Preparation of lactic acid bacteria compound starter cultures based on pasting properties and its improvement of glutinous rice flour and dough

The effects of 5 lactic acid bacteria(LAB)fermentation on the pasting properties of glutinous rice flour were compared,and suitable fermentation strains were selected based on the changes of viscosity,setback value,and breakdown value to prepare LAB compound starter cultures.The results revealed that Latilactobacillus sakei HSD004 and Lacticaseibacillus rhamnosus HSD005 had apparent advantages in increasing the viscosity and reducing the setback and breakdown values of glutinous rice flour.In particular,the compound starter created using the two abovementioned LAB in the ratio of 3:1 had better performance than that using a single LAB in improving the pasting properties and increasing the water and oil absorption capacity of glutinous rice flour.Moreover,the gelatinization enthalpy of the fermented samples increased significantly.For frozen glutinous rice dough stored for 28 days,the viscoelasticity of frozen dough prepared by compound starter was better than that of control dough,and the freezable water content was lower than that of control dough.These results indicate that compound LAB fermentation is a promising technology in the glutinous rice-based food processing industry,which has significance for its application.

Effect of Gluten on Pasting Properties of Wheat Starch

The effect of gluten on pasting properties of wheat starch was studied to provide a scientific basis for the application of gluten in food production and quality improvement in wheat breeding. The pasting properties of blends were analyzed using PH 1391 wheat starch mixed with five different additions of three kinds of gluten （strong-, medium-, and weak-gluten） and the structures of network were observed with microscope. The significant downtrends of peak viscosity, trough viscosity, final viscosity, area of viscosity, setback, and peak time were observed with the increase in the addition of gluten. In general, the average value of them decreased respectively by 3.6, 4.8, 3.4, 3.8, 4.0, and 1.18% of those corresponding indexes of pure starch for every 2% increase in gluten. The decreasing rate of the indexes mentioned above exceeded more than 2% except peak time, but there were no significant influence of gluten addition on breakdown, pasting temperature and pasting time. The inter layer composed of gluten was not observed when the addition of gluten was 10%, as the compound formed of gluten inlaid in the paste of starch, but obvious inter layer was detected when the addition of gluten was 18%. There was significant or remarkable difference among the effects of three different kinds of gluten on the peak viscosity, trough viscosity, area of viscosity, setback, and peak time, but it had no significant difference among the effects of different glutens on pasting temperature and pasting time. The descending order of the effect of different glutens on peak viscosity, trough viscosity, and area of viscosity was strong-, medium-, and weak-gluten, but the order of them for setback was opposite. Both addition and types of gluten significantly affected peak viscosity, trough viscosity, area of viscosity, setback, and peak time, but there were no significant effects of it on peak time and peak temperature.

Effects of Papain Hydrolysis on the Pasting Properties of Wheat Flour

As one of the most effective enzymatic modification methods of protein, papain hydrolysis is applied widely in food production, accompanying starch pasting frequently in order to improve industrial quality. Effects of the papain hydrolysis on flour pasting properties were investigated in five papain/flour concentrations and five time-treatments. The structure of starch and protein networks in slurry was investigated under microscope before and after pasting. Results showed that papain hydrolysis influenced the pasting properties of wheat flour significantly through affecting structural characteristics, amylase activity and exotbermic transition, especially during the early stage of hydrolysis. Peak viscosity, trough, final, integral area, and setback significantly decreased along with the increasing concentration of papain. Both hydrolysis time and concentration of papain had obviously effect on the breakdown. Pasting temperature and pasting time increased significantly with the enhancement of papain concentration. Hydrolysis time exerted minor effect on the pasting temperature and pasting time. The average peak time was slightly prolonged by lower concentration of papain, otherwise slightly shortened by higher concentration.

Structural, Pasting, and Thermal Properties of Ultra-high Pressure-treated Lotus Seed Starch

Lotus seed starch （15%, w/w） was subjected to ultra-high pressure （UHP） at 500 MPa for 10～60 min. The effects of UHP on the structural, pasting, and thermal properties of starch were investigated using solid-state 13C CP/MAS NMR, differential scanning calorimetry （DSC）, HPSEC-MALLS-RI, and a rapid visco analyzer. The 13C CP/MAS NMR results revealed a reduction in the relative crystallinity and peak intensity of the crystalline state with increasing the UHP time. The molecular weight of native starch was 1.433 × 107 Da, which was higher than that of the UHP-treated starch. Viscograms of UHP-treated starch revealed an increase in paste viscosity, peak time, and pasting temperature and a reduction in breakdown and setback viscosity compared to the native starch. Furthermore, the DSC results showed a reduction in gelatinization temperature and gelatinization enthalpy with increasing the UHP time.

Pasting properties by near-infrared re flectance analysis of whole grain paddy rice samples

A rapid predictive method based on near-infrared re flectance spectroscopy(NIRS)of paddy rice was developed to measure the pasting properties of rice.The paddy rice samples were scanned by a near-infrared re flectance spectrometer in the wavelength region of 1400–2400 nm and preprocessed by mathematical pretreatments prior to pasting properties analysis using a rapid visco-analyzer(RVA).The results indicated that the developed models of setback(SB),peak viscosity(PV),breakdown(BD)and consistency(CS)provided good prediction results with relatively high correlation coe±cients(0.81–0.96).In addition,the validity of the calibration models was statistically tested.Standard error of prediction(SEPT) and bias were small enough without any significance at 95% confidence interval.Nonetheless,this study proved that the use of NIRS for predicting pasting properties was feasible in paddy rice and could be applied in commercial trade and research.

Influence of Gum Arabic from <i>Acacia Senegal</i>var. <i>kerensis</i>on the Modifications of Pasting and Textural Properties of Cassava and Corn Starches

The use of hydrocolloids to modify the properties of native starches has been on the rise in the recent times due to the market demand for natural, safe and economical food ingredients. The objective of this study was to investigate the effect of gum Arabic from Acacia senegal var. kerensis to modify pasting and textural properties of corn and cassava starches, as an alternative to chemical and enzymatic modification. Blends were prepared by substituting the starches with gum at different levels (0%, 0.5%, 2.0%, 4.0%, 6.0% and 8.0%), whereas native corn and cassava starches were used as control. The pasting properties of the starch-gum mixed systems were determined using the Brabender viscograph while the textural properties (firmness, consistency, cohesiveness and work of cohesion) were determined using Texture Analyzer. Results showed that the gum Arabic significantly decreased all the viscosity parameters (peak viscosity, final viscosity, break down and setback values) of both starches at all levels of substitution. However, there was no significant effect of gum Arabic on the pasting temperature (72.05°C - 71.85°C) for corn starch and (68.90°C - 68.65°C) for cassava starch. The degree of gel firmness and consistency was higher in corn starch than in cassava starch and the effect of gum addition differed with each starch. The findings from this study indicate that gum Arabic significantly modified the pasting and textural properties of corn and cassava starches due to strong interaction between the gum and the starches. Hence, this property of gum Arabic could be useful in controlling starch retrogradation and determining starch end use functionality.

Differences of Physicochemical Properties Between Chalky and Translucent Parts of Rice Grains

Rice grain chalkiness is an important characteristic,but the difference between chalky and translucent parts in grains is still unclear.Here,we investigated the differences of flour made from the chalky or translucent part of rice grains in three indica and three japonica rice varieties.The chalky flour had significantly lower amylose and protein contents and looser starch granule morphology,and starches in the chalky flour had higher relative crystallinity,higher short chain content but lower long chain content than those in the translucent flour.The water states,determined with nuclear magnetic resonance,differed between the chalky and translucent flour after soaking,cooking and retrograding,and the chalky flour had more bound and free water but less constructural water than the translucent flour.Mostly,the chalky flour had lower viscosity and shorter gel consistency,but higher onset temperature and gelatinization enthalpy than the translucent flour.The results indicated that starch granule morphology would be more indicative than other attributions on pasting and gelatinization properties of chalky and translucent parts of rice grains.

RVA and Farinograph Properties Study on Blends of Resistant Starch and Wheat Flour

Resistant starch （RS） is the undigested starch that passes through the small intestine to the large intestine. As a functional low calorie additive, it has special applications in the food industry. Rapid visco analysis （RVA） and the Brabender farinograph were used to study the pasting properties and the viscoelasticity of blends of RS （RS3 and RS2） and three wheat flours. The wheat flours represented strong gluten wheat （SGW）, intermediate gluten wheat （IGW）, and weak gluten wheat （WGW） flours, at different levels of RS substitution （0, 5, 10, 15, and 20%）. The influence of RS3 on the control wheat flours and RS-wheat flour blends were consistent with those of RS2. The peak, trough, and final viscosities of RS3-wheat flour blends were higher than those of the corresponding RS2-wheat flour blends. The peak, trough, breakdown, final, and setback viscosities ofwheat-RS blends decreased with an increase in resistant starch contents from 0 to 20% in the blends. The 0-20% RS-wheat flour blends were all able to form doughs. The dough development times, dough stabilities, dough breakdown times, and farinograph quality numbers for the RS-wheat flour blends decreased as the RS proportion in the blends increased. The values for RS-SGW flour blends were the highest, followed by RS-IGW and then RS-WGW flour blends. The water absorption values for RS-wheat flour blends and the mixing tolerance index for RS-WGW flour blends were found to increase significantly with an increasing proportion of RS from 0 to 20%, but the mixing tolerance index for RS-SGW and RS-IGW flour blends showed no significant differences amongst the different ratios. Correlation analysis showed that the Farinograph quality number was highly positively correlated with dough breakdown time, dough stability, and dough development time （r= 1.000, 0.958, 0.894）, and highly negatively correlated with the mixing tolerance index （r =-0.890）. Data from this study can be used for the development of dough-based products. It also provides a basis for RS-wheat flour blends and quality evaluation in the food industry.

The Relationship Between Chinese Raw Dumpling Quality and Flour Characteristics of Shandong Winter Wheat Cultivars

Dumpling is one of the most important traditional wheat products in China. Dumpling quality is determined by the characteristics of both flour and filling, thus improvement of flour quality plays an important role in improving dumpling quality. Thirty-nine Shandong winter wheat cultivars and advanced lines sown in Jinan, Shandong Province, China, in the 2008-2009 cropping season were used to determine genetic variation in Chinese raw dumpling quality and its relationship with flour characteristics. Large variations were observed for protein quality parameters in comparison with starch properties. Variation in color of the raw dumpling sheet was broader than that of sensory evaluation parameters of boiled dumpling among tested wheat cultivars, indicating the large influence of filling on dumpling color. Two cultivars, Jimai 20 and Zimai 12, were identified as possessing very good quality of raw dumpling, and 21 cultivars and advanced lines showed good quality. Protein and total starch content influenced the L＊ value of raw dumpling sheets. L＂ value at 0 and 2 h after sheeting were significantly influenced by protein content （r=-0.46 and -0.52, P〈0.01） and total starch content （r=0.55 and 0.57, P〈0.01）, respectively. Flour yellow pigment was significantly corrected with a＊ （r=-0.67 and -0.62, P〈0.01） and b＊ （r=0.87 and 0.84, P〈0.01） value of raw dumpling sheets at 0 and 2 h after sheeting, respectively. Gluten strength parameters such as farinograph mixing tolerance index （MTI, r=-0.55, P〈0.01） were positively associated with appearance. MTI and energy were also significantly and positively correlated with elasticity of raw dumpling, with r=-0.54 and 0.47 （P〈0.01）. The positive relationships between peak viscosity （r=0.51, P〈0.01）, breakdown （r=0.54, P〈0.01）, and smoothness of raw dumpling were also observed. Therefore, it is suggested that breeding programs should give more attention to gluten strength and starch pasting parameters for raw dumpling quality improvement.

Characterization of A-and B-type starch granules in Chinese wheat cultivars

Starch is the major component of wheat flour and serves as a multifunctional ingredient in food industry. The objective of the present study was to investigate starch granule size distribution of Chinese wheat cultivars, and to compare structure and functionality of starches in four leading cultivars Zhongmai 175, CA12092, Lunxuan 987, and Zhongyou 206. A wide variation in volume percentages of A- and B-type starch granules among genotypes was observed. Volume percentages of A- and B-type granules had ranges of 68.4–88.9% and 9.7–27.9% in the first cropping seasons, 74.1–90.1% and 7.2–25.3% in the second. Wheat cultivars with higher volume percentages of A- and B-type granules could serve as parents in breeding program for selecting high and low amylose wheat cultivars, respectively. In comparison with the B-type starch granules, the A-type granules starch showed difference in three aspects：（1） higher amount of ordered short-range structure and a lower relative crystallinity,（2） higher gelatinization onset（To） temperatures and enthalpies（ΔH）, and lower gelatinization conclusion temperatures（Tc）,（3） greater peak, though, and final viscosity, and lower breakdown viscosity and pasting temperature. It provides important information for breeders to develop potentially useful cultivars with particular functional properties of their starches suited to specific applications.

A plastidic ATP/ADP transporter gene, IbAATP, increases starch and amylose contents and alters starch structure in transgenic sweetpotato

A plastidic adenosine triphosphate（ATP）/adenosine diphosphate（ADP） transporter（AATP） is responsible for importing ATP from the cytosol into plastids. In dicotyledonous plants, increasing ATP supply is a potential way to facilitate anabolic synthesis in heterotrophic plastids. In this study, a gene encoding the AATP protein, named Ib AATP, was isolated from sweetpotato（Ipomoea batatas（L.） Lam.）. Transcripts of Ib AATP were predominantly detected in the storage roots and leaves and were induced by exogenous sucrose and subjected to circadian rhythm. Transient expression of Ib AATP in tobacco and onion epidermal cells revealed the plastidic localization of Ib AATP. The overexpression of Ib AATP in sweetpotato significantly increased the starch and amylose contents and led to enlarged starch granules. The IbA ATP-overexpressing plants showed altered fine structure of amylopectin, which contained an increased proportion of chains with a degree of polymerization（DP） of 10–23 and a reduced number of chains with a DP of 5–9 and 24–40. In addition, starch from the transgenic plants exhibited different pasting properties. The transcript levels of starch biosynthetic genes, including Ib AGP, Ib GBSSI, Ib SSIIV, and Ib SBE, were differentially regulated in the transgenic plants. These results revealed the explicit role of Ib AATP in the starch biosynthesis of sweetpotato and indicated that this gene has the potential to be used to improve starch content and quality in sweetpotato and other plants.

Electroneutral Quaternization/Sulfosuccination for Alleviating the Adverse Effect of Paste Aging on the Properties of Corn Starch Film

For the purpose of alleviating the adverse effect of paste aging on the properties of corn starch film, a series of electroneutrally quaternized/sulfosuccinylated starches（EQSS） with different degrees of substitution（DS） were synthesized via the quaternization/sulfosuccination of acid-thinned corn starch（ATS） by varying the amounts of N-（3-chloro-2-hydroxypropl） trimethylammonium chloride, maleic anhydride, and sodium hydrogen sulfite. The influence of paste aging on the properties of starch film cast from heat-induced starch paste was investigated and the properties were explored in terms of tensile strength, elongation, work at break, degree of crystallinity, and flex-fatigue resistance. The experimental results showed that the paste ageing generated adverse influence on the elongation, work at break, and flex-fatigue resistance of starch film. Further experiments showed that electroneutral quaternization/sulfosuccination of starch were able to alleviate the negative effect of paste ageing on the elongation, work at break, and flex-fatigue resistance, thereby obviously enhancing the elongation, work at break and flex-fatigue resistance, and thus reducing the drawback of brittleness. The enhancement depended on the amounts of the substituents introduced. With the increase in DS value, the elongation and work at break as well as flex-fatigue resistance continuously rose, whereas the tensile strength gradually reduced.

Bioactive profile of borno brown Vigna unguiculata grains as influenced by pre-harvest synthetic chemicals

This study investigated the impact of pre-harvest synthetic chemical treatments on the post-harvest bioactive contents,pasting,colour,and thermal properties of borno brown V.unguiculata(L.)Walp grains.Seeds of borno brown V.unguiculata(L.)Walp was planted on an already ploughed,harrowed and ridged plot of land with a portion cultivated as organic and another non-organic.After 90 days,mature grains were harvested and analyzed using standard procedures.Results showed that a total of 44.33 g bioactive compounds/100g grain was present in the organic borno brown V.unguiculata grains whereas,20.56 g bioactive compounds/100g grain was present in the non-organic(control).The identified bioactive compounds in the organic grains included[heneicosane(4.50g/100g grain)];[12-Methyl-E,E-2,13-octadecadien-1-ol(4.09/100g grain)];[3-(2-Hydroxy-6-methylphenyl)-4(3H)-quinazolinone(7.40 g/100g grain)];[Methaqualone(9.08 g/100g grain)].The non-organic contained[heneicosane(4.07g/100g grain)];[3-(2-Hydroxy-6-methylphenyl)-4(3H)-quinazolinone(5.09 g/100g grain)];[Methaqualone(10.61 g/100g grain)].Flavonoids,alkaloids,total phenolic,2,2-diphenyl-1-picryl-hydrazl(DPPH)and ferric ion reducing antioxidant power(FRAP)contents of the organic grains were 19 mgRE/100g,3.40 mg/100g,1550 mgGAE/100g,2840μmolTEAC/100g,and 20.08 mmol Fe^(2+)/100g,respectively.The non-organic grains had flavonoids(11.31 mgRE/100g),alkaloids(1.86 mg/100g),total phenolic(1110 mgGAE/100g),DPPH(1779μmolTEAC/100g)and FRAP(12.24 mmol Fe^(2+)/100g).The peak viscosity of 111.52 RVU,final viscosity(141.25 RVU)and pasting temperature(82.01℃)were obtained for the organic grains while non-organic had peak viscosity of 93.10RVU,final viscosity(95.20 RVU)and pasting temperature(80.10℃).The colour parameters L^(*),a^(*),b^(*)and ΔE were 73.10,0.68,14.47 and 12.98 for the organic and 84.25,0.30,21.10,and 0.00,respectively for non-organic grains.The thermal property showed enthalpy(ΔH)and peak temperature(T_(p))of 3.12 J/g and 78.25℃ for organic,and 2.14 J/g and 76.28℃ for non-organic grains,respectively.Phenolic compounds profile showed that organic grains were richer in epicatechin,gallic acid,ferulic acid,chlorogenic acid,4-hydroxy benzoic acid,and catechin.Organic grains showed significant(p<0.05)superiority in bioactive compounds,phytochemicals,and antioxidants over non-organic grains.Good pasting properties of the organic grains showed that it could function as a food thickener.Organic borno brown V.unguiculata grains are rich in health-promoting compounds and could,therefore,be used as an ingredient in the development of functional foods.

Influence of co-solvent hydroxyl group number on properties of water-based conductive carbon pastes

A series of water-based conductive carbon pastes were prepared by wet ball milling, followed by vacuum defoaming using isopropyl alcohol, propylene glycol or glycerin as co-solvents. Screen printing was then used to prepare conductive patterns. To determine the influence of co-solvent hydroxyl group number on the properties of water-based conductive carbon pastes, the rheological properties of the pastes and the surface morphologies and conductivities of the printed patterns were characterized. The results show that paste viscosity increased with the number of hydroxyl groups and the latter also affected thixotropy. In addition, the boiling points and surface tensions of the co-solvents increased consistently with hydroxyl group number, affecting the hydrodynamic flow. The conductive carbon paste created using propylene glycol as a co-solvent was the best for screen printing because of its weak coffee-ring effect and appro- priate rheological properties, resulting in a smooth coating surface and uniform deposition of the fillers. The resistivity of the pattern printed using paste PG, containing the closest packing of conductive carbon black particles, was 0.44 Ω cm.

Probing nutritional and functional properties of salted noodles supplemented with ripen Banana peel powder

Banana peel is appreciated for higher dietary fiber, phenolics, flavonoid contents, and minerals (particularly iron, calcium, and potassium), despite being a waste product. After drying, it can be processed into powder/flour to be combined with wheat flour (WF) for development of value-added products. In this study, we substituted WF with banana peel powder (BPP) at supplementation rates of 5, 10, and 15%, and evaluated their suitability to develop salted noodles. The results showed that the composite flour with 15% BPP had significantly higher protein, ash, and crude fiber content as compared to control. Higher antioxidant capacity was observed in composite flour noodles: total phenolics content (TPC), total flavonoid content (TFC), ferric reducing power (FRAP) and DPPH reducing power were increased up to 278, 260, 143 and 13 percent respectively in the noodles containing 15% BPP as compared to control (100% WF). On the other hand, values for viscosity decreased up to 22% with addition of BPP in WF. Furthermore, water absorption capacity and cooking losses were increased up to 15 and 13 percent respectively with 15% BPP incorporation in WF. Results for sensory evaluation demonstrated that noodles with 10% BPP scored highest for sensory profile.