Article

Quality Traits and Popping Performance Considerations for Popcorn (Zea mays Everta)

Taylor & Francis
Food Reviews International
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Abstract

Popcorn is a snack food with significant commercial popularity. Popcorn popping mechanics can be described by a series of polymeric transformations. The most important quality traits for popcorn are expansion volume and “eatability” factors including unpopped kernels, hull dispersion, and the color, texture, and flavor of popped flakes. Popcorn quality depends on both intrinsic factors, such as hybrid selection, kernel conditioning, and kernel physiochemical attributes, and extrinsic variables including popping method and ingredient additives. Developing new technologies and establishing new quality attributes for popcorn may help to further increase consumer liking and consumption.

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... Popping quality is defined by the component traitstotal flake volume (TFV), popping expansion volume (PEV), and popping rate (PR). 5 Studies of sensory attributes (texture and taste) of popcorn indicated that taste, aroma, reduced hulls, kernel color and size, and number of flake appendages of butterfly popcorn flakes were the major factors influencing consumer acceptance. It was not simply a case of preferring mushroom or butterfly flakes. ...
... Various factors, including kernel sphericity, moisture content, density, pericarp thickness, zeins (⊍-zeins and γ-zeins) in endosperm protein and starch properties, were reported to affect popping quality significantly. 5 Within the popcorn-breeding pipeline, due to prolonged emphasis only on popping quality by the breeders, the popcorn germplasm generally exhibits inferior agronomic traits. 8 However, the recent development of quality protein popcorn (QPP), with enhanced lysine signifies rejuvenated research efforts in popcorn to expand the market value and utilization spectrum through biofortification. ...
... The popping quality measurements were performed in three replications per plot on randomly selected 100 kernels per replication. Total flake volume (TFV), popping expansion volume (PEV), and popping rate (PR) were estimated as described by Sweley et al. 5 The expressions for popping quality traits are as follows: ...
Article
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BACKGROUND Popcorn is the most popular specialty maize and it makes a significant contribution to the Indian and global economies. Despite perfect exploration of heterosis in field corn, progress in popcorn breeding remains constrained due to its narrow genetic base, leading to a significant dependence on imports. In this study, 15 landrace‐ and population‐derived inbreds from temperate and tropical germplasm were crossed with five testers, which are the parents of superior popcorn hybrids, in a line × tester mating design. RESULTS Significant variation was observed in popping quality and agronomic traits among crosses evaluated across three locations representing diverse maize‐based agro‐climatic zones in India. Additive genetic variance governed the traits related to popping quality, whereas dominance variance was responsible for the agronomic traits. In addition to significant heterosis specific to certain traits, we identified promising crosses that exhibited superior performance in both popping quality and grain yield (GY). The genotype + genotype × environment (GGE) biplot methodology identified PMI‐PC‐104 and PMI‐PC‐101 as the best discriminating testers for popping quality traits and Dpcl‐15‐90 for GY. Lines PMI‐PC‐205, PMI‐PC‐207, and PMI‐PC‐209 were the best general combiners for popping quality traits and GY. The heterotic groups identified based on GGE‐biplots and the magnitude, direction and stability of combining ability effects would serve in the development of competitive popcorn hybrids for a sustainable popcorn market. CONCLUSION Using the additive nature of popping quality traits and the dominant nature of GY, recurrent intrapopulation selection can be employed to derive desirable popping quality inbreds with high GY for genetic enhancement. Desirable popping quality alleles from novel germplasm can thus be combined with high‐yielding domestic elite inbreds to establish a sustainable popcorn breeding program. © 2024 Society of Chemical Industry.
... Popping quality is broadly categorised into expansion volume related traits and palatability traits, of which popping expansion volume (PEV), flake volume (FV) and popping rate (PR) are the critical determining factors (Sweley et al., 2013). While, high PEV substantially attracts sellers and buyers; unpopped kernels are unpleasant for palate. ...
... While, high PEV substantially attracts sellers and buyers; unpopped kernels are unpleasant for palate. A variety of factors such as kernel sphericity, moisture content, density and pericarp thickness are reported to have significant effects on popping volume (Sweley et al., 2013). Maximum expansion occurred in popcorn genotypes with the following kernel characteristics: >70% kernel sphericity, small to medium kernel size and minimal opaque endosperm core with 13.0-14.5% kernel moisture (Sweley et al., 2013). ...
... A variety of factors such as kernel sphericity, moisture content, density and pericarp thickness are reported to have significant effects on popping volume (Sweley et al., 2013). Maximum expansion occurred in popcorn genotypes with the following kernel characteristics: >70% kernel sphericity, small to medium kernel size and minimal opaque endosperm core with 13.0-14.5% kernel moisture (Sweley et al., 2013). Intrinsic biochemical variables like linoleic acid and a-zeins positively affected PEV and FV (Borras et al., 2006). ...
Article
Popcorn is a specialty maize famously savoured worldwide as snack, and genetic improvement of popping quality traits is important to meet the growing market demand. Though quantitative trait loci (QTLs) for popping quality traits were reported, low resolution and inconsistent effects limits their direct deployment in targeted trait improvement. Considering the importance of popping quality, consensus and stable meta-QTL regions can be entailed in designing new cultivars with enhanced popping quality traits through genomics- assisted approaches. In the present investigation, 120 popping quality determining QTLs from 10 different reports were assembled for meta-analysis to obtain precise and consistent QTL(s) followed by identification of underlying candidate genes for popping quality. The study identified eight meta-QTLs on chromosome 1, two on chromosome 6 and one on chromosome 7 with significantly reduced confidence interval and high weightage (0.03-0.64). Of these, MpQTL-1.1, MpQTL-1.3, MpQTL-1.5, MpQTL-1.8 and MpQTL-6.2 each possessed more than 4 QTLs from independent studies. Additionally, MpQTLs overlapped the chromosomal regions associated with agronomic and kernel composition traits. Functional ontology analysis of MpQTL-1.1 identified simple sequence repeat (SSR) marker umc2012 associated with transcription factor ‘NACTF53’ that contained a cis-acting CBF-domain. The marker also significantly differentiated normal maize and popcorn inbreds for popping quality traits. In addition, gene models Zm00001eb002590, Zm00001eb002620 and Zm00001eb002650 lying within 0.14 Mb from umc2012 were involved in starch and other carbohydrate metabolism. The validated marker umc2012 within MpQTL-1.1 can be used for marker-assisted introgression of popping quality traits. This is the first comprehensive report on meta-analysis and validation of markers for popping quality traits in maize.
... Such factors as nutritional and organoleptic appeal have been identified as determinants of popcorn (Zea mays L. var. everta) quality [2]. Kernel expansion volume plays a vital role in the economic value, consumers' preference, and acceptability of popcorn. ...
... The higher quantity of popped kernel recorded in kernels obtained from organic fertilizer plots could be connected to the amount of moisture content and the kernel size as explained by Singh et al. [56]. The range of moisture content in the kernel falls within the limit when optimum expansion volume could occur according to Sweley et al. [2,55]. ...
... This is because kernels of small and medium sizes show greater flake and expansion volume than the larger kernel sizes [29,30]. The percentage of unpopped kernel in the compost-fertilized plots was within the acceptable limit from oil-popped kernels as reported by Sona et al. [58] and Sweley et al. [2]. The number and size of kernel are related to improvement in soil fertility by the applied materials, which varied with different amendments, but the indices were superior to the kernel obtained from the unfertilized plots. ...
Article
Full-text available
The dietary value of popcorn, an important snack, depends on its proximate and nutritional constituents, while the economic worth is based on popability and expansion traits of the kernels. There is paucity of information on how soil fertility influences or relates with popping potentials as well as quality of popcorn kernel in semi-arid region. Therefore, the proximate composition and popping parameters of popcorn in response to organic and inorganic fertilizers were investigated. The field trial was conducted in 2017-2019, and it comprised five amendment rates including 90 and 180 kg ha-1 NPK fertilizer and 4 and 8 t ha-1 compost and unamended treatment as the control. The trial was arranged in randomized complete block design in triplicate. Data on kernel yield, biomass, and harvest index were evaluated. Kernels were analysed for proximate composition and popping indices using standard procedures. Across the two seasons, mean protein (8.1%) and fibre (10.2%) contents were highest in kernels from plots fertilized with NPK at 180 kg ha-1, while grains from plots fertilized with 8 t ha-1 compost had the highest moisture (19.3%) and starch (50.1%) contents. The highest kernel expansion of 54.18 cm3 g-1 and 77.6% popped kernels were obtained in plots fertilized with 4 t ha-1 compost. Most of the kernels (61%) were small-sized caryopsis. Popability is significantly associated with volume expansion ( r = 0.696 ). Proximate components and popability improved greatly in compost-augmented field relative to the unfertilized plots. Application of 4 or 8 t ha-1 sorted municipal solid waste compost to Luvisol enhanced growth and nutritional quality of popcorn. In view of promoting nutrient cycling towards improving soil fertility without compromising environmental health, compost is comparable and a good alternative to fossil-based mineral fertilizers.
... Genetic make up of a variety and deployed processing steps alter the nutritional content of rice (Mbanjo et al., 2020). However, new studies suggest that processing does not always degrade nutrients, even when heat is used (Kasote et al., 2021;Sweley, Rose, & Jackson, 2013). Consumers are becoming familiar with health benefits of functional foods and nutraceuticals. ...
... The food industry may want to expand popped kernel size to boost revenues as larger kernels may reduce mass production costs by minimizing breakage during handling and distribution while offering an aesthetically pleasant snack. Hence, bigger popped kernels are lucrative for producers and more satisfying for consumers (Sweley et al., 2013). This, however, must be substantiated in popped rice by consumer and industry surveys. ...
... The influence of bran composition in BD warrants further research. Unpopped grains affect appeal, thus manufacturers strive to minimize them (Sweley et al., 2013). This non or low popping is caused by low moisture. ...
Article
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Iron-pan roasting is a common processing technique used in India to produce value-added popped rice. For the first time, traditional landrace genotypes black rice (Chak-hao), red (CRVR 68), Kalanamak, and a high-yielding variety Samba Mahsuri (SM) were extensively examined for the effects of the popping process on their physical and biochemical properties. SM had the highest volume increase and popping percentage, both of which are consumer-preferred attributes for popped products. The Fe content was significantly increased by popping in all genotypes. The Mg content of de-husked Red and Chak-hao did not substantially differ from that of its popped forms. Total starch decreased in popped red and Chak-hao, owing to amylose/amylopectin leaching from the grains. Popped landrace accessions retained most bioactives (∼70%, oryzanol, 14–28% total phenolic content, 48–65% total flavonoid content, and 38% total anthocyanin content) and antioxidant potency, especially in pigmented rice. Interestingly, the popped rice retained total dietary fibre across all genotypes. This work demonstrated that pigmented rice landraces can be transformed into nutraceutically-rich and wholesome, ready-to-eat popped rice product that is consumed as a primary product or as an ingredient to novel functional foods that could optimize human health.
... Popcorn, has been a delightful snack for centuries and has gained considerable commercial importance today. By heating the corn and reaching the appropriate temperature, it expands with an explosive sound and its volume reaches up to 30 times the volume of the main corn (Sweley et al., 2013). The primary packaging system for the retail sale of popcorn has been flexible bags made of polyethylene. ...
... Results showed that with increasing storage time, popcorn taste decreased (Table 5). Taste is closely associated with aroma, and many compounds have been identified that contribute to popcorn aroma and flavor, including pyrazines, furans, pyrroles, carbonyls, and substituted phenols, with pyrazines playing a major role in imparting the characteristic popcorn flavor and aroma (Sweley et al., 2013).. Popcorn odor scores packed in the uncoated cup was higher than the ones in the coated cup (Table 5). Grosch & Schieberle (1997) showed that the taste of popcorn is not stable. ...
... Increasing the humidity and decreasing the volume reduced the brittleness of the product during the storage period and as a result reduced the general acceptance of the samples (Table 5). High-quality popcorn texture is defined as crispy and melts in the mouth, versus low quality being that which is chewy and adhesive to the teeth (Sweley et al., 2013). Plimpton (1984) showed that packaging materials had significant effects the popcorn shelf life stability, off flavor, rancidity development, and crispness deterioration. ...
Article
Full-text available
Abstract Biodegradable paper cups coated with rice bran wax and whey protein isolate were designed to package popcorn. Coatings with different concentrations of whey protein isolate (5.5, 7.75, and 10% w/v) and rice bran wax (0.2, 0.4, and 0.6% w/v) were applied on the outer surface of the paper cups. Thickness, color changes, Young's modulus and tensile strength, water vapor transmission rate (WVTR) of the coated and uncoated cups, and also popcorns properties (pH, texture, and sensory properties) were evaluated. Water vapor transmission rate, Young's modulus, thickness, total color change index, and tensile strength of coated cups with the optimal coating formulation was 19.785 (g/m2 day), 11.810 (MPa), 276.583 (µm), 1.839, and 11.222 (MPa), respectively. The results showed that paper cup coating increased thickness and yellowness and reduced the brightness, Young's modulus, and WVTR. Coating had a positive effect on the pH and texture of popcorns packaged in coated cups than samples packed in uncoated cups (p
... It is understandable that expansion volume became one of the first quality traits of popcorn to be studied due to its defining immediacy to 'popcorn' varieties, but other traits such as popability, hull dispersion, flake morphology, kernel size, color and morphology, and flake texture and flavor were explored throughout 1943-1993(Eldredge and Lyerly, 1943Grogan et al., 1958;Lin and Anantheswaran, 1988;Mohamed et al., 1993;Quinn et al., 2005;Sweley et al., 2013). These trait measurements will be described in turn beginning with popability and hull dispersion, traits closely linked to expansion volume in regard to methodology. ...
... This trait is best assessed after popping by evaluating the brown 'shell' left remaining on the popped flake. Relatively, the more connective hull marks a lower hull dispersion score (Zeigler, 2001;Sweley et al., 2013). Flake morphology has been identified as an interactor with hull dispersion; butterfly flakes tend to have more effective hull dispersion while mushroom morphologies tend to retain hulls after popping Watson, 1988;. ...
... Willier and Brunson's 1927 study also introduced a secondary means of counting kernels by weight and allotting kernels into these three main categories (Willier and Brunson, 1927). The current measure used 19 is a 10 gram sample composed of 52-67 'large ' kernels, 68-75 'medium' kernels, or 76-105 'small' kernels (Ziegler et al., 1984;Sweley et al., 2013). Both means of considering kernel size are found in literature, though counting kernels per 10 grams is perhaps more frequent in recent publications. ...
Article
In 2017, twelve Quality Protein Popcorn (QPP) inbred lines were developed and selected as premier dent by popcorn crosses fit for hybridization and testing. These QPP inbred lines were derived from specific Quality Protein dent Maize (QPM) by ConAgra Brands® popcorn line crosses to produce high lysine, vitreous popcorn lines capable of near-equal popping characteristics compared to the original popcorn parents. The QPP hybridization project commenced in the summer of 2018 utilizing these 12 inbred QPP lines and crossing them in a full diallel. Since then, the production of QPP hybrids has employed a diverse set of selection factors evaluating agronomic, popping quality, protein quality, and sensory traits. In 2021, six QPP hybrids were selected for continued evaluation based on agronomic, protein, and popping characteristics, and two QPP hybrids were ultimately selected based on the results from a sensory study. Advisor: David R. Holding
... [1] Popcorn formation is a complex phenomenon characterized by the expansion of the corn kernel by the action of the flash evaporation of the water due to the heat flux from the media to the kernel. [2,3] Common sources of energy applied to pop are oil and microwaves [4] while less commercial attention has been put to hot-air processes. [5] Also, Sweley et al. [2] reported the influence of the popping method on physical properties of produced popcorn, indicating that hot-air popping produced higher expansion volumes of popcorn as compared with microwave and oil popping methods and pointed out that temperature of the heating media is important towards popcorn's quality. ...
... [2,3] Common sources of energy applied to pop are oil and microwaves [4] while less commercial attention has been put to hot-air processes. [5] Also, Sweley et al. [2] reported the influence of the popping method on physical properties of produced popcorn, indicating that hot-air popping produced higher expansion volumes of popcorn as compared with microwave and oil popping methods and pointed out that temperature of the heating media is important towards popcorn's quality. Hot-air popping does not require of any additives such as oil or butter as compared to oil and microwave popping methods thus giving rise to products that may be directed to lowcalorie consumption diets. ...
... Hot-air popping does not require of any additives such as oil or butter as compared to oil and microwave popping methods thus giving rise to products that may be directed to lowcalorie consumption diets. [2] A relative disadvantage of the hot-air popping method could be the popularity that oil and microwave methods have mainly related to the flavor of oil and butter and easiness of their preparation (microwave method) and the availability of a wide variety of microwave ovens and pans worldwide. Another factor that affects popping performance is the moisture content of the kernel since during popping the moisture content vaporizes into steam (or water vapor) at pressures reaching 830 MPa according to Hoseney et al. [3] During popping, steam migrates throughout its microstructure and escapes firstly across the protein matrix and intercellular spaces to reach the micro fractures in the kernel [2,[6][7][8][9] and released during the stages of popping. ...
Article
Upon popping, corn kernels undergo substantial dehydration. Initial moisture content of the kernel, popping method and temperature determine the final quality, and physical characteristics of the flakes. In this work, corn kernels (Zea Mays var Everta) at different moisture contents were subjected to hot-air popping and quality, physical and morphometric parameters of the flakes were evaluated, and related with their microstructural features. The best moisture content for hot-air popping was 9.14%. Macro and microstructural examination and digital image analysis of the flakes showed that, at the macro level, the roughness of the different flakes, as given by their fractal dimension (FD), were similar among morphologies, whereas at the microscale, it was possible to differentiate between them. Additionally, at the macro-scale, for the different morphologies high correlations were found between areas and the linear dimensions (Feret or width)FD of evaluated flakes. Moreover, when using the FD of the microstructures as the exponent, high correlations were also observed, which confirms an analog multiscale behavior between the roughness of the flakes and their microstructures.
... The physical and morphological characteristics of the kernel that contribute to the popping capacity are numerous. They include a more crystalline arrangement of the endosperm, the polygonal arrangement of the starch, pericarp hardness, amylose/amylopectin ratio, a higher degree of fibrillar packing of the pericarp, porosity, moisture content, and the presence of protein bodies in the pericarp and endosperm, especially the α-zeins (Hoseney et al., 1983;Park et al., 2000;Gökmen, 2004;Babu et al., 2006;Borras et al., 2006;Lee et al., 2000;Ertaş et al., 2008;Sweley et al., 2013;Dong et al., 2015;Vázquez-Carrillo et al., 2019). ...
... Likewise, the physical and morphological characteristics of the kernel that affect the EV such as the more crystalline disposition of the endosperm, thickness, and a higher degree of fibrillar packing of the pericarp (Da Silva et al, 1993) are more frequently found in the flint endosperm (Hoseney et al., 1983;Park et al., 2000;Gökmen, 2004). In popcorn, the extreme flint corn, the granules of the starch are densely packed, surrounded by protein matrices (Hoseney et al., 1983), and has twice the thermal conductivity as the opaque starch (Da Silva et al., 1993), characteristics which permit to reach a pressure of 135psi inside the kernel allowing to gelatinize and to form flakes Trejo-Pastor, et al. (Hoseney et al., 1983;Mishra et al., 2014;Sweley et al., 2013;van der Sman and Bows, 2017). All this together could provide an explanation for the higher EV observed in the F2 population derived from crossing with flint endosperm. ...
Article
Full-text available
The most important commercial feature in popcorn (Zea mays L.) is the expansion of the starch contained in the endosperm; however, little has been studied about the underlying genetic basis of this quantitative trait, for which the development of segregating populations is required. The first step is the selection of the most appropriate contrasting parents for popping capacity to create these populations. The objectives of this study were, 1) to analyze the popping patterns of F2 populations derived from crosses between popcorn × nonpopcorn inbred lines to identify the most divergent cross for future molecular analysis in search of alleles-related to popping capacity, and 2) to estimate the number of genes responsible for popping expansion volume based on the tails of segregation. Seven biparental crosses of popcorn × non-popcorn were performed to obtain F2 populations, and those were phenotypedfor popping expansion volume. Phenotypes were analyzed by the H test, Lilliefors normality-test, Fisher’s coefficient of skewness, and kurtosis level. The number of genes estimation was made with X2 and (1/4)n tests. The popping patterns indicated that popcorn × flint corn was the most divergent cross, with the most symmetrical distribution, and therefore, the best suitable population to be used for molecular analysis. Results indicated the existence of three to five major genes related to popping expansion volume. Transgressive segregation was present in all populations, showing individuals whit a popping expansion volume higher or lower than the parental ones, suggesting that non-popcorn lines contain variation for alleles that promote popping. Keywords: Popcorn, popping expansion volume, popping patterns, transgressive segregation, Zea mays L.
... Among the zein subunits, alpha-zeins are associated with endosperm hardness and their content has a high correlation (.96) with EV (Borras et al., 2006). Taking into account that starch is the major polymer involved in popcorn expansion (Sweley et al., 2013), popcorn breeding should be focused in increasing the 19 kDa alpha-zein, total zeins and starch contents. ...
... North American and Argentine commercial hybrids have an average starch content of 64.0% and an amylose/amylopectin ratio of 27.5/72.5 (0.40) (Borras et al., 2006;Sweley et al., 2013), which is the average value observed in the temperate and tropical popcorn populations. The amylose/amylopectin ratio affects the quality and development of the endosperm (Li et al., 2018), as well as properties useful to the food industry, such as gelatinization and solubilization, which are relevant aspects during the development of starch-based products. ...
Article
Full-text available
Because measuring expansion volume (EV) is simple and inexpensive, popcorn breeders have developed high‐quality single crosses ignoring the contents of zeins, starch, lipids, and cellular wall components in selection. However, some methods of quantification of these quality‐related traits can be applied to popcorn breeding, increasing the selection efficacy for quality. The objectives of this study were to assess methods of zeins and starch quantification that can be used in popcorn breeding, characterize a temperate and a tropical populations for zeins and starch contents and identify candidate genes for these quality‐related traits. We genotyped and phenotyped 286 plants. For quantification of total zeins and zein subunits we choose the ‘lab‐on‐a‐chip’ microfluidic electrophoresis. For quantification of starch and amylose/amylopectin, we choose the Megazyme's Amylose/Amylopectin kit assay. The temperate population has superior EV (36.0%), a higher level of the 19 kDa zein subunit (32.0%), lower levels of the 21, 22 and 27 kDa subunits (−1543.0%, −40.0% and −47.0%, respectively) and no statistical difference for the 10 kDa zein content, relative to the tropical population. Although there are statistical differences between the two populations regarding starch, amylose, and amylose/amylopectin ratio, the differences are not significant (−2.0% to 8.0%). Thirteen candidate genes were identified for the 19 and 22 kDa zeins, two for amylose and one for starch, with emphasis on the genes coding for the 19 and 22 kDa alpha‐zeins, located on chromosome 4. The evaluated quantification methods can be used in popcorn breeding but for a limited number of samples, mainly because costs.
... Butterfly-shaped popcorn is characterized by having a multilateral expansion and is preferred for home consumption. While mushroomshaped popcorn is commercially preferred because it is less susceptible to breakage during packaging and transportation than the butterfly-shaped popcorn (Sweley et al., 2013). In popping, the volumetric expansion ranges between 6 and 8 times (Bhatupadya et al., 2008), while it ranges from 4 to 10 times in the puffing process (Saha & Roy, 2022). ...
... As previously mentioned, the intense heat treatments induce some macromolecular transformations that are responsible for varying the sensorial characteristics of popped or puffed products (Schlörmann et al., 2020;Sweley et al., 2013). These transformations substantially affect the color, taste, flavor, and mouthfeel of popped or puffed products (Mishra et al., 2014). ...
Chapter
Nowadays, expanded cereal grains are greatly gaining popularity because they are easy to digest, light, crispy, and the most interesting that these products are ready for eating. Popping and puffing are simple and low-cost processes used for producing crispy-expanded products with an open porous structure, such as popcorn, puffed rice, and popped/puffed wheat. These expanded products can be produced by many different techniques, like hot sand bed, hot oil, hot air, gun and microwave puffing, and instant controlled pressure drop. Recently, infrared puffing has been adopted to produce these products. The mechanism of these techniques is based on the exposure of grain to high temperature for a short time, resulting in a phase transition from an amorphous to a rubbery state that ensures creating a sufficient superheated steam pressure within the grain matrix. The release of this pressure afterward causes the grain structure to expand. This chapter provides a review of different popping and puffing methods for cereal grains and covers the various quality attributes of popped and puffed cereal snacks as well as the factors affecting this quality.
... The physical and morphological characteristics of the kernel that contribute to the popping capacity are numerous. They include a more crystalline arrangement of the endosperm, the polygonal arrangement of the starch, pericarp hardness, amylose/amylopectin ratio, a higher degree of fibrillar packing of the pericarp, porosity, moisture content, and the presence of protein bodies in the pericarp and endosperm, especially the α-zeins (Hoseney et al., 1983;Park et al., 2000;Gökmen, 2004;Babu et al., 2006;Borras et al., 2006;Lee et al., 2000;Ertaş et al., 2008;Sweley et al., 2013;Dong et al., 2015;Vázquez-Carrillo et al., 2019). ...
... Likewise, the physical and morphological characteristics of the kernel that affect the EV such as the more crystalline disposition of the endosperm, thickness, and a higher degree of fibrillar packing of the pericarp (Da Silva et al, 1993) are more frequently found in the flint endosperm (Hoseney et al., 1983;Park et al., 2000;Gökmen, 2004). In popcorn, the extreme flint corn, the granules of the starch are densely packed, surrounded by protein matrices (Hoseney et al., 1983), and has twice the thermal conductivity as the opaque starch (Da Silva et al., 1993), characteristics which permit to reach a pressure of 135psi inside the kernel allowing to gelatinize and to form flakes Trejo-Pastor, et al. (Hoseney et al., 1983;Mishra et al., 2014;Sweley et al., 2013;van der Sman and Bows, 2017). All this together could provide an explanation for the higher EV observed in the F2 population derived from crossing with flint endosperm. ...
Article
Full-text available
The most important commercial feature in popcorn (Zea mays L.) is the expansion of the starch contained in the endosperm; however, little has been studied about the underlying genetic basis of this quantitative trait, for which the development of segregating populations is required. The first step is the selection of the most appropriate contrasting parents for popping capacity to create these populations. The objectives of this study were, 1) to analyze the popping patterns of F2 populations derived from crosses between popcorn × nonpopcorn inbred lines to identify the most divergent cross for future molecular analysis in search of alleles-related to popping capacity, and 2) to estimate the number of genes responsible for popping expansion volume based on the tails of segregation. Seven biparental crosses of popcorn × non-popcorn were performed to obtain F2 populations, and those were phenotypedfor popping expansion volume. Phenotypes were analyzed by the H test, Lilliefors normality-test, Fisher’s coefficient of skewness, and kurtosis level. The number of genes estimation was made with X2 and (1/4)n tests. The popping patterns indicated that popcorn × flint corn was the most divergent cross, with the most symmetrical distribution, and therefore, the best suitable population to be used for molecular analysis. Results indicated the existence of three to five major genes related to popping expansion volume. Transgressive segregation was present in all populations, showing individuals whit a popping expansion volume higher or lower than the parental ones, suggesting that non-popcorn lines contain variation for alleles that promote popping.
... Popcorn, a whole grain snack, provides greater satiety than potato chips and is rich in nutrients [6]. Popcorn (Zea Mays Everta) differs from regular corn by its ability to expand to many times their original size [17]. The endosperms of popcorn kernels are surrounded by a layer of extremely hard shell called the pericarp [18]. ...
... When the kernels are subjected to heat, moisture within the endosperm or starch layer turn to gas. Due to the hard pericarp, the gas is trapped inside; allowing popcorns to expand [19] Popcorns are rich in fibre the fibre [17] in popcorn is found in the pericarp, with the major fibre being hemicelluloses. Australian Food, Supplement and Nutrient Database (AUSNUT) [20] reported popcorn as having between 5.2 to 16.5 g of dietary fibre per 100 g of popcorn, depending on the method of preparation. ...
Article
The possible improvement of the health benefits of popcorn via coating with chocolate was investigated. Free and bound polyphenols were extracted from plain popcorn (PP), chocolate (Ch) and chocolate-coated popcorn (CCP), and analysed separately. The total polyphenol content (TPC) was measured using Folin-Ciocalteu assay, and trolox equivalent antioxidant capacity (TEAC) was analysed using DPPH and ABTS methods. The extracted phenolic compounds were analysed using a HPLC technique. Ch showed significantly (P<0.05) the highest TPC of 1560.49 ± 21.84 mg gallic acid equivalent (GAE)/100 g dry weight (DW). Additionally, Ch revealed the largest TEAC of 2559.50 ± 69.1 and 2378.50 ± 108.0 mg Trolox equivalent (TE)/100g DW, measured by DPPH and ABTS, respectively. CCP had significantly (P<0.05) smaller quantities of TPC and TEAC compared with Ch. PP had greater amounts of bound polyphenol (BPP) while both Ch and CCP had significantly (P<0.05) more free polyphenols (FPP). The HPLC analysis indentified nine different phenolic compounds in CCP including gallic acid (131.88 ± 3.70 mg/g DW), vanillic acid (30.04 ± 1.20 µg/g DW), caffeic acid (34.37 ± 1.33 µg/g DW), trans-ferulic acid (4.80 ± 0.30 µg/g DW), p-coumaric acid (13.37 ± 0.24 µg/g DW), sinapic acid (9.51 ± 0.50 µg/g DW), (±)-catechin hydrate (500.17 ± 10.36 µg/g DW), (-)-epicatechin (356.38 ± 5.47 µg/g DW) and quercetin hydrate (75.39 ± 3.93 µg/g DW).
... Maize or corn (Zea mays E.) is the second largest crop produced in the world and is the staple food in various countries (Sweley et al., 2013). An important product derived of this maize is popped corn (popcorn or flakes) and is one of the most popular snacks consumed worldwide (Farahnaky et al., 2013). ...
... In the same publication, these authors classified the different morphologies for microwave popcorn in four types: mushroom, unilateral, bilateral and multilateral depending on the amount of the main appendages formed. Also, some morphometric parameters have been studied for oil or microwave popcorn by using callipers (Sweley et al., 2012a(Sweley et al., , 2013Karababa, 2006;Mohamed et al., 1993;Pordesimo et al., 1990). However, there are not reports on geometric characteristics of the flakes during hot-air popping. ...
Article
Four popcorn morphologies have been described but an account of the sizes and shapes that each morphology had during hot-air popping have not been reported. In this work, high-speed videos of popping kernels were captured to study two-dimension (2-D)morphometry changes during hot-air popping. Six main observed geometries during popping were: initial kernel, kernel with incipient expanded pericarp, kernel at the onset of the popping, splitting of the endocarp, formation of appendages and, the developed flake, in such a way as to allow the definition of 5 stages during popping (one stage between each one of the above geometries). Total duration for the formation of each morphology was 0.480, 0.344, 0.140 and 0.343 s for mushroom, unilateral, bilateral and multilateral flakes respectively. Projected area and perimeter increased due to the expansion of the kernel, circularity decreased since the flakes showed a decrease in roundness and smoothness and, on the other hand, the solidity, also decreased due to the decrement of smooth lines in the outside boundary of the flake. It is noteworthy that the two parameters (circularity and solidity)dropped following the same sequence during popping and that the main difference among geometries was the time taken to pop.
... Popping quality has been defined by at least three essential variables: expansion volume, the number of unpopped kernels, and the popped kernel size. These quality traits depend on the genotype, kernel physical and chemical properties, popping conditions, as well as the harvesting and handling practices (Sweley et al., 2013). Expansion volume is crucial in the popcorn market because popcorn is sold by volume rather than weight. ...
... There was a positive correlation between α-zeins and vitreous endosperm (r = 0.49, P ≤ 0.05) (Supplementary material 1). The α-zein proteins have been reported to be positively correlated with the popping expansion volume because they play an important role in defining the endosperm texture (Borras et al., 2006;Sweley et al., 2013). Consistent with these results, micrographs of kernels containing higher vitreous endosperm (commercial popcorn and 612) showed a denser protein matrix surrounding the starch granules ( Fig. 1a and e) compared with poor protein matrix observed in the endosperm of the softer accession 608 (Fig. 1c). ...
Article
Chapalote is a Mexican ancient maize landrace with popping characteristics that have not been studied. This work aimed to study the kernel physicochemical properties and their relationship with popping properties of 10 Chapalote accessions. Two popping methods, cooking pan and hot-air popping, were tested. A commercial popcorn sample was used for comparison purposes. Hot-air popping led to higher expansion volume, less unpopped kernels, and bigger popped kernels than traditional popping. Among Chapalote samples, one accession (612) had the best popping properties, but none of them popped similarly to the commercial popcorn. This behavior may be related to the non-breeding origin of Chapalote accessions contrasting with the improved hybrids. Smaller kernels containing more pedicel, pericarp, and vitreous endosperm led to higher expansion volume and lower unpopped kernels. In air-popping, higher α-zein content, and bigger starch granules with less crystallinity influenced positively the popping properties, mainly the air bubbles and popped kernel size. Pericarp thickness was not a crucial factor in popping performance. Some Chapalote accessions with good popping quality could be an important source of germplasm in breeding programs for the development of modern popcorn varieties with distinct properties, which may help to avoid the extinction of this landrace.
... (Crumbaker et al., 1949). Instead of gelatinization during the popping process in the translucent endosperms of popcorn, the starch granules in opaque endosperms do not get penetrated by water vapor (Sweley et al., 2013). ...
... Malnutrition has been a major health problem across developing countries (Müller and Krawinkel, 2005). Popcorn enjoyed nearly a constant increase in sales during the second half of the twentieth century (Sweley et al., 2013). This was due to significant advancements in popcorn quality traits such as maximizing popping expansion volume (PEV) and percentage popped kernels as well as flake type and quality as well as the development of microwave popcorn. ...
Article
I have been working on a Quality Protein Popcorn breeding project where QPM conversion is carried out simultaneously for several elite popcorn germplasms. During my study in the graduate program, I led the following aspects of the Quality Protein Popcorn Breeding Project: 1. Identified suitable QPMs as opaque-2 allele donors. 2.Examined the feasibility of quick introgression of the opaque-2 allele into popcorn lines via marker-assisted selection. 3. Monitored modification by SDS-PAGE zein profiling and light box phenotypic selection to make sure multiple modifier loci for opaque-2 were incorporated each time generation advancement was carried out. 4. Carried out high throughput DNA extraction using the BioSprint Workstation and performed genotyping to guide field selection. 5. Principle Component Analysis (PCA) of amino acid profiles from UPLC (Ultra Performance Liquid Chromatography) of candidate QPP lines along with corresponding parental lines (QPM and popcorn). (in collaboration with Dr. Ruthie Angelovici from University of Missouri Columbia, MO) Advisor: David R. Holding
... Ref. [25] considered that the phenotypic traits of flake characteristics such as taste, texture, color and shape can be determinants of popcorn quality. Quality includes physical attributes such as shape, density, size, hardness and grain pericarp thickness, as well as compositional attributes, such as the levels of zein protein and types of fatty acids in grain [26]. All these traits are influenced by environmental conditions. ...
Article
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The current popcorn production in Mexico is insufficient to meet the demand for this grain, since there are no genotypes suitable for production within the country. The native popcorn varieties do not meet market standards; therefore, it is necessary to carry out genetic improvement on yield and popping expansion. The objective of this study was to estimate the response to selection on yield and popping expansion of popcorn under two modalities of mass selection. We used a population of popcorn from the first selection cycle (C1) of the cross between a commercial popcorn of the North American Yellow Pearl race and a native population of the Mexican race Palomero Toluqueño. An additional cycle of mass selection (C2) was carried out with stratification (MSS) and without stratification (MNSS) followed by a field trial that included the different cycles of selection. The parents of the initial cross and two controls, under a complete randomized block experimental design with 10 replications in two localities, and the genetic gain per cycle was calculated. Genotypes C2MSS, C2MNSS, C1MSS and the control Palomero Ixtenco showed the highest average grain yield with values of 4.9 t ha−1. For popping expansion, the Jack Superior control showed the best flake volume with 34.7 cm3 g−1, in contrast to the native popcorn Criollo Plaza with a value as low as 7.2 cm3 g−1. Chapingo was the locality with the highest grain yield, averaging 5.08 t ha−1, while in San Salvador Atenco, the yield was 2.78 t ha−1. Genetic gains were found with a popping expansion of 12.50% with stratification and 11.42% without stratification. For grain yield, a gain of 6.82% was obtained using stratification and 0.74% without stratification. Stratified visual mass selection is an efficient method for genetic advancement in popcorn yield, while popping mass selection is efficient regardless of stratification.
... A whole pericarp is the main requirement for proper kernel expansion [55]. Grains with a fragile pericarp may release some internal pressure before popping, resulting in lower expansion volumes. ...
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Ozone gas (O3) is a promising alternative for fungal inactivation in agricultural commodities. This study aimed to (i) investigate the influence of airflow on the saturation of popcorn kernels with ozone gas, (ii) evaluate its effectiveness in controlling Aspergillus flavus, and (iii) analyze the quality of ozonated grains. Samples of 3.0 kg of kernels were exposed to oxygen (control) or ozone at specific flow rates of 0.15 or 1.00 m3 min−1 t−1, with an input ozone concentration of 16.0 mg L−1 for 0, 6, 12, 24, 36, or 48 h. Quality parameters assessed included expansion volume, water content, electrical conductivity, and color. At 0.15 m3 min−1 t−1, ozone consumption and saturation time were lower, with an 80% reduction in A. flavus infection after 6 h. This flow rate did not affect grain expansion or water content. Conversely, at 1.0 m3 min−1 t−1, reductions in water content and expansion were observed with extended exposure. Electrical conductivity increased in both treatments, more significantly at the lower flow rate. In conclusion, ozonation at 0.15 m3 min−1 t−1 effectively inactivated A. flavus without compromising grain quality
... Popcorn, widely recognized for its high fiber content and popularity as a healthy snack [17], undergoes significant mechanical changes when exposed to heat. These changes alter the kernel's size, shape, and diameter, including the expansion and bursting of its thicker endosperm [18,19]. These characteristics of popcorn make it a suitable candidate for generating by-products like nejayote during nixtamalization, which can be utilized in film production. ...
Article
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This study investigated corn pericarp, a by-product of the nixtamalization process, in developing sustainable films for fruit coatings. These films were evaluated for their optical, structural, barrier, and mechanical properties. The results showed that the pericarp films were transparent, had heterogeneous surfaces, and exhibited favorable mechanical and barrier properties, suggesting their potential as fruit coatings. The pericarp films significantly extended shelf life when applied to peaches and tejocotes postharvest. The films slowed the maturation process, as evidenced by minimal changes in peel and mesocarp color for up to five days for tejocotes and even longer for peaches. Additionally, coated fruits showed slower rates of weight loss, firmness reduction, and decreases in titratable acidity, total soluble solids, and total sugar content compared to control samples. These findings demonstrate the potential of corn pericarp films as effective coatings for extending the shelf life of stone fruits.
... The negative correlation between GY and PE, following reports from other studies (Dofing et al., 1991;Li et al., 2008;Sweley et al., 2013), once again proved to be a problem for obtaining simultaneous gains for these two traits via direct univariate selection. Similarly, selection using the PV super trait proved effective in achieving simultaneous gains at lower selection pressures (40% and 30%). ...
Article
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Fusarium ear rot (FER) is a disease that causes a decrease in grain quality in several popcorn fields in tropical regions. To contribute to the development of popcorn cultivars resistant to FER and superior in the main agronomic traits, the study aimed to compare gains in popping expansion (PE), grain yield (GY), and FER resistance through direct and indirect selection strategies by proposing a new super trait. The study was conducted in Campos dos Goytacazes, RJ. The traits were evaluated in 41 inbred lines from four environments using a randomized block design with four replicates. Six selection strategies and four selection intensities were tested. Direct selection on GY resulted in losses in PE and small gains in FER in the majority of the environments. Positive selection on PE resulted in FER reduction in scenarios of lower selection intensity. Selection by popping volume showed a satisfactory increase in GY and PE but was not effective in FER reduction. Selection by multi‐trait genotype–ideotype distance index resulted in GY increase only in some environments, PE increase in all environments, and FER reduction in all environments under higher selection intensities. The newly developed super trait popping volume without Fusarium (PVwF) showed the possibility of increasing GY (32.90% at 88.8%) and PE (5.10% at 10.20%) while simultaneously reducing FER in all environments and selection intensities (−6.30% at −6.70%). PVwF is an easily executable methodology to help popcorn breeders optimize gains in their programs. The lines L214, L217, L292, and L328 are more suitable for use in mating blocks aimed to develop superior popcorn hybrids.
... Over millennia of artificial selection, maize has been known for its extreme genetic diversity at the population level (Hufford et al., 2021), leading to substantial variations in kernel characteristics among different maize inbred lines (Zhou et al., 2019). In contrast, popcorn typically has comparatively smaller kernels than other types of corn and is inferior to dent corn in yield and other agronomic traits (Sweley et al., 2013). The underlying molecular genetic mechanism responsible for the persistence of small kernels in popcorn remains unknown. ...
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Kernel weight is a critical factor that essentially affects maize (Zea mays) yield. In natural inbred lines, popcorn kernels exhibit overtly smaller sizes compared to dent corn kernels, and kernel weight, which is controlled by multiple genetic loci, varies widely. Here, we characterized a major quantitative trait locus on chromosome 1, responsible for controlling kernel weight (qKW1) and size. The qKW1 locus encodes a protein containing a seven in absentia domain with E3 ubiquitin ligase activity, expressed prominently from the top to the middle region of the endosperm. The presence and function of qKW1 were confirmed through ZmKW1 gene editing, where the mutations in ZmKW1 within dent corn significantly increased kernel weight, consistent with alterations in kernel size, while overexpression of ZmKW1 had the opposite effect. ZmKW1 acts as a negative regulator of kernel weight and size by reducing both the number and size of the endosperm cells and impacting endosperm filling. Notably, the popcorn allele qKW1N and the dent corn allele qKW1D encode identical proteins; however, the differences in promoter activity arise due to the insertion of an Indel‐1346 sequence in the qKW1N promoter, resulting in higher expression levels compared to qKW1D, thus contributing to the variation in kernel weight and size between popcorn and dent corn kernels. Linkage disequilibrium analysis of the 2.8 kb promoter region of ZmKW1 in a dataset comprising 111 maize association panels identified two distinct haplotypes. Our results provide insight into the mechanisms underlying kernel development and yield regulation in dent corn and popcorn, with a specific focus on the role of the ubiquitination system.
... This may be because they are made with popcorn and not roasted corn. According to Sweley, Rose & Jackson (2013), in popped corn, there is evidence of incomplete starch gelatinization because a large part of the starch granules remains intact. Based on that knowledge, popped grains of Cristalino maize could be less prone to retrogradation because a portion of their endosperm does not gelatinize nor change its structure which could explain the absence of a dry texture in the samples. ...
Article
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El pinole es una harina fina hecha con base en maíz reventado, tostado y es el alimento predominante en la dieta Rarámuri. Este trabajo tiene como objetivo avanzar en el mapeo sensorial del pinole de la Sierra Tarahumara de Chihuahua, México y evaluar su aroma. Se analizaron tres muestras del producto utilizando el Perfil Flash modificado, la cromatografía de gases-la espectrometría de masas con extracción dinámica en la fase sólida de espacio de cabeza (HS-SPDE) y la nariz electrónica (e-nose). En el análisis de la nariz electrónica hubo pocas diferencias significativas entre los pinoles. En los resultados del perfil sensorial las características descriptivas (diecisiete atributos en total)discriminaron cada muestra, como una consecuencia de las ligeras diferencias en los procesos tradicionales aplicados. Se identificaron cuarenta y nueve compuestos volátiles en las tres muestras, de los que veintidós se habían determinado previamente en las palomitas de maíz y en otros productos de maíz. El Análisis Factorial Múltiple mostró correlaciones de varios compuestos volátiles (p. ej., los compuestos heterocíclicos formados durante el tostado y el ahumado) y las respuestas de los sensores con dos tipos de atributos: de olores sensoriales como maní, maíz, tostado, dulce y pinole, y los de sabor como tostado, pinole, dulce y maíz.
... PEV is defined as the ratio of volume of popped kernels (cm 3 ) to weight of unpopped kernels (g). Hence, the research focus has been shifted towards improving popping quality traits rather than inferior agronomic traits through germplasm diversity (Metzger et al. 1989;Sweley et al. 2013). Additionally, high PEV with desirable flake texture including fluffiness, tenderness, and aroma are the preferable attributes at consumer's end. ...
Chapter
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Specialty corn has emerged as a preferred choice as food, feed, and various industrial products due to its diverse usage. Among the various types, sweet corn, popcorn, waxy corn, high amylose corn, high oil corn, colored corn, and baby corn are quite popular worldwide. Genes or QTLs governing these traits are now well documented. Introgression of such loci has led to the development of improved specialty corn cultivars worldwide. Information on markers has further helped in accelerating the breeding cycle through marker-assisted breeding. Crop biofortification has now regarded as a sustainable and cost-effective approach to alleviate malnutrition. Various genes are now available to enhance nutritional quality like provitamin-A, provitamin-E, lysine, and tryptophan in maize. These nutritional quality traits have been integrated into the genetic background of specialty corn cultivars. Here, we present the importance of each of the specialty corn, their genetics, and scope of enhancing the nutritional quality traits in the specialty corn background. Various challenges in popularization and adoption of the biofortified maize have also been discussed.
... PEV is defined as the ratio of volume of popped kernels (cm 3 ) to weight of unpopped kernels (g). Hence, the research focus has been shifted towards improving popping quality traits rather than inferior agronomic traits through germplasm diversity (Metzger et al. 1989;Sweley et al. 2013). Additionally, high PEV with desirable flake texture including fluffiness, tenderness, and aroma are the preferable attributes at consumer's end. ...
Chapter
Maize being versatile crop is known for its many uses. It has substantially contribution to food security in the poor country. In the recent past, deliberate attempts have been made to integrate trait-based genomic approaches to complement conventional plant breeding. However, the success of the genomics mainly based on phenotypic expression of a trait, hence phenotyping, is one of the key components of plant breeding including maize. Genetic dissection of key traits and its molecular mechanism involves extensive phenotyping of large set of population. Screening of such a huge population is with traditional methods, which is expensive and tedious and consumes a lot of time. In addition, plant phenotypes are the results of interaction between genotype × environment × management (G × E × M); thus, they are complex in nature. Recent developments in phenomics led to the improvement in phenotyping protocol that is more powerful than ever to dissect complex traits into easily scorable traits. In addition, this helps in uncovering underlying genetic mechanism for trait expression. This chapter aimed at describing phenotyping tools available for plant scientist to fast track their maize improvement in precise and robust manner for climate resilient agriculture.
... During expansion under intense heat treatment, some chemical transformations of compounds in the grains are grossly responsible for altering sensory qualities (Buttery et al., 1997;Schlörmann et al., 2020;Sweley et al., 2013). The degree of such alteration depends on the processing conditions. ...
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Ready to eat expanded food grains are gaining popularity in modern days due to their ease to digest, lightness, crispiness, and most importantly are ready to eat in nature. The demand for these products is increasing gradually, which tempts researchers to develop products with enhanced quality more diversifications in product and taste. An integrated study on food grain expansion helps to understand these processes. Puffing and popping process expands the grain by many folds. Expansion of grains depends upon heat and mass transfer rate, which take place in the counter direction. Therefore, optimal heat and mass transfer conditions affect final quality and play an important role. Processing methods and grain characteristics influence these processes. Processing parameter levels and grain characteristics are interrelated. Optimum levels of processing parameters differ with changes in processing methods. This review article explains the effect of processing parameters on product quality and influencing mechanisms.
... The heat transfer coefficient in the popcorn kernel is approximately 1.9 times higher than in the common corn kernel, providing a more efficient heat transfer into the grain, so that the internal temperature increases quickly (Silva et al., 1993). Sweley et al. (2013) suggested that the cell wall matrix of popcorn is more orderly than that of common corn. The grain expands when subjected to temperatures around 180 • C for a short period (Hoseney et al., 1983;Silva et al., 1993;Mishra et al., 2014). ...
Article
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The popping expansion is a characteristic that is positively related with the quality of popcorn. A positive correlation between the volume of expansion and the thickness of the pericarp, and between the proportion of the opaque/shiny endosperm and the grain weight and volume, were postulated. However, there are no reports in the literature that address the importance of cell wall components in the popping expansion. Here, we investigate the biochemical composition of the pericarp cell walls of three inbred lines of popcorn with different popping expansion. Inbred lines GP12 (expansion volume >40 mL g⁻¹), P11 (expansion volume 30 mL g⁻¹) and P16 (expansion volume 14 mL g⁻¹) were used for the analysis and quantification of monosaccharides by HPAEC-PAD, and ferulic and p-coumaric acids and lignin by HPLC. Our hypothesis is that the biochemical composition of the pericarp cell walls may be related to greater or lesser popping expansion. Our data suggest that the lignin content and composition contribute to popping expansion. The highest concentration of lignin (129.74 μg mg⁻¹; 12.97%) was detected in the pericarp cell wall of the GP12 inbred line with extremely high popping expansion, and the lowest concentration (113.52 μg mg⁻¹; 11.35%) was observed in the P16 inbred line with low popping expansion. These findings may contribute to indicating the quantitative trait locus for breeding programs and to developing other methods to improve the popping expansion of popcorn.
... Popcorn sensory traits such as texture and taste have been associated with multiple popcorn characteristics, such as flake morphology, kernel morphology, pericarp color, and increasing genetic diversity of the popcorn cultivar (Sweley, Rose, & Jackson, 2011;Sweley, Rose, & Jackson, 2013;Paraginski et al., 2016;unpublished observations). However, as previously mentioned, the diversification and expansion of marketable popcorn products has relied more on external additions rather than improving popcorn germplasm. ...
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Quality Protein Popcorn (QPP) varieties were bred out of a unique germplasm pool derived from Quality Protein dent Maize and conventional popcorn lines. To identify and compare distinctive characteristics within this population, a new sensory method was employed that coupled hedonic numeric rankings of common sensory traits appearance, aroma, texture, and taste with an “overall likability” score while requiring the selection of specific descriptors for taste and texture. Participants tasted six popcorn cultivars, rated each sample based on sensory factors, and offered specific descriptors for taste and texture. This sensory method identified two QPP hybrids with higher overall likability rankings likely attributed to the diversified and improved taste and texture of QPP compared to the controls. The experimental design employed for this descriptive analysis was successful in identifying trait correlations, potential consumer preferences, and ranking of product acceptability and may serve as an efficient model for other sensory studies. Practical Application Quality Protein Popcorn cultivars are novel products due to their unique genetic composition of elite popcorn and Quality Protein Maize dent maize. To evaluate consumer acceptability of these novel products, a new method for the sensory evaluation of common traits—appearance, aroma, texture, taste, and overall likability—was generated to identify desirable popcorn hybrids and correlations between overall likability and certain sensory attributes. Utilizing a numerical ranking system and categorical key descriptors, this study identified desirable popcorn characteristics and suggested explanations for these attributes. The evaluation format and experimental design employed enabled the identification of significant differences, trends, and correlations between traits and overall likability in a tested population of 112. These methods are easily transferable and may serve as an efficient model for other sensory studies identifying trait correlations, consumer preferences, and ranking of product acceptability.
... The pericarp is the layer of containment and protection of the endosperm. During heating, it has the function of confining the interior pressure of the kernels, and is fundamental in ensuring an adequate popping volume of the popcorn kernels (Sweley et al., 2013). The importance of this layer was pointed out by Silva et al. (1993), who described a 90.4% reduction in PE of popcorn kernels after removal of the pericarp. ...
Article
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Knowledge about relationships between traits can contribute to raising the efficiency of selection of superior genotypes. The objective of this study was to estimate the correlations, direct and indirect effects of agronomic, chemical and physical traits of kernels on popping expansion (PE) in popcorn (Zea mays L.). The trial was carried out in the 2017/2018 growing season, in Maringá ‐ PR, with 49 treatments, which consisted of 43 popcorn, four flint, and two sweet corn. The trial was arranged in a randomized complete block design with three replications. Multiple agronomic, chemical, physical, and popcorn quality traits were evaluated. Analysis of variance was performed to estimate the coefficients of phenotypic and genotypic correlations and the direct and indirect effects of path analysis. The genotypes were partitioned into genotype within each kernel type (popcorn, flint, and sweet corn) and two more contrasts (popcorn vs. [flint + sweet corn]) and flint vs. sweet corn. Positive phenotypic (.76) and genotypic correlations (.81) between popping expansion and pericarp thickness were detected. Kernel length had negative phenotypic (−.75) and genotypic correlations (−.78) with PE. Path analysis indicated that pericarp thickness has a direct and positive effect on PE and that the observed positive correlation with thermal diffusivity of the kernel pericarp and kernel length can be explained by indirect effects of the pericarp thickness. Evaluating kernel length may be most prudent considering economical and practical constraints to popcorn breeding programs.
... L. H. Bailey], a popular snack food with tasty and nutritious properties, is a type of specialty maize (Paraginski et al. 2016). Popping expansion trait, the most important quality trait of popcorn, easily distinguishes popcorn from other types of maize (Sweley et al. 2013). Other types of maize, such as flint and dent maize, can also produce small flakes after heating, but with much lower popping expansion ability than popcorn, and it is difficult to use them in modern snack production (Hallauer 2000). ...
Article
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Popcorn is a kind of snack food and has a breeding history of nearly 40 years in China, however, there are relatively few studies on its genetic diversity. Therefore, we present a genetic diversity and population structure analysis of 103 popcorn accessions, including 10 landraces from Latin America, 8 landraces from Southwest China and 76 and 9 popcorn breeding lines from China and the US, respectively, using polymorphic single-nucleotide polymorphisms (SNPs) developed by genotyping-by-sequencing. A total of 40,120 high-quality SNPs (19.21 SNPs per 1 Mb) were identified across the genome. Relative kinship analysis showed that the kinship coefficients for 0.3% of the pairs of lines were above 0.300, which agrees with the pedigree. The 103 accessions could be classified into three major groups based on model-based population structure, Neighbor-joining clustering, and principal component analysis based on the genetic background of the parents used for breeding. Group I consisted of landraces from both China and the Latin American countries, with some improved lines from landraces, while Group II and Group III consisted of lines primarily developed from popcorn commercial varieties, but with different levels of popping expansion ability. The average linkage disequilibrium decay distance in the entire panel under r² < 0.1 was 0.28 Mb and varied among different groups, indicating a narrow genetic resource. The information provided in this study will be helpful for breeders to incorporate identified genetic variation into hybrid breeding programs.
... a: X-ray diffraction pattern of raw sorghums; b: X-ray diffraction pattern of popped sorghums; c: viscosity profile of raw sorghums; d: viscosity profile of popped sorghums. Rose, & Jackson, 2013). ...
Article
The popping process has been widely used as a technique for obtaining snacks. This study evaluated the effect of the popping process on the structural and thermal properties of sorghum. Seven varieties of sorghum were used. Raw sorghum grains were adjusted to 11% moisture and popped at 210°C for 90 s with hot air. Microstructure, thermal and viscosity properties, and X-Ray and infrared spectrum were measured in raw and popped sorghum. The popping process produced an ordered honeycomb-like structure in the sorghum. The viscosity profile showed an increase in the thermal stability of popped sorghum. DSC measurements showed a starch gelatinization and a second transition about to 145°C. XRD diffractograms display a reduction in the amplitude of the crystalline orthorhombic structure peaks. Finally, infrared indicated a change in the short-range structure and protein denaturation due to the popping process.
... Popcorn is a widely preferred snack of maize worldwide. Popping characteristics of maize were originally selected by American Indians in early western civilizations (Carter et al. 1989;Sweley et al. 2013). However, the popcorn cultivars have lower yields as compared to the dent and flint corn hybrids and hence the improvement of popcorn cultivars has been undertaken by many researchers by using conventional breeding programs (Jele et al. 2014;Li et al. 2007a;Lu et al. 2003). ...
Article
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Popcorn (Zea mays L.) is a special type of maize that pops up when heated leading to high flake volume. It is being used as a popular fiber-rich and nutritious snack all over the world. The genetic control of the popping rate and flake volume is not well understood. The cross made between high popping volume inbred line as the female parent and low popping volume composite as the male parent. The F2 population of 504 plants showed continuous variation for popping volume signifying that the popping volume is a quantitative trait governed by multiple genes. Only a set of 126 out of 313 maize SSR markers were successfully amplified using the standard PCR reaction and 66 among these were found polymorphic between the two parents. Bulk segregant analysis (BSA) of F2 plants based on F2:3 seeds were carried out for mapping popping volume QTL using the 66 polymorphic SSR markers. Only four markers showed an association with popping volume in BSA. Out of the four, three SSR markers (bnlg1331, bnlg1520, bnlg1144) showed high association with the popping volume data after de-bulking of the positive and negative plants used in the bulks. All the 504 F2 plants were genotyped using 3 SSR markers and the F2:3 seeds were phenotyped for popping volume. The single marker analysis of the F2 plants showed that the 3 SSR markers bnlg1331, bnlg1520, and bnlg1836 on chromosome 1, 2, and 5, respectively, were closely associated with the QTL for popping volume covering 78% of total phenotypic variance.
... Popcorn (Zea mays Everta) is another popular snack product being considered healthier than chips due to its higher fiber and antioxidant content [10]. Upon heating to sufficient temperature, the caryopsis expands resulting in a large expansion of volume, producing the desired product [11]. Crackers are also popular snacks with low contents of moisture, sugar and fat that exhibit a thin and crispy texture. ...
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In this study, a method for the determination of trace elements in snacks using inductively coupled plasma–atomic emission spectrometry (ICP-AES) is presented. The examined elements were Pb, Ni, Cr, Cu, Mg, Zn, Fe, Al, Ba, Ca, Co, Mn and Cd. Under the optimized conditions, digestion of 300 mg of the snack samples was performed by the addition of 5 mL of nitric acid in a Teflon autoclave and by heating the obtained mixture at 120 °C for 75 min. In order to evaluate the efficiency of the proposed protocol, method linearity, accuracy precision, limits of detection (LODs) and limits of quantification (LOQs) were evaluated. The relative standard deviations (RSD%) for all elements were lower than 13.5%, demonstrating that the method offered good precision. The relative recoveries values (R%) ranged between 80–120%, demonstrating that the method offered good accuracy. The LODs for all the trace elements ranged between 0.18 and 3.75 μg g−1, while the LOQs ranged between 0.60 and 12.50 μg g−1. Finally, the proposed protocol was implemented for the analysis of a wide variety of savory snack samples including commercial snacks from corn, potato chips, popcorns, puffed rice cake and crackers.
... Traditional methods of puffing create severe environmental hazards along with a risk of adherence of sand with the rice (Chinnaswamy & Bhattacharya, 1983;Hoke, Houšová, & Houška, 2005). Additionally, puffing can be achieved using specific techniques such as hot oil frying (Hoke et al., 2005), gun puffing (Hoke et al., 2005), and the hot air puffing method (Nath, Chattopadhyay, & Majumdar, 2007;Sweley, Rose, & Jackson, 2013;Ushakumari, Rastogi, & Malleshi, 2007;Virot & Ponomarenko, 2015;Zapotoczny, Markowski, Majewska, Ratajski, & Konopko, 2006). The implementation of advanced technologies is, therefore, crucial for producing healthy puffed rice in a convenient process. ...
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A genetic algorithm based on artificial neural network (ANN) modeling was developed for the microwave puffing of preconditioned rice. The microwave puffing method was analyzed in order to find out the effect of microwave power, puffing time, butter level, and sodium bicarbonate level on the expansion ratio and puffing percentage of puffed rice. ANN modeling was applied between the independent and dependent variables and 4‐7‐2 architecture was selected as the best ANN architecture with mean squared error value ranging between 1.138 and 1.839. The optimized conditions obtained from the hybrid ANN‐GA approach were 850 W of microwave power, 35 s of puffing time, 5.26% of butter, and 1.46% of sodium bicarbonate. The optimum combination of independent variables resulted in maximum expansion ratio and percentage puffing of 8.4 and 94.37%, respectively. The relative deviations between the experimental and ANN‐GA model predicted values for expansion ratio and percentage puffing were 1.42 and 1.04%, respectively. The micrograph analysis showed that the parboiled rice had closely packed swollen starch granules with a fused endosperm, while large porous structured vacuoles were found in puffed rice. This study would provide a simple and efficient way to obtain crispy puffed rice by using a domestic microwave oven. Practical Applications Microwave puffing produces low fat ready to eat healthy products than the deep fat fried product. The microwave generates rapid heat and mass transfer in the food product resulting in the puffed product of desirable porous structure. Evaluation of optimal microwave puffing conditions will produce puffed rice with high sensory value and nutritional value. On this basis, the present study emphasized the effects of processing parameters and the potential of two additives, that is, butter and sodium bicarbonate, for microwave puffing of rice. The impact of various processing and operating conditions of microwave puffing of rice was analyzed. This research would make a way to make puffed rice at the domestic level in a quicker and easier process. This process would develop a suitable package containing preconditioned rice kernel with butter and sodium bicarbonate to obtain ready to eat puffed rice by using a domestic microwave oven.
... In the hard kernel type, which is found in popcorn, the endosperm is primarily of a glassy nature. In soft kernels, the endosperm is mostly floury (Sweley et al., 2013), and the NIR spectra obtained in this study was largely able to highlight the differences related to the presence of a hard kernel in popcorn. ...
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One of the most important quality traits in popcorn breeding programs is the popping expansion (PE) capacity of the kernel, which is the ratio of the volume of the popcorn to the weight of the kernel. In this study, we evaluated whether near infrared spectroscopy (NIR spectroscopy) could be used as a tool in popcorn breeding programs to routinely predict and/or discriminate popcorn genotypes on the basis of their PE. Three generations (F1, F2, and F2:3) were developed in three planting seasons by manual cross-pollination and self-pollination. A total of 376 ears from the F2:3 generation were selected, shelled, and subjected to phenotypic analysis. Genetic variability was observed in the F2 and F2:3 generations, and their average PE value was 31.5 ± 6.7 mL.g-1. PE prediction models using partial least square (PLS) regression were developed, and the root mean square error of calibration (RMSEC) was 6.08 mL.g-1, while the coefficient of determination (RC2) was 0.26. The model developed by principal component analysis with quadratic discriminant analysis (PCA-QDA) was the best for discriminating the kernels with low PE (≤ 30 mL.g-1) from those with high PE (> 30 mL.g-1) with an accuracy of 78%, sensitivity of 81.2%, and specificity of 72.2%. Although NIR spectroscopy appears to be a promising non-destructive method for assessing the PE of intact popcorn kernels for narrow breeding populations, greater variability and larger sample sizes would help improve the robustness of the predictive and classificatory models.
... However, this mechanism depends on some factors intrinsic to the grains (Borras et al., 2006), and these can be affected during drying. The reduction of the popping yield and the expansion capacity of the red popcorn may be associated with the formation of cracks in the grains subjected to temperatures of 70 and 100 C. Pericarp integrity is an important requirement for expansion to occur (Sweley et al., 2013); thus, cracks can cause the internal pressure to be relieved at damaged locations before bursting, which reduces the popping yield and expansion capacity. Singh et al. (1997) evaluated the effect of damage on the popcorn grain through 2 mm-thick manual cuts on the endosperm and germ. ...
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In order to obtain popcorn grains with excellent popping properties and a high β‐carotene content, the drying kinetics were investigated, and response surface methodology was used to optimize the drying process of red popcorn at temperatures of 40, 70, and 100°C and air velocities of 0.5, 1.5, and 2.5 m/s. The Page equation satisfactorily described the drying kinetics of red popcorn. Both variables (temperature and air velocity) had a significant effect on the popping yield, expansion time, and β‐carotene content. For the expansion time, only the air velocity had a significant effect. Based on an established quality standard, the temperature range of 40 and 50°C and air velocity from 0.5 to 1.2 m/s provided popcorn grains with a popping yield, expansion capacity, and β‐carotene content above 7%, 9 mL/mL, and 7.4 mg/100 g, respectively, and an expansion time below 130 s. Practical applications The present work optimized of red popcorn grain drying and provides scientific support for obtaining a dry product with excellent popping properties and high nutritional value.
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Popcorn is a specialty corn with worldwide popularity as a snack. Despite having great market demand, genetic improvement in popping quality is limited, which is caused by the limited germplasm utilization and narrow genetic base. An assortment of diverse germplasm, their effective characterization and integration into popcorn breeding pipeline is the foundation for an efficient breeding program. Here, kernel characteristics, popping quality traits, and agro-morphological traits were evaluated across three locations on a diverse panel of 48 popcorn inbreds derived from diverse landraces and populations of exotic and indigenous origin. The variations due to genotypes, locations, and genotype × location interaction were highly significant. The popping quality traits recorded wide variation with a high coefficient of genotypic determination. The kernel dimensions, kernel density, test weight, and grain yield were negatively correlated with popping quality traits. Genotypes with rice-type kernels exhibited better popping quality than pearl-type kernels. Analysis of genotype × location (G×L) interaction identified two target locations for the key popping quality trait, popping expansion volume. PMI-PC-175, PMI-PC-187, PMI-PC-188, and PMI-PC-189 were identified as superior genotypes over checks for desirable popping quality, agronomic performance, and high grain yield. The contrasting inbreds for popping quality and flake shape (mushroom vs. butterfly) can be utilized for developing mapping populations to enhance our understanding of molecular aspects of popping quality traits. Further, the promising inbreds can be utilized in the genetic improvement of popcorn and crossed to develop superior popcorn hybrids. The results suggest a potential opportunity to establish an efficient popcorn breeding program. Keywords: Popping rate, germplasm, popping expansion volume, genotype × location interaction, popcorn market
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Background and objectives Popping beans are genotypes developed from crosses between nuña beans and common beans adapted to temperate climates. Toasted popping beans are a potential snack with a nutty flavor and malted milk ball‐like texture. Except for moisture content, the influence of other factors of raw beans on their popping efficiency has remained understudied. Thus, this study aimed to evaluate the proximate composition, functional properties, and their impact on the popping efficiency of 20 popping bean samples from different lines, harvest seasons, and locations. Findings Results showed significant differences ( P < 0.05) in physicochemical characteristics and functional properties among the samples, including differences in starch, protein, fiber, fat, moisture, and ash content. Water absorption index, water solubility index, and flour swelling power also significantly differed between samples. The highest popping efficiency was 98.3%, while the lowest was 24.0%, with no significant correlation between physicochemical characteristics and popping efficiency. However, the study did find a correlation between pericarp color and popping percentage. Conclusion There was no significant correlation between physicochemical characteristics and popping efficiency in popping beans. This article is protected by copyright. All rights reserved.
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The pursuit of reusing agribusiness residues towards decreasing their environmental impact has led to the study of its components to know their possible applications. The nejayote is the alkaline wastewater of different food products of nixtamalized corn. This study characterized the physicochemical properties of popcorn nejayote (NP) and determined its total phenolics content (TP) and antioxidant capacity by standard synthetic assays (ABTS and DPPH) and physiologically relevant ones (reducing power -RP-, hydroxyl radical scavenging activity -OH-, and iron chelation IRON). NP antioxidant capacity determined by ABTS, and DPPH methods were 387.9±0.7 and 419.3±2.9 mM Trolox equivalents (mM TE)/mL, respectively. The NP showed 296% RP compared to a control solution of coumaric acid (0.1 M). Also, the NP was obtained at 143% IRON compared to a control solution of caffeic acid (0.1 M). In the case of OH, values ranged from 27% to 45% compared with control solutions. TP was 0.26±0.006 μg gallic acid equivalents/mL (mg GAE/mL). Pearson's correlation analysis found that TP is correlated to the OH, IRON, and DPPH, while IRON activity correlates with OH and ABTS. And finally, OH correlated with DPPH. To the best of our knowledge, this study is NP's first antioxidant capacity report.
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Without chewing, the fresh popcorn dissolves immediately upon being put in the mouth. Such good taste decay dramatically with increasing the exposure time in air, especially in humid air. However, the involving mechanism of the saliva wetting the popcorn remains unclear. Here, it is revealed that the ultra‐fast wetting property of the fresh popcorn is the key for its good taste. For the fresh popcorn, the unique 3D throughout micro‐porous structure facilitates capillary flows both in‐plane and off‐plane at micro‐/nano‐ scale, and the water‐soluble crystalized starch further prompts the water spreading, which cooperatively leads to an immediate structural collapse. The unique ultra‐fast wetting of the fresh popcorn is therefore featured as the wetting with dissolving. After cooling down, the crystalized starch changes gradually into an insoluble amorphous state by absorbing water molecule, as is confirmed by the in situ XRD and infrared spectroscopy. As a result, the ultra‐fast wetting decays drastically with prolonging the in‐air exposure time, as well as the taste, which makes immediate cooking vital for the good taste. It is demonstrated that heating can partially restore the ultra‐fast wetting. It is envisioned that the result will inspire the innovative micro‐fabrication of various starch food by engineering the starch crystalline structure.
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Popcorn (Zea mays everta Sturt.) can explode popcorn flake for snack food when heated. In this study, a popcorn inbred line, N04 with small grain weight, and a dent corn Dan232 with large grain weight were re-sequenced and compared with the B73 reference genome, respectively. The genome variation information between N04 and Dan232 was obtained, including 0.95 million SNPS, 0.44 million INS and 0.49 million DEL. Combining the genome of Mexican landrace Palomero and dent maize inbred lines Zheng58, Chang7-2 and Mo17, 10,837 genes with sequence variation were identified between popcorn and dent corn. There were 308 unique genes found in the popcorn genome, which were mainly involved in metabolic processes, phosphorus metabolism, protein modification and other biological processes. A total of 318 differential genes were obtained by analyzing proteome and genomic data of kernel development of N04 and Dan232. And only 4 differential expression genes were found among ESTs, genome and proteome data simultaneously, which encode auxin-binding protein, amylase, pyruvate phosphate kinase and glucose phosphate adenylyltransferase, respectively. These results uncover the genome characteristics of popcorn, which will provide important information for studying the molecular mechanism of popping characteristics.
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Sorghum is the fifth most harvested crop worldwide, being the popped sorghum as one of the most common snacks in India and some Asian regions. Therefore, this study evaluated how the processing method influences the microstructure, volumetric and textural properties of popped sorghum microstructure, volumetric and textural properties. White sorghum “Paloma” variety (11% moisture) was assessed, which was popped using three processing methods: microwave, pan-frying, and hot salt-frying using three temperature levels. Volumetric and yield characteristics were evaluated for the popped kernels, as their microstructure and texture profile. The popped sorghum obtained through the hot salt-frying method had a microstructure composed of polygonal cells. Also, it showed the best volumetric characteristics (volume), good expansion index, and high process yield. Finally, the hot salt-frying method showed better textural features associated with the attributes of a satisfactory product for consumers.
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The superfood quinoa is an extremely nutritious and ancient pseudocereal grain particularly known for its protein quality and bioactive compounds, compared to other cereals. Quinoa seeds can be processed into a crispy, cellular-structured and expanded whole-grain snack product by low capital cost involving traditional sand puffing method. The study aims to statistically optimize the processing conditions for sand puffing of quinoa. The moisture-treated and salt-treated quinoa grains were mixed with a high-temperature sand bed for a predetermined time to induce grain expansion. Puffing conditions were optimized using Box-Behnken design by varying the factors such as moisture added (0.2-1.8 ml/10 g grains), salt concentration (0-1%), puffing temperature (200-240 ºC) and puffing time (20-60 s). It was found that measured response parameters like puffing yield, expansion ratio, flake size and overall acceptability of puffed quinoa significantly (p<0.05) increased with a decrease in moisture added and salt concentration, and increase in puffing temperature and puffing time. Bulk density of puffed quinoa had a negative correlation with puffing temperature and puffing time. The optimum condition of 0.2 ml moisture added/10 g grains, 0.2% salt concentration, 229ºC puffing temperature and 55 s puffing time was predicted to generate puffing yield of 86.23%, expansion ratio of 3.08, flake size of 8.21 mm3, bulk density of 0.36 g/ml and overall acceptability score of 8.65. The higher yield, three-fold expansion and superior sensory attributes of puffed quinoa achieved from optimized sand puffing condition would benefit the manufactures and be nutritious snack food for consumers to combat malnutrition.
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The influence of the cooking method on the elemental composition of popcorn, prepared according to the way it is consumed, was evaluated. Arsenic, calcium, cadmium, copper, iron, lead, magnesium, manganese, potassium, selenium, sodium and zinc levels were determined using atomic absorption spectrometry. Results showed that the losses after cooking varied considerably (2.9%–48.3%) depending on the element. A bioaccessibility study of cooked samples was also performed, using an in vitro approach. The most bioaccessible elements were sodium (77.4%–88.5%) and potassium (63.7%–81.8%), while considerably low values were observed for calcium (5.5%–13.7%) probably due to strong interactions with the matrix. The contribution to the Recommended Dietary Allowance was evaluated, finding an important coverage for selenium (36.7%–50.0%). Positive Pearson correlation coefficients were found for the pairs Cu/Fe, Cu/Mn, Fe/Mn Cu/K, Fe/K, K/Mn which can be explained by natural physiological mechanisms of the plant. To the best of our knowledge, this is the first study of bioaccessibility of essential elements in Uruguayan popcorn.
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Popcorn is different from other maize types with especially its popping ability. Popcorn has special place in human nutrition by reason of the fact that nutrient content. Evaluation of popcorn experimental hybrids in different geographical regions gives breeders valuable clues in selection best hybrids for the target environments. In the present study, 44 experimental hybrids plus 5 commercial checks total 49 popcorn crosses were tested in there different geographical regions of Turkey. The research was carried out in Samsun (Northern Turkey), Cankiri (Middle Anatolia) and Antalya (Mediterranean of Turkey) ecological conditions in 2016; Also quality studies of this research was carried out in Karaman in 2017. The field experiments were conducted in a 7×7 lattice design using three replications. Grain yield of the hybrids were determined in field experiments. Furthermore; popping volume, unpopped kernels ratio and kernel size as quality traits were examined. According to the results, almost ten hybrids have performed above standards. On the other hand, overall (field and laboratory) results of the study revealed that TBCM2015-41, 56, 62, 76 and TBCM2015-80 experimental hybrids were promising popcorn hybrids for the tested environments. Prominent variety candidates in the research will be tried to gain future agriculture of the country.
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Popcorn (Zea mays var. everta) has a higher commercial value than common maize, in addition to being a popular food among consumers. Today, there is a constant search for cultivars with superior performance for several traits of interest in the case of popcorn, yield and popping expansion. On this basis, this project proposes to characterize progenies of popcorn with different values of expansion capacity regarding chemical composition and micromorphology. Kernels from the fifth cycle (C5) of intrapopulation recurrent selection were evaluated. The progenies were selected based on the popping expansion volume of their kernels. The kernels were quantified for amylose and analyzed for starch granule arrangement and pericarp thickness by scanning electron microscopy. Progenies with low popping expansion volume (0 and 7 mL g-1) showed amylose contents of 21.24 and 20.18%, respectively; a less compact endosperm, with individual starch granules interspaced with empty spaces; and pericarp thickness between 40.94 and 38.99 µm, respectively. By contrast, progenies with high popping expansion volume (30 and 35 mL g-1) showed amylose contents of 23.92 and 26.10%; a vitreous endosperm; more-compact starch granules without empty spaces in between; and pericarp thickness between 107.66 and 107.84 µm. Progenies with higher popping expansion volume exhibited a thicker pericarp, a high amylose percentage and a more-compact endosperm, whereas those with the lower expansion volumes showed a thinner pericarp, a lower amylose percentage and individual starch granules.
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Popcorn is a popular snack food with higher grain value compared with “field corn” maize (Zea mays L.). In general, popcorn germplasm is less improved than common maize cultivars, with less favorable agronomic performance and greater susceptibility to pests, diseases, and lodging, especially in tropical environments. One approach to expanding and improving popcorn germplasm is to introduce favorable alleles for agronomic performance from field corn. If markers tagging quantitative trait loci (QTLs) associated with popping expansion were identified, they could be selected with markers to maintain popping expansion in breeding populations derived from crosses between field and popcorn germplasm. The objectives of this study were to identify single nucleotide polymorphism (SNP) markers and putative candidate genes associated with higher popping expansion in a diverse sample of popcorn and field corns relevant to Brazilian breeding programs. We applied a comprehensive genome‐wide association study (GWAS) for popping expansion, using 165,089 SNP markers in 183 inbred lines with 2 yr of trial data. Four SNPs were significantly associated with popping expansion, three of which were colocalized to previously reported meta‐QTLs, and one that was novel. Annotated genes closely linked to the associated SNPs were identified with functions related with starch content, which plays an important role in popping expansion quality. If these associations can be validated independently, they can be useful for breeders to select agronomically superior genotypes with greater popping expansion.
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Thirty six cultivars of corn ( Zea mays L.) and three of its relatives (northern teosinte, Tripsacum dactyloides L., and Coix lachryma-jobi L.) were evaluated for pericarp thickness and number of cell layers in the pericarp. Both traits were examined using a light microscope. Pericarp thickness ranged from 50 to 185 pm and cell layer number from 5 to 22 within the 36 cultivars; pericarp thickness and cell layer number were positively and highly significantly correlated ( r = 0.93**). The three relatives of corn had pericarps with 2 to 3 cell layers totaling 30 μm in thickness.
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A computer model for particle packing is of importance in both theories and applications. By taking a very different approach from existing packing algorithms, our digital packing algorithm – called DigiPac – is able to avoid many of the difficulties normally encountered by the conventional algorithms in dealing with non-spherical particles. Using the digital approach, it is easy to pack particles of arbitrary shapes and sizes into a container of any geometry. This paper briefly describes the digital packing algorithm, but the focus is on validation of the DigiPac model through several case studies involving mono-sized non-spherical particles and also powders with different size distributions. Packing densities from DigiPac simulations are compared with those measured experimentally by ourselves in some cases and in others with data published in the literature using other models. The results show a good agreement in all the cases, which enhances our confidence in DigiPac that despite being a geometrical packing algorithm with no explicit consideration of particle interactions, it is able to predict quite accurately the packing structure of particulates whose shapes are commonly encountered in both industry and everyday life.
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Three rice‐type popcorns (red, white and yellow) and one pearl‐type popcorn (yellow) were used in this study. All types were sized into three fractions (5 < D < 6 mm, 6 < D < 7 mm and D > 7 mm) by screening with round‐hole sieves. Samples were tested for popping quality and suitability for popping, and the sensory properties of the popcorns were evaluated. A popcorn popper with a maximum operating temperature of 226 °C was used for popping the samples (25 g). Both kernel type and size affected the expansion volume and the number of unpopped kernels. Yellow pearl‐type (YPT) and white rice‐type (WRT) popcorns showed good popping performance. The popping properties of the smallest‐sized kernels were better than those of the other fractions. Popcorn type significantly affected the flake size uniformity, flake shape uniformity, flake colour, crispness and taste of the products. Analysis of variance (ANOVA) and principal component analysis (PCA) showed that that kernel size was of great importance for the expansion volume, which was negatively correlated with number of unpopped kernels, 1000‐kernel weight and diameter ratio and positively correlated with flake size, kernels per 25 g, crispness and tenderness. © 2001 Society of Chemical Industry
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Response surface methodology was used to evaluate the effects of ingredients on popcorn popping characteristics. The effects of different ingredients on the expansion volume and unpopped kernel ratio of popcorn in a conventional popper and a microwave oven were evaluated and optimized by response surface methodology. The regression models were significant and had R2 value in the range of 0.919–0.956. The optimum levels of ingredients for microwave popping were 4.4% salt, 5.9% vegetable oil, 0% sodium bicarbonate and 16.4% butter, this formulation giving an expansion volume of 33.1 mL g−1. In the case of conventional popping, the maximum expansion volume of 37.3 mL g−1 was obtained for 3.5% salt, 6% vegetable oil, 0.10% sodium bicarbonate and 12.9% butter.
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This study investigated several independent variables affecting the expansion volume of microwave popcorn; (a) different hybrids were used, (b) hybrids were popped at different moisture contents, (c) microwave ovens with various wattages were employed, and (d) kernels were separated by size. The greatest expansion volume was achieved with Hunt-Wesson 214 at 11% moisture. Overall, the large-capacity bag and the 1000-watt microwave oven produced the greatest expansion volume. Medium-sized kernels produced the greatest expansion volume.
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Kernel hardness tests, test weight, seed size, and proximate composition tests varied in their ability to predict dent maize (Zea mays, L.) hybrids' alkaline processing, dry milling, and wet milling performance. Quality and processing tests varied among the eight yellow, dent maize hybrids and across five growing locations in Nebraska, USA. Dry milling performance was best predicted by kernel specific density and hardness measurements, especially the tangential abrasive dehulling device (TADD). Hardness tests were significantly impacted by kernel density, protein, and lipid contents, but not by total starch content. Wet milling yields were not highly predicted by any one test (r<0.5); however, wet milling and alkaline processing performance correlated with hardness measures, kernel density, and percent floaters. Neither kernel total starch or initial moisture content significantly correlated with wet milled starch yields. Lipid content correlated with steeped kernel moisture absorption. Percent moisture absorbed during alkaline processing correlated with nixtamal texture, but absorption during wet milled steeping did not influence steeped kernel texture. Breakage susceptibility was a good test for predicting alkaline cooking dry matter loss. Ease of pericarp removal was not related to any of the tests. Principle component analysis grouped kernel tests explaining kernel traits relevant to explaining processing variability. Both hybrid and environmental factors affected most measured traits.
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Two corn meals, one with good and one with poor expansion properties, were used to study the critical factors responsible for poor expansion during corn curl extrusion. Screening tests revealed that the corn meal with poor expansion had a slightly larger particle size. This sample also had a larger proportion of opaque particles compared to the corn meal with good expansion. Extrusion of coarse corn grits showed that larger particle size alone could cause poor expansion. Water diffusion tests showed that the sample containing more opaque particles was more competitive for water. As a result, in corn that contained both opaque and vitreous particles less water was available to the vitreous particles. The underplastisized (dry) vitreous particles remained glassy (unmelted) during extrusion, resulting in reduced expansion of the extrudates. The results suggest that addition of water to the conditioning cylinder of the extruder would overcome poor expansion.
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Test weight, specific gravity, kernel size, and kernel shape were quantified for twelve popcorn hybrids at twelve different kernel moisture contents. The effect of these properties on expansion volume of the popcorn upon popping was studied. Tables showing results are appended.
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The objective of this study was to identify and characterize different popped popcorn flake shapes, or polymorphisms, arising from a yellow butterfly popcorn hybrid (YP-213), and then to determine the impact of popcorn flake shape on composition and sensory characteristics. Kernels were popped using a microwave oven and visually sorted into three different polymorphisms depending on whether the appendages were expanded unilaterally, bilaterally, or multilaterally. When popped, 9.0 ± 3.1%, 71.2 ± 5.9%, and 12.3 ± 3.8% of kernels were expanded unilaterally, bilaterally, and multilaterally, respectively, while 7.6 ± 1.4% of kernels remained unpopped. Expansion volumes for unilaterally, bilaterally, and multilaterally expanded polymorphisms were 28.6 ± 3.84, 43.0 ± 0.84, and 53.5 ± 2.5 cm3/g, respectively. Unilateral popcorn flakes retained the most fat, saturated fat, and sodium, while multilaterally expanded flakes had the highest levels of protein, total carbohydrate, and popcorn-like aromatic pyrazines. Sensory evaluation revealed significant differences among polymorphisms for flavor and texture attributes, with the unilaterally expanded polymorphism receiving the highest overall product liking. These data show that different popcorn flake polymorphisms produced from a single hybrid of popcorn affect sensory and compositional profiles. More research is necessary to elucidate the factors that affect popcorn flake polymorphisms and support development of new varieties or techniques to produce the most desirable microwave popcorn.
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The objective of this study was to characterize the effect of hybrid and environment on physical and chemical characteristics of popcorn kernels that have shown importance in predicting end-use quality. Three popcorn hybrids grown in three different environments were tested for physiochemical attributes and popping performance. Hybrid had a significant effect on kernel sphericity, time-to-grind, dietary fiber, sugars, and starch. Environment effect alone affected total mineral content. Hybrid and environment main effects influenced test weight, tangential abrasive dehulling device index, thousand-kernel weight, total carbohydrates, and kernel protein content. Oil adherence to the bag averaged 15.8% and was proportional to oil amount added prior to microwave popping. Unpopped kernels averaged 11.4 ± 5.3%. Most unpopped kernels were observed to successfully pop when heated a second time in microwave tests. Expansion volume was 44.7 ± 3.7 and 47.3 ± 6.4 cm3/g, depending on the method of determination. Expansion volume was correlated (p < 0.05) with several kernel physiochemical parameters that were influenced by hybrid effect. Sphericity, thousand-weight, and total fat are physiochemical characteristics that appear to be good predictors (p < 0.05) of expansion volume.
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Cereal Chem. 83(1):86-92 The objective of this study was to determine the relationship between the amount and type of lipids, starch composition and structure, and storage proteins on popcorn expansion and to evaluate whether popcorns could be discriminated from other types of corn based on the protein elution parameters. Seven commercial Argentinean popcorn samples were used in the study and significant differences were observed in the popping volume of these popcorns. A significant negative correlation was observed between oleic acid and popping volume and a positive correlation was observed between linoleic acid and popping volume. Popcorn starch properties were significantly different from normal corn but no particular measured attribute of starch correlated with popping volume. α-Zein proteins and glutelins significantly correlated with popcorn expansion volume with R2 = 0.963 and 0.744, respectively. The elution patterns of corn proteins could also be used to discriminate between different types of corn including popcorn, dent, and flint corns.
Article
Cereal Chem. 82(1):53-59 The rate of popping of popcorn was measured in oil and in air. Kinetic data for lifetimes of individual kernels from a large population were obtained in oil at six constant temperatures (180-250°C) and also in an air-popper at 202°C. The data are characterized by an induction period, which is, significantly, followed by a first-order decrease in the number of unpopped kernels versus time. The activation energy for the first order process is 166.7 kJ/mol between 180 and 210°C, and 53.8 kJ/mol between 210 and 250°C. These data are consistent with a model that assumes 1) that the rate of heat transfer into a kernel follows Newton's law of cooling; 2) that in a sample of kernels there exists a distribution of critical pressures; 3) that for an individual kernel, the probability of popping is directly proportional to the difference between the internal aqueous vapor pressure and the kernel's critical pressure; and 4) that the measured rate constant at any temperature is an average overall of the kernels in the sample with critical pressures equal to or less than the inter- nal aqueous vapor pressure. Minimum popping temperatures predicted by the model are 181 ± 2°C (oil) and 187 ± 2°C (air), in good agreement with previously reported direct measurements.
Article
Improvement of expansion volume, defined as the volume of popped corn per gram of unpopped corn, generally is considered the most important objective of popcorn (Zea mays L.) breeding programs. Popcorn, however, generally is inferior to dent corn with respect to yield and other agronomic characteristics. Detailed information on the inheritance of expansion volume and grain yield in popcorn × dent corn crosses was not available in the literature. The objective of this study was to determine the inheritance of expansion volume and grain yield, including yield components, in two popcorn × dent corn crosses (...)
Article
(...) This study investigated the presence of a genotype×popping method interaction for expansion volume and its components in popcorn. Eleven commercial popcorn hybrids, one flint corn×popcorn inbred line cross, and one open-pollinated popcorn variety were grown in isolation in 1988. Seed harvested from each genotype was divided equally into large- and small-kernel samples that were evaluated for expansion volume, popped kernel (flake) size, and percent unpopped kernels in conventional and microwave popping. (...)
Article
During the popping of popcorn the pericarp acts as a pressure vessel. It was found that the initial break in the pericarp affects popped volume more radically than do any subsequent breaks. Popping occurs at about 177 °C, which is equivalent to a pressure of 135 psi inside the kernel. Most of the water in the kernel is superheated at the moment of popping and provides the driving force for expanding the kernel once the pericarp ruptures. At temperatures below 177 °C the proportion of kernels that have popped declines markedly. The scanning electron microscope was used to document changes occurring in the kernel as a result of popping. In the translucent endosperm the superheated water appears to vaporize into the hilum, expanding the starch to a thin film. In the opaque endosperm large voids are produced and the starch granules remain birefringent. The voids around the starch provide an alternative site into which the superheated water vaporizes. Thus, the starch granules are not expanded and retain their birefringence.
Article
Kernel number, individual kernel weight, individual kernel volume, crude fat, crude protein, reducing sugars, starch content, amylose/amylopectin ratio and fatty acid composition were determined for six popcorn hybrids, grown in Colorado or Nebraska and harvested in 1997. The popcorn hybrids were A358W, 353W, BKH, 019, 1601 and 5501. Also, popcorn hybrids were categorized based on their popped color and popped shape as hybrid types, where A358W and 353W were white butterfly-type popcorn hybrids, BKH and 019 were yellow butterfly-type hybrids and 1601 and 5501 were yellow mushroom-type hybrids. Yellow mushroom hybrids showed significantly fewer number of kernels than the white and yellow butterfly-type hybrids. The number of kernels per 250 g of popcorn hybrids at 14% moisture content ranged from 1454 to 2219. Individual kernel weight of the popcorn hybrids ranged from a low mean of 112.6 mg for hybrid 353W to a high mean of 172.0 mg for hybrid 1601. Individual kernel volume of popcorn hybrids containing 14% moisture ranged from a low mean of 0.130 cm3for hybrid 353W to a high mean of 0.200 cm3for hybrid 1601. The popcorn hybrids contained 3.8–4.6% crude fat, 8.1–10.5% crude protein, 0.07–0.23% reducing sugars and 61.0–67.9% starch, in which 27.0–28.5% of the starch was amylose. Individual kernel volume (size of the kernel) was correlated with starch content (r=0.84). Fat content was highly correlated with starch content (r=−0.82). Popcorn hybrids contained on an average approximately 12.6% palmitic, 2.0% stearic, 25.5% oleic, 58.4% linoleic and 1.5% linolenic acids, respectively. The major fatty acids in the popcorn hybrids were linoleic and oleic acids.
Article
Previous studies have shown that popping volume of popcorn is affected by water content, and that popping volume increases with an increase in water content up to an optimal value, and then the volume decreases with any additional moisture. The aim of this study was to explore the mechanism responsible for the peak in popping volume as a function of water content. Popcorn was equilibrated to various water contents from 6.7 to 16.5 g/100 g d.b. over salt solutions (aw0.33–0.82), and popped by an air popper. Maximal popping volume occurred at a water content of 15.5 g/100 g d.b. (aw=0.745 at room temperature) while the popping temperature dropped with increasing water content. Thermal analysis of the popcorn by DSC showed no significant effect of the moisture on the melting temperature orTg of the unpopped endosperm. However, the decrease of the pericarp melting temperature correlated with an increased water content. The results suggest that elevated water contents cause a rubbery collapse of the pericarp at lower temperature. The temperature of this melting event decreases by ∼7 °C over the 6–16.5 g/100 g moisture range. Thus, as the water content increases, the pressure in the kernel at the popping moment is lower, causing less expansion and lower final popped volume.
Article
Studies were undertaken to develop a coating system for popcorn in order to achieve maximum number of popped kernels during microwave heating. The effects of microwave power levels and different ingredients (hydrogenated oil, sodium chloride, butter, sodium bicarbonate) on popping behaviour of popcorn during microwave heating were studied using a central composite design. All the regression models were significant at the p < 0.025 level and showed R-2 value in the range of 89-92%. The models developed can be used as a tool to study popping behaviour of popcorn. Popcorn having more than 75% of popped kernels and lower than 0.05 g/cm(3) of bulk density can be achieved using 10% hydrogenated oil, 2% butter and 0.5% sodium chloride and heating popcorns at 70% power in a microwave oven with a magnetron having actual power output of 660 W and operating frequency of 2450 MHz.
Article
The major carbohydrate of tuber and root crops is starch, which accounts for 16–24% of their total weight. In recent years, substantial progress has been made in understanding the relationship between starch structure and physicochemical properties. However, these studies have been mainly on cereal starches. The present status of knowledge on the composition, structure, gelatinization retrogradation, digestibility and rheological properties of tuber and root starches is reviewed. In addition, present concepts of granule structure, gelatinization, retrogradation and rheology are also reviewed. Future research needs in the area of tuber and root starches are discussed.
Article
g, and The 5.16- to 5.56-mm fraction had the highest popping volume and the the number of UPKs ranged from 13 to 23. Statistical analyses indicated lowest number of unpopped kernels (UPKs); the 4.36- to 4.75-mm fraction that the popcorn genotype and kernel size significantly affected the had the lowest popping volume and the greatest number of UPKs. For popping volume and the number of UPKs. Popcorn has long been a favorite traditional snack food in the United States. Popping volume, defined as volume per unit of weight of a sample, is a primary characteristic of popcorn, since commercial buyers purchase it by weight and sell by bulk volume. Furthermore, popcorn texture (tenderness and crispness) is positively correlated with popping volume (Rooney and Serna- Saldivar 1987). Factors that affect popping volume are moisture content, popping temperature, kernel size and shape, variety or genotype, kernel density, drying condition, and kernel damage. Moisture content has been considered the most critical factor, because it affects the rate and extent of pressure buildup in starch granules (Eldredge and Lyerly 1943; Hoseney et al 1983). Dexter (1946), Bemis (1959), and Huelsen (1960) reported different values (13.5, 13, and 12.5%, respectively) for the optimum moisture content for maximum expansion. Eldredge and Lyerly (1943) stated that a moisture content between 12 and 13% provided the best popping. However, in a different report, Eldredge and Thomas (1959) claimed that 13-14% was the optimum moisture level. These differences imply that the optimum moisture content for maxi- mum popping volume is dependent on the popcorn tested, popping procedures, and the methods of measuring moisture content. Haugh et al (1976) indicated that the optimum moisture content was different for different hybrids of popcorn. In addition, the method of popping is expected to influence the optimum moisture content. Metzger et al (1989) found that air popping produced a higher volume than oil popping and that a greater moisture content was needed for hot-air popping. Physical properties of popcorn such as kernel size, shape, and density were found to affect the popping volume (Lyerly 1942; Richardson 1959). The smaller, shorter, and rounder kernels had higher popping volumes. Willier and Brunson (1927) also found that popping volume increased as kernel size decreased. Eldredge and Thomas (1959) reported that popcorn with a higher bulk density yielded a higher popping volume, which they believed was due to denser starch granules in the kernels. Haugh et al (1976), however, found that kernels from the butt location of the ear had the largest popping volume but the lowest specific gravity. The objectives of this study were to determine the effect of popcorn kernel size on the popping volume and the number of unpopped kernels (UPKs) of selected commercial genotypes.
Article
The amounts of horny and floury endosperm in popcorn kernels, as indicated by their measured areas over median longitudinal sections parallel and perpendicular to the face of the kernels (lateral and sagittal sections, respectively) were measured using a technique combining photography and planimetry. Correlations were sought between these measurements and indicators of popping performance in a microwave oven. The horny endosperm measured over the sagittal section was correlated positively with unpopped kernel ratio. Measurements from the lateral section were found to have better correlation with expansion volume. Expansion volume increased with decreasing area of floury endosperm. The same trend was found relative to the floury/horny endosperm ratio. Since the floury endosperm envelopes the germ, a larger germ area measured over the lateral section indicated a more symmetrical orientation of the floury endosperm within the popcorn kernel. Expansion volume increased with increasing germ area. While the results obtained were for only a limited number of popcorn cultivars and kernels, the data indicated that microwave popping performance is affected by the spatial orientation and proportion of the floury endosperm.
Article
In this study, the effects of moisture content and popping methods on popping quality of five popcorn genotypes were investigated. Each of the five genotypes was equilibrated to seven moisture levels ranging from 8% to 20% and was popped by microwave oven, hot-air popper, cooking pan with and without oil and salt. Genotype, moisture content, and popping method affected the expansion volume, flake size, and percentage of unpopped kernels. The highest popping quality, i.e. popping volume, flake size and the lowest percentage of unpopped kernels, were obtained from grains with a moisture content of 14%. The microwave oven gave the greatest flake size and percentage of unpopped kernels whereas the lowest expansion volume and flake size were obtained from the cooking pan popping with oil and salt. Genotype×moisture content, genotype×popping method, and moisture content×popping method interactions were also significant for investigated traits. As water content deviates from the optimum, the expansion volume and flake size declined significantly. In addition, hybrids with medium kernel size had higher values for the expansion volume and flake size. These values decreased dramatically in popping with oil and salt.
Article
Expansion volume, flake size, percentage of unpopped kernels, protein content, kernel size, test weight, 1000 kernel weight and sensory evaluation were determined for 12 commercial popcorn genotypes in this study. Statistically significant variations were found by ANOVA amongst the genotypes for all the variables examined. The expansion volume of popcorn genotypes varied between 18.50cm3g−1 and 35.25cm3g−1. Correlations amongst the variables as well as their direct and indirect effects on expansion volume were also calculated using the correlation and path coefficients analyses, respectively. In the examined characteristics, positive and statistically significant relationships were found between expansion volume and flake size, kernel size. Path coefficient analyses indicated that flake size (74.21%), 1000 kernel weight (39.88%), kernel size (20.56%), percentage of unpopped kernels (16.08%), protein content (6.46%) had a positive direct effect on expansion volume.
Article
Cereal Chem. 74(5):672-675 Popping characteristics, specifically expansion volume and popping time, were studied for damaged popcorn. A single variety of commercial undamaged yellow popcorn was separated into four size fractions (D < 4.36, 4.36 < D < 5.16, 5.16 < D < 5.95, and D > 5.95 mm) by screening with round-hole sieves. Kernels were damaged using a razor knife by either slicing a 2-mm diameter piece of the e ndosperm or the germ or by cutting through the pericarp and seed coat into the endosperm or the germ ≈2 mm. A total of five combinations of location and damage were studied (tip cap removed, side cut, side sliced, germ cut, and germ sliced) for each kernel size. A control sample with no damage was also analyzed for each size fraction. All of the damaged kernels (regardless of type of damage) popped, but they had expansion volumes 9.1-47.5% smaller than those of undamaged kernels. The expansion volume of damaged kernels increased by 52.5-85.7%, depending on the damage, when the size of the kernel increased from 5.95 mm. Removing the tip cap and slicing through the germ caused less loss of expansion vol- ume than did other types of damage. Damaged popcorn kernels had faster popping times (12.2-24.0 sec) than did undamaged kernels (30.9-34.6 sec). Popping times increased with increasing kernel size for all types of damage.