Characterization of starches isolated from Mexican pulse crops: Structural, physicochemical, and rheological properties

This work aimed to characterize and compare the physicochemical properties of four pulse starches: bean, chickpea, lentil, and pea. Chemical proximate analysis, elemental composition, morphological grain characterization, crystalline structure, thermal analysis, FTIR analysis, and pasting properties were conducted. The proximate analysis shows that these starches have low fat, mineral, and protein content but high amylose values ranging from 29 to 36 % determined by colorimetry. Despite the high amylose content, the starches did not exhibit the typical behavior of an amylose-rich starch, with high peak viscosity and low breakdown and setback. It was found that this behavior was likely due to the large granule size of the ellipsoidal, spherical, and kidney-shaped granules and the high content of some minerals such as Na, Mg, K, Fe, Mn, P, and Si. The study also found that all pulse starches simultaneously contain monoclinic and hexagonal crystals, making them C-type starches. The findings were verified through the Rietveld analyses of X-ray diffraction patterns and differential scanning calorimetry, in which bimodal endothermic peaks evidenced both types of crystals being gelatinized.

Antimicrobial activity of geranium (Pelargonium graveolens) essential oil and its encapsulation in carioca bean starch ultrafine fibers by electrospinning

Geranium (Pelargonium graveolens) is known for being an aromatic plant rich in bioactive compounds with antibacterial properties. In this study, geranium essential oil (GEO) was extracted and encapsulated in ultrafine bean starch fibers produced by electrospinning as an antibacterial agent. GEO revealed a composition rich in volatile compounds, including citronellol, cis-geraniol, β-linalool, citronellyl formate, and linalool formate. In its free form, GEO exhibited high antibacterial activity against pathogenic bacteria strains (L. monocytogenes, S. aureus, and E. coli). The bean starch fibers, produced with and without the addition of GEO, were uniform and continuous, with an average diameter ranging from 249 to 373 nm. Confocal analysis indicated a uniform distribution of GEO in the fibers, with a loading capacity of 54.0 %, 42.9 %, and 36.5 % for 20 %, 30 %, and 40 % GEO concentrations, respectively. Remarkably, fibers containing 40 % GEO showed a significant reduction in tested bacteria (L. monocytogenes, S. aureus, and E. coli), suggesting promising applications in preventing losses and extending the shelf life of food through active packaging.

Fabrication and characterization of dual-functional porous starch with both emulsification and antioxidant properties

Starchy materials with good antioxidant, emulsification and adsorption properties have potential applications in industry. To improve these properties, a Dual-functional porous starch was prepared through one-pot synthesis. In this case, octenyl succinic anhydride (OSA) and syringic acid (SA) were selected to modify the porous starch (PS) by esterification, with subsequent signals recorded by 1H NMR at 1.2 ppm and FT-IR at 1743 cm-1, indicating the formation of Dual-functional porous starch grafted by OSA and SA. N2 adsorption analysis further proved that the porous structure (2.9 m2g-1) was still maintained after modification. This was followed by measurements of droplet size distribution (34.18 ± 3.80 μm), zeta potential (-39.62 ± 1.89 mV) and emulsion index (85.10 ± 1.76 %), all of which indicated good emulsifying capacity. Meanwhile, results of radical scavenging assay proved that the Dual-functional porous starch had considerable antioxidant properties due to the introduction of SA groups. Besides, the Dual-functional porous starch also showed good resistance to digestion. These findings not only provide a novel strategy for constructing multi-functionalized starchy materials, but also open up potential applications of starch in the food and pharmaceutical industries.

Physicochemical Properties of Granular and Gelatinized Lotus Rhizome Starch with Varied Proximate Compositions and Structural Characteristics

As a traditional and popular dietary supplement, lotus rhizome starch (LRS) has health benefits for its many nutritional components and is especially suitable for teenagers and seniors. In this paper, the approximate composition, apparent amylose content (AAC), and structural characteristics of five LRS samples from different regions were investigated, and their correlations with the physicochemical properties of granular and gelatinized LRS were revealed. LRS exhibited rod-shaped and ellipsoidal starch granules, with AAC ranging from 26.6% to 31.7%. LRS-3, from Fuzhou, Jiangxi Province, exhibited a deeper hydrogel color and contained more ash, with 302.6 mg/kg iron, and it could reach the pasting temperature of 62.6 °C. In comparison, LRS-5, from Baoshan, Yunnan Province, exhibited smoother granule surface, less fragmentation, and higher AAC, resulting in better swelling power and freeze-thaw stability. The resistant starch contents of LRS-3 and LRS-5 were the lowest (15.3%) and highest (69.7%), respectively. The enzymatic digestion performance of LRS was positively correlated with ash content and short- and long-term ordered structures but negatively correlated with AAC. Furthermore, the color and network firmness of gelatinized LRS was negatively correlated with its ash content, and the retrograde trend and freeze-thaw stability were more closely correlated with AAC and structural characteristics. These results revealed the physicochemical properties of LRS from different regions and suggested their advantages in appropriate applications as a hydrogel matrix.

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Thermal processing remains the key processing technology for food products. However, there are some limitations for thermal processing such as loss of sensory and nutritional quality. Furthermore, nowadays consumers are looking forward for fresh like products which are free from chemical preservatives, yet having longer shelf life. Thus, alternative processing techniques are gaining popularity among food processors to replace conventional thermal processing keeping nutritional quality, sensory attributes and food safety in mind. The alternative processing techniques such as ultrasound, gamma irradiation, high pressure processing and microwave treatment causes several modifications (structural changes, effects on swelling and solubility index, gelatinization behaviour, pasting or rheological properties, retrogradation and cooking time) in physicochemical and functional properties of pulse starches which offers several advantages from commercial point of view. This review aims to summarize the effect of different alternative processing techniques on the structure, solubility, gelatinization, retrogradation and pasting properties of various pulse starches.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-022-05557-3.

Morphological, textural analysis and freeze-thaw stability of starches from legume grow in Cameroon

Starches from some legume grown in Cameroon were evaluated for their granule structure and size, turbidity, firmness and gel strength, thermal and freeze-thaw properties. Amylose contents were in the range of 26.21%-44.85%. Morphological analysis of the starch granules showed bimodal distribution, multiple sizes and shapes from small spherical to the bigger kidney shape. Significant differences were observed among starch in light transmittance, firmness and gel strength. The thermal parameters of starches were evaluated using differential scanning calorimeter and significant differences were observed. The peak gelatinisation temperature was positively correlated to starch granule size but the amylose content showed no evidence of their impact on legume starch properties studied. The data reported can be useful to facilitate the selection of variety of legume and conditions closer to the desired application.

Structure and physicochemical properties of low digestible Euryale ferox Salisb. seed starch

BACKGROUND

Euryale ferox Salisb. is widely grown in China and Southeast Asia as a grain crop and medicinal plant. The composition, morphology, structure, physicochemical properties, thermal properties, and in vitro digestibility of North Euryale ferox seeds starch (NEFS), hybrid Euryale ferox seeds starch (HEFS), and South Euryale ferox seeds starch (SEFS) were studied.

RESULT

Of the varieties that were studied, the amylose content of NEFS (23.03%) was the highest. Starch granules of each variety were smooth, sharp, small, and had an average diameter of 2 μm. All three varieties were A-type crystals with crystallinity ranging from 26.42% to 28.17%. The degree of double helix and the short-range order ranged from 1.9006 to 2.5324 and 1.4294 to 1.6006, respectively. The high proportion of C1 region in NEFS (17.74%) and HEFS (17.66%) were found. Thermodynamic properties in North Euryale ferox seeds included the highest onset temperature (T_o ) (71.43 °C), peak temperature (T_p ) (76.60 °C), conclusion temperature (T_c ) (82.77 °C), enthalpy of gelatinization (ΔH) (12.64 J g^-1 ), and peak viscosity (1514 mPa·s). All three varieties maintained a low level of in vitro digestibility, with the highest resistant starch (RS) content (29.57%), the lowest rapidly digestible starch (RDS) content (27.07%), and the slowest hydrolysis kinetic constant (0.0303) in NEFS.

CONCLUSION

The results revealed that the low digestibility of NEFS was attributable to compact granules, high crystallinity, high degree of order, and strong thermal stability. These digestive, physicochemical, and thermodynamic properties provide information for the future application of Euryale ferox seed starch in the food industry. © 2022 Society of Chemical Industry.

Non-conventional starches isolated from agronomic-improved beans (Phaseolus vulgaris L.): a study of their structure and physicochemical properties

BACKGROUND

Non-conventional starch sources are promising alternative food ingredients. Different bean varieties with agronomic improvements are constantly being developed and cultivated in the Northwestern Argentinean region (NOA) to increase yields and obtain high-quality seeds. However, the main attributes of their starches have not been studied. In this work, starches from four agronomic-improved bean cultivars were isolated and their structure and physicochemical properties were evaluated.

RESULTS

High-purity starches were obtained, as shown by their low protein and ash content. Starch granules presented smooth surfaces with spherical to oval shapes, with a marked 'Maltese cross' and heterogeneous sizes. Their amylose content revealed a mean value of 318 g kg^-1 and all presented resistant > slowly digestible > rapidly digestible starch fractions. Their Fourier transform infrared spectra were similar and X-ray diffraction analysis showed a C_A -type pattern in all cases despite their different sources. Among thermal properties, Escarlata starch showed the lowest gelatinization peak temperature (69.5 °C) and Anahí starch the highest (71.3 °C). Starch pasting temperature varied from 74.6 to 76.9 °C, whereas peak viscosity and final viscosity showed a similar tendency, with Leales B30 < Anahí < Escarlata < Cegro 99/11-2 and Leales B30 < Anahí = Escarlata < Cegro 99/11-2, respectively.

CONCLUSION

This study provides the basis for a better understanding of the characteristics of agronomic-improved NOA bean starches, enabling their use in product formulation as an alternative to starches from conventional sources. © 2023 Society of Chemical Industry.

Optimisation of the techno-functional and thermal properties of heat moisture treated Bambara groundnut starch using response surface methodology

This work optimised the techno-functional and thermal properties of heat moisture treated Bambara groundnut starch (BGS). A central composite rotatable design (Design-Expert software v8.0.1.0) comprising two independent factors of temperature and time was used. Extracted BGS were subjected to heat-moisture treatment (HMT) at 80-120 °C for 30-90 min at different moisture levels of 15% (HMT 15-BGS), 25% (HMT 25-BGS) and 35% (HMT 35-BGS). The optimum HMT conditions for BGS were found to be 80 °C for 30 min (HMT 15), 105.74 °C for 30 min (HMT 25), and 113.16 °C for 30 min (HMT 35). The desirability values of the obtained optimum conditions were 0.63 (HMT 15) and 1.00 (HMT 25 and 35). In HMT 35-BGS, water absorption capacity was significantly affected by the quadratic effect of temperature and time. In contrast, solubility was significantly affected by the linear effect of time and the quadratic effect of temperature. Temperature and treatment time had no significant effect (p ≥ 0.05) on the differential scanning calorimetry thermal properties of HMT 15, 25 and 35-BGS. Scanning electron micrographs of optimised BGS showed round and oval-shaped starch granules ranging from 4.2 to 4.7 mm (width) and 10 μm for length. Unmodified and optimised HMT-BGS showed characteristic FTIR bands linked with common starches. All BGS samples displayed multiple vibrations in the region below 1000 cm^-1 due to the skeletal vibrations of the glucose pyranose ring.

Neolithic dental calculi provide evidence for environmental proxies and consumption of wild edible fruits and herbs in central Apennines

Looking for a biological fingerprint relative to new aspects of the relationship between humans and natural environment during prehistoric times is challenging. Although many issues still need to be addressed in terms of authentication and identification, microparticles hidden in ancient dental calculus can provide interesting information for bridging this gap of knowledge. Here, we show evidence about the role of edible plants for the early Neolithic individuals in the central Apennines of the Italian peninsula and relative cultural landscape. Dental calculi from human and animal specimens exhumed at Grotta Mora Cavorso (Lazio), one of the largest prehistoric burial deposits, have returned an archaeobotanical record made up of several types of palaeoecological proxies. The organic fraction of this matrix was investigated by a multidisciplinary approach, whose novelty consisted in the application of next generation sequencing to ancient plant DNA fragments, specifically codifying for maturase K barcode gene. Panicoideae and Triticeae starches, together with genetic indicators of Rosaceae fruits, figs, and Lamiaceae herbs, suggested subsistence practices most likely still based on wild plant resources. On the other hand, pollen, and non-pollen palynomorphs allowed us to outline a general vegetational framework dominated by woodland patches alternated with meadows, where semi-permanent settlements could have been established.

Physiochemical and thermal characterisation of faba bean starch

The structure and physicochemical properties of starch isolated from the cotyledon and hull of faba beans and from wheat (as reference) were examined using 16 different methods. The amylose content in faba bean cotyledon and hull starch was 32% and 36%, respectively, and that in wheat starch was 21%. The faba bean cotyledon and hull starch were structurally alike both displaying C-polymorphic pattern, a similar degree of branching and similar branch chain length distributions. Wheat starch had a significantly greater prevalence of short amylopectin chains (DP < 12) and a higher degree of branching. Granules in both faba bean starches exhibited surface cracks and were more homogenous in size than the smoother wheat starch granules. Gelatinisation temperature was higher for the faba bean starches, likely as an effect of high amylose content and longer starch chains delaying granular swelling. Cotyledon starch produced pastes with the highest viscosities in all rheological measurements, probably owing to larger granules. Higher prevalence of lipids and resistant starch reduced the viscosity values for hull starch. For all starches, viscosity increased at faster heating rates. During the rheological analyses, the samples were exposed to different instruments, heating rates and temperatures ranges, differing from standard rheological procedures, which could help predict how different processing techniques effect the final starch textures.

Graphical abstract

Composition, morphology and physicochemical properties of starches derived from indigenous Ethiopian tuber crops: A review

Starch is a key food ingredient that can be extracted from roots, tubers, cereals, legumes and used in a variety of industrial applications. The issue of starch has received considerable critical attention. Most conventional sources of starch are being overexploited, it is necessary to investigate new botanical sources of starch to relieve pressure on traditional sources. Indigenous Ethiopian tuber crops can represent unexploited sources of starch with interesting characteristics in terms of potential uses as starch-based foods. It comes in a variety of shapes, sizes and properties allowing for a wide range of applications with high technological value in both the food and non-food industries. Compared to common starches, these starches have far fewer studies on their food and industrial applications. In the future, tubers grown Ethiopia could become another source of starch for the processor. This review summarizes current knowledge about the composition, structure, and physicochemical properties of Ethiopian tubers starches, intending to recommend future research to improve their use in the food industry. In the future, more in-depth work will be needed to reveal the mechanism of modification involved for structural change to use these starches for different purposes.

Composition, Physicochemical Properties, and Uses of Acorn Starch

The major component of acorn is starch, which may amount up to 55% of the dry weight. Lack of systematic knowledge on acorn starch greatly hinders the further development of acorns as sustainable crops. This review aims to summarize the current knowledge of the isolation, chemical composition, physicochemical properties, and uses of acorn starches and to provide future research directions. The amylose content of the acorn starches is reported to vary in the range of 20–39%. Moisture content, lipid, ash, and protein contents of the acorn starches have been reported varying from 2.20 to 15.50%, 0.23 to 2.64%, 0.01 to 1.41%, and 0.01 to 6.7%, respectively. Thermal and pasting properties that have usually been determined using differential scanning calorimeter (DSC) and rapid viscoanalyzer (RVA) are also discussed in this article. Acorn starch has great potential for various food and nonfood applications due to the unique structural and functional features.

Characterization of underutilized root starches from eight varieties of ramie (Boehmeria nivea) grown in China

Ramie root is an underutilized starch source. In this study, eight ramie varieties were investigated for starch properties. Starch content ranged from 18.6% to 50.1% in dry root. Starches from different varieties showed similar morphology including ellipsoidal, spherical and truncated granules with size D[4,3] from 10.1 to 14.1 μm. Starch had amylose content from 20.8% to 28.5%. All ramie varieties had B-type starches with relative crystallinity from 24.8% to 27.1%, ordered degree from 0.724 to 0.897 and lamellar thickness from 9.1 to 9.6 nm. Starches had gelatinization peak temperature from 70.5 to 73.8 °C and enthalpy from 14.9 to 15.8 J/g. Starches had swelling power and water solubility from 27.9 to 31.9 g/g and from 11.7% to 15.5%, respectively, at 95 °C, and exhibited different pasting properties with breakdown viscosity from 36 to 377 mPa s and setback viscosities from 1295 to 1863 mPa s. Starch pastes exhibited pseudoplastic behavior and different rheological properties. Native, gelatinized and retrograded starches had resistant starch from 81.7% to 83.9%, from 1.7% to 5.1% and from 5.6% to 13.3%, respectively. The eight varieties were divided into 3 groups according to starch properties. This study is helpful for selecting suitable ramie variety as starch source.

Addition of chickpea markedly increases the indigestible carbohydrate content in semolina pasta as eaten

BACKGROUND

There is a growing interest in increasing dietary fiber (DF) consumption because of the health benefits associated with this nutrient. Pulses are considered a good source of non-digestible carbohydrates. The aim of this study was to investigate the possibility of substituting semolina with chickpea flour to increase indigestible carbohydrate content without altering the texture of the pasta.

RESULTS

Pasta was prepared by extruding semolina-chickpea blends. The protein and DF content in the cooked pasta increased with the chickpea level, with an important contribution of resistant starch (RS) to the DF values. The optimum cooking time decreased as the chickpea content increased, which was related to the degree of starch gelatinization of the raw pasta. The in vitro digestible starch content decreased with the chickpea substitution level, concomitant with the increase in RS content. In general, the texture of the chickpea-containing pasta was similar to that of semolina pasta.

CONCLUSIONS

Pending acceptability studies on these pastas may grant their promotion as good fiber sources, probably helpful in the fight against obesity and diet-related non-communicable diseases. © 2020 Society of Chemical Industry.

Comparison of physicochemical and mechanical properties of edible films made from navy bean and corn starches

BACKGROUND

Recently, there has been a great interest in developing new applications of edible dry beans (Phaseolus vulgaris L.). The utilization of starch, comprising the major component of dry bean seeds, for the preparation of edible films has just emerged.

RESULTS

In the present study, we chose navy bean as a model dry bean source, isolated its starch component, prepared edible films with different formulations (35 and 40 g L^-1 ), and compared these with the films made using isolated and commercial corn starches. Sunflower oil at 10 g L^-1 was dispersed into film-forming solution to design composite films. The water vapor barrier property, mechanical properties and microstructure of starch films from navy bean and corn were studied to evaluate their potential for use in food packaging. All of the films had smooth and uniform surface and were transparent.

CONCLUSION

Navy bean starch film showed physicochemical and mechanical properties comparable to corn starch films, and the addition of sunflower oil could further improve the water vapor barrier and mechanical properties of films. The findings obtained in the present study demonstrate the potential of using navy bean starch to prepare edible films. © 2020 Society of Chemical Industry.

Physicochemical properties of a new starch from ramie (Boehmeria nivea) root

A new starch was isolated from ramie root, and its physicochemical properties were investigated. Ramie dry root contained 45.9% starch. Starch had truncated, ellipsoidal, and spherical granule shapes with size from 7 to 30 μm and D[4,3] about 14.1 μm. Starch contained 38.9% apparent amylose content and 22.4% true amylose content, exhibited B-type crystallinity, and had 26.6% relative crystallinity, 0.82 ordered degree, and 9.2 nm lamellar thickness. Starch had 71.8 °C gelatinization peak temperature and 15.6 J/g gelatinization enthalpy, and exhibited 31.4 g/g swelling power and 17.1% water solubility at 95 °C. Starch had peak, hot, breakdown, final, and setback viscosities at 3048, 2768, 279, 4165, and 1397 mPa s, respectively, and showed peak time at 4.36 min and pasting temperature at 75.0 °C. The native, gelatinized, and retrograded starches contained 15.1%, 94.0%, and 86.5% rapidly digestible starch and 83.3%, 4.0%, and 10.7% resistant starch, respectively. Compared with potato and rice starches, ramie starch was somewhat similar to potato starch but significantly different from rice starch in starch component, crystalline structure, and functional properties. Therefore, ramie starch exhibited the potential to be used as a thickening agent, resistant-digesting food additive, and alternative to potato starch in food and nonfood industries.

Effects of heat-moisture treatment on the thermal, functional properties and composition of cereal, legume and tuber starches-a review

Several methods are currently employed in the modification of starch obtained from different botanical sources. Starch in its native form is limited in application due to retrogradation, syneresis, inability to withstand shear stress as well as its unstable nature at varying temperatures and pH environment. Modification of starch is therefore needed to enhance its food and industrial application. A primary and safe means of modifying starch for food and industrial use is through hydrothermal methods which involves heat-moisture treatment and annealing. Heat-moisture treatment (HMT) is a physical modification technique that improves the functional and physicochemical properties of starch without changing its molecular composition. Upon modification through HMT, starches from cereals, legumes and tuber crops serve as important ingredients in diverse food, pharmaceutical and industrial processes. Although changes in starch initiated by HMT have been studied in starches of different plant origin, this work further provides insight on the composition, thermal and functional properties of heat-moisture treated starch obtained from cereals, legumes and tuber crops.

In Vitro Starch Digestibility and Estimated Glycemic Index of Mung Bean (Vigna radiata L.) as Affected by Endogenous Proteins and Lipids, and Exogenous Heat-Processing Methods

The aim of this study was to investigate the in vitro starch digestibility and estimated glycemic index (eGI) of mung bean (Vigna radiata L.) as affected by endogenous proteins and lipids, and exogenous heat-processing methods. Results showed that the in vitro starch digestibility and eGI were significantly increased after the removal of protein, lipid, or both (P < 0.05). Moreover, the effects of endogenous proteins and lipids on the in vitro starch digestibility and eGI of mung bean followed the order: both protein and lipid removal > protein removal > lipid removal. In addition, heat-processing could make the slowly digestible starch and resistant starch convert to the rapidly digestible starch. The effects of different exogenous heat-processing methods on in vitro starch digestibility and eGI in the present study showed the following order: germination combined with cooking > high-pressure cooking > extrusion cooking > ordinary cooking. This study provided a crucial reference for the human with potential hyperglycemia to choose mung bean treated with ordinary cooking and without further protein and/or lipid removal.

Technological Properties of Acetylated Pigeon Pea Starch and Its Stabilized Set-Type Yoghurt

The behaviour of graded acetylated pigeon pea starch during heat processing was evaluated in addition to the corresponding effect of their incorporation at 1.5% (w/v) as a stabilizer in set-type yoghurt. Acetylated starch possessed higher solubility and swelling power than native starch under the temperature regimes considered. Addition of acetylated pigeon pea starch as a stabilizer in yoghurt had positive influence on the water holding capacity (7.7% to 10.4% compared to 13.3% in yoghurt stabilized with native pigeon pea starch) and whey syneresis (approximately 15%, 12%, and 8% increase observed in yoghurt with acetylated pea starch compared to 47% in yoghurt with native pea starch stabilizer) at the end of a 28-day cold storage period. In addition, pea starch-stabilized yoghurt possessed an enhanced sensory attribute (firmness), and compared favourably with gelatin-stabilized yoghurt in terms of overall acceptability. Thus, acetylated pigeon pea starch exhibited improved physicochemical properties and showed usefulness as a stabilizer in yoghurt because it enhanced the physicochemical, storability, and sensorial quality, while improving the body and texture of the product.

Morphological, physico-chemical and functional properties of underutilized starches in China

In this study, starches were isolated from different non-conventional sources (acorn, black wheat, buckwheat, coix seed, jiaoyu, kuzhu, longya lily, and naked oat) cultivated in China, and their morphological, physico-chemical, and functional properties were analyzed. Among isolated starches, significant differences (p < 0.05) were observed in morphology, pasting, crystallinity, physico-chemical, and functional properties. After a comparison with commercial corn starch, all these isolated starches presented promising and unique characteristics. The XRD profile of isolated starches presented A-type (naked oat, buckwheat, coix seed, and black wheat), B-type (longya lily, acorn and jiaoyu) and C-type (kuzhu) polymorphic structures. SEM analysis revealed that the starches isolated from different sources showed distinct shapes exclusively globular, elliptic, and polygonal shapes. The high viscosity of jiaoyu and kuzhu starch pastes can be utilized to have an advantage in instant soups and sauces. Hence, the present study will improve the scientific basis on starches from different non-conventional sources, facilitate their utilization in a variety of applications.

Starch characterization of commercial extruded dry pet foods

Starches provide an effective energy source for dogs and cats and can affect health according to its inclusion and extent of digestion. The starch fraction that escapes small intestine (SI) digestion is called resistant starch (RS) and is desirable due to its prebiotic function. Starch is not an essential nutrient for dogs and cats and thus is not reported on commercial pet food labels. Hence, the objective of this work was to characterize starches in commercial pet foods. The top five pet food companies by sales were selected to represent U.S. pet foods, which were divided into four strata with a sampling frame of 654 foods: dog grain based (372 foods), dog grain free (71 foods), cat grain based (175 foods), and cat grain free (38 foods). Five random foods within each stratum were purchased (20 total). Starch analyses (total starch, resistant starch, and starch cook), as well as nutrient analyses were conducted on all foods. Total starch, RS, and starch cook means were compared using a two-group Z-test on dog vs. cat and grain-based (GB) vs. grain-free (GF) diets, and differences were considered significant at a P < 0.05. Total starch was higher (P < 0.05) in dog than cat food, and starch cook was greater (P < 0.05) in GF diets. A regression analysis showed that nitrogen-free extract was a good predictor of total starch. Resistant starch was low and not different among groups. A post hoc test showed that a total sample size of at least 28 diets per group would be required to detect differences in RS between GF and GB diets, if one exists.

Moth bean starch (Vigna aconitifolia): isolation, characterization, and development of edible/biodegradable films

In the current work, moth bean starch was separated from the moth bean seeds which were cultivated in the semi arid regions of Haryana and Rajasthan, India using alkali treatment technique and characterized. Isolated and purified moth bean starch comprised (12.89-20.37%) amylose, 0.8% protein, 0.4% ash, swelling index and solubility were 10.8-14.7% and 6.4-9.8% respectively. For wrapping application, starch was modified using citric acid as cross linking agent (1-7% w/w of total starch) and film was made using casting method, and investigated the influence of citric acid on the functional properties of the films such as moisture content, solubility, swelling index, water vapor permeability and mechanical property. Significant difference in the functional properties among native and modified moth bean starch films was noticed. Interactions among starch chains due to cross linking in the modified starch films were reported using FTIR spectra. Surface micrographs of both purfied starch granules and films were studied using scanning electron microscopy. From the outcomes, it was exhibited that obtained starch granules has range large to small size with distorted cylinder and oval shapes. While cross linked starch films showed compact, slightly rough and homogeneous surface. Tested modified moth bean starch films containing citric acid (CA) and sorbitol were utilized as wrapping films to improve the shelf life of fresh lemon. Outcomes showed that the film contains 5% CA could be most promising wrapping materials for lemon that enhanced the shelf life of lemon additionally up to 12 days.

Viscoelastic and Textural Characteristics of Gels Obtained from Potato Starch Roasted under Several Temperature-Time Conditions

The influence of roasting conditions on the potato starch (PS) composition, solubility, crystallinity, gel-forming thermal profiles, and texture of the corresponding gels was studied. Thermorheological testing of roasted starches with (RPS) and without (RPSI) the soluble fraction was conducted on a stress-controlled rheometer. Texture profile analysis (TPA) was used to determine the RPS final gel texture. Solubility tests showed equivalent effects of starch roasting for samples treated at 190°C for 8 h (RPS190-8), 210°C for 6 h (RPS210-6), and 230°C for 4 h (RPS230-4). The apparent amylose content of RPS linearly increased with the decreasing degree of crystallinity. Elastic (G′) and viscous (G″) properties of RPS depended markedly on apparent amylose content and crystallinity. G′gel values of roasted starches linearly increased with the amylose content suggesting a promotion of the amylose breakdown with roasting temperature. Gels prepared with RPS roasted between 120 and 170°C exhibited intermediate strength and fully thermal reversible features. Roasting between 190 and 210°C favoured strong and fully thermal reversible gels. Although RPS230-4 gels exhibited similar strength to RPS190-8 and RPS210-4, no fully thermal reversible gels were obtained. The soluble fraction removal led to a drop the RPSI gels strength with increasing roasting temperature. No water syneresis was identified for RPS gels during one-week ageing, except for RPS230 gels. Relationships between textural parameters from TPA and viscoelastic gel properties determined by rheology were established.