks at 2θ=15.1°, 17.1°, 18.2° and 23.0°. Waxy rice starches shown higher peak viscosity and enthalpy with lower gelatinization temperatures than very low amylose rice starches. The pasting viscosity, swelling power and solubility crystallinity of rice starches were varied significantly (p≤0.05). Finally, the present study provides knowledge for the utilization of starches isolated from three pigmented rice varieties grown in North-Eastern part of India that would be relevant for both domestic and industrial applications.