Peanut Maturity Research Articles

Measuring the Kinetics of Acetaldehyde, Ethanol, and Ethyl Acetate within Peanut Kernels During High Temperature Drying

The concentration of acetaldehyde, ethanol, and ethyl acetate was measured in NC 9 peanut kernels during drying. Mature (black class, hull scrape method) and immature (orange class) peanuts were dried at air temperatures of 35 and 40C. The concentration of acetaldehyde, ethanol, and ethyl acetate within the kernel increased during drying. The highest concentrations of acetaldehyde, ethanol, and ethyl acetate were observed in immature kernels dried at 40C. The rate of production of acetaldehyde and ethanol appeared to change in response to the same stimuli. The rate of production of ethyl acetate appeared to be proportional to the simultaneous concentration of ethanol. The concentration of ethanol in immature peanuts dried at 40C peaked 30 to 40 h into the drying process, then gradually decreased to near predrying levels. The ratio of acetaldehyde-to-ethanol-to-ethyl acetate during the drying process appeared to be a function of drying air temperature, peanut maturity, and peanut kernel moisture content.

Interaction of Early‐Season Herbicide Injury, Tobacco Thrips Injury, and Cultivar on Peanut

AbstractPeanut (Arachis hypogaea L.) can tolerate severe early‐season injury by tobacco thrips [Frankliniella fusca (Hinds)], and controlling populations usually is not recommended in the southeastern USA. Field observations, however, indicated that injury from early‐season thrips infestation may exacerbate injury caused to peanut by early postemergence herbicide application. Studies were conducted near Jay and Marianna, FL, during 1989 and 1990 to evaluate the interaction between peanut cultivar, preplant incorporated application of vernolate (S‐propyl dipropylcarbamothioate), postemergence application of alachlor [2‐chloro‐N‐(2,6‐diethylphenyl)‐N‐(methoxymethyl)acetamide] plus paraquat(1,1'‐dimethyl‐4,4'‐bipyridinium ion) and thrips suppression with foliar application of acephate (O,S‐dimethyl acetylphosphoroamidothioate). ‘Southern Runner’ was more susceptible than ‘Florunner’ to early‐season stress from insect and herbicide injury. Injury from preplant incorporated herbicide alone, postemergence herbicide alone, or thrips alone usually was not sufficient to cause long‐term damage to peanut growth or to adversely affect peanut maturity or yield. When two or all of these factors impacted peanut simultaneously, however, delays in crop maturity and reduced yields (up to 11%) were often observed. Early‐season suppression of tobacco thrips often alleviated the detrimental effects to peanut. Suppression of thrips populations should receive greater consideration in future integrated pest management programs of peanut to avoid interactions with early‐season herbicide stress, especially when growing Southern Runner.

Enzyme-Amplified Microtiter Plate Assay for Ethanol: Its Application to the Detection of Apparent Ethanol in Peanuts

A colorimetric microtiter plate assay amplified by aldehyde dehydrogenase, in the presence of alcohol dehydrogenase, nicotinamide adenine dinucleotide, diaphorase, and p-iodonitrotetrazolium violet was developed for detection of protein-bound apparent ethanol (i.e., ethanol and other primary alcohols) in peanuts of differing maturity and curing (stackpole) stages. Data showed that at each curing stage mature peanuts had a lower level of protein-bound ethanol than immature peanuts and that at each maturity stage the level of protein-bound ethanol decreased during curing. This change in the level of protein-bound ethanol suggests that peanut maturity and curing have an effect on the binding of ethanol to peanut proteins. The implication of this is that the extent of flavor binding might contribute to the consequent difference in flavors between mature/cured and immature/cured peanuts.

Relationship of Hull Mesocarp Color to Seed Germination and Vigor in Large-Seeded Virginia-Type Peanuts

Abstract Classification of peanuts (Arachis hypogaea L.) based on pod mesocarp color has become a popular means of estimating maturity of runner peanuts. This study was initiated to determine if the hull mesocarp color is related to seed maturity of virginia-type peanuts and to evaluate changes in quality as seed mature. Cultivars NC 7 and NC 9 peanuts were harvested by hand in 1990, 1991, and 1992. Pods were separated according to mesocarp color. Seed moisture content and dry weight within a maturity class varied with cultivar and production year. Germination of NC 7 seed grown in 1990 and 1992 increased as seed approached maturity. Immature NC 9 seed grown in 1991 and 1992 had substantially lower germination than seed from mature pods. There was no increase in germination during maturation of NC 7 seed harvested in 1991 or NC 9 from 1990. Seed leakage during imbibition, measured by electrical conductivity, decreased as seed matured. The lowest leakage levels occurred when seed had reached physiological maturity. Germination following accelerated aging (AA) increased as seed matured. Maximum AA germination of NC 7 occurred when seed had reached 77, 84, and 100% of their final dry weight in 1990, 1991, and 1992, respectively. NC 9 seed achieved maximum germination following AA after the seed amassed at least 90% of their final dry weight.

Peptide Mapping of Peanut Proteins: Identification of Peptides as Potential Indicators of Peanut Maturity

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPeptide Mapping of Peanut Proteins: Identification of Peptides as Potential Indicators of Peanut MaturitySi Yin Chung, Abul H. J. Ullah, and Timothy H. SandersCite this: J. Agric. Food Chem. 1994, 42, 3, 623–628Publication Date (Print):March 1, 1994Publication History Published online1 May 2002Published inissue 1 March 1994https://doi.org/10.1021/jf00039a004RIGHTS & PERMISSIONSArticle Views115Altmetric-Citations5LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (685 KB) Get e-Alerts Get e-Alerts

Confirmation of sugars and reductones in complex peanut flavor precursor extracts by ion chromatography and methylation analysis

As confirmation of ion chromatographic determination of sugars and reductones in complex mixtures of peanut flavor precursors, extracts from defatted samples were derivatized as methylated alditol acetates to identify and semiquantitate them by GC-MS. To obtain maximum information about a sugar/reductone sample, the ion chromatography/integrated pulsed amperometric detection (I.C.-I.P.A.D.) data from carbohydrate extracts (80% ethanol) of defatted raw peanuts were further elucidated by GC-MS chromatograms of the derivatives. The technique was tested on a set of samples from one crop year representing stages of peanut maturity and turnover of metabolites during postharvest maturation and curing. Although there are many interfering substances in the ion chromatography such as amino acids, peptides, tannin, and carboxylic acids, the GC-MS total ion chromatograms of the characteristic methylated derivatives confirm relative quantities as well as identities of the reductone/sugar components separated as ion chromatography peaks. The results indicated depletion of sugars and reductones from immature peanuts during the curing process and stabilization of mature peanuts at a much lower level of reactive reductone precursors. The present study should also be applicable in food chemistry to other flavor precursor studies involving mixtures of sugars and reductones.

Maturity Detection in Peanuts (Arachis Hypogaea L.) Using Machine Vision

The flavor of shelled peanuts (Arachis hypogaea L.) is dependent on several factors including variety, growing conditions, post harvest operations, and maturity of the crop at harvest. At harvest, the peanut crop will have kernels in different stages of development due to the plants indeterminate fruiting nature. The maturity of individual peanut kernels can be determined by surface texture characteristics. However, at present, there is no automated method for separating peanut kernels by maturity. To facilitate development of a method, peanuts were hand classified into three maturity groupings (mature, mid-mature, and immature). A machine vision algorithm was developed to find useful surface texture descriptors for detecting each peanut maturity group. A descriptor derived from the gradient image of a peanut was found to be most useful in identifying peanuts of the mid-mature and immature groups in three market size classifications (jumbo, medium, and No. 1) when either white background or black background and red filter conditions were used. The gray level histogram characterization of peanut provided some information but additional experimentation will be necessary to derive texture descriptors useful for maturity sorting. Vision analysis of the gradient image appears as a promising technique for the development of an automated peanut maturity detection system.

Determination of pod and crop maturity for peanuts using percent pod-fill

A simple method for determining pod and crop maturity for peanuts (Arachis hypogaea L.) was developed using percent pod-fill (PF) — the percentage of green-pod volume that is seed. Peanut samples were collected 99–141 days after planting (DAP) for 3 yr from two soil types in the eastern Caribbean. PF of the composite pods and of the individual maturity classes from each treatment was determined. ANOVA, significance of means separation and correlation coefficients were computed. The results from the composite samples were correlated with optimum reaping time (ORT) established from the shellout method. ORT occurred 117–141 DAP. PF rate varied with season and soil type, but PF values for mature pods and for composite pods at ORT were independent of pod size, season and soil type. PF of mature pods was 41.5 ± 1.3% and was significantly different from that of other maturity classes. PF for composite pods at ORT was 38.2 ± 2.2% and was significantly different from PF values before ORT. The results indicated that percent pod-fill could be a reliable indicator of pod and crop maturity for peanuts.Key words: Arachis hypogaea, peanut maturity, pod-fill, maturity index

Maturity and roasting of peanuts as related to precursors of roasted flavor

Etude de l'arome de pâtes d'arachides preparees a partir d'arachides recoltees a 5 stades de maturite et grillees ou non avant transformation. Identification des principaux polypeptides caracteristiques de la flaveur du gout de grille

The relationship of peanut maturity to 2‐methylpropanal in headspace volatiles

AbstractHeadspace volatiles from peanuts of five consecutive maturity classes from three soil temperatures were determined to evaluate the relationship of peanut maturity and 2‐methylpropanal. Cured, ground peanuts were held in closed vials for 30 min at 150 C before headspace sampling. Quantitation as percent of total volatiles and ppm in the peanuts revealed a decrease in 2‐methylpropanal as peanuts matured regardless of seed size within maturity class. From peanut lots in which maturity‐size relationships had been determined, headspace analysis of commercial sized lots indicated that the concentration of 2‐methylpropanal was related to the maturity distribution (percent of each maturity class) within each sized lot. These data/techniques may have application in estimating lot‐to‐lot maturity‐related peanut flavor/quality potential.

Peanut hull flavonoids: their relationship with peanut maturity

Etude, en fonction du stade de maturation, de la teneur totale et de la proportion relative des trois principaux flavonoides, parallelement a la couleur des teguments. Interet pour la definition de la date de recolte

Adaptability of the Arginine Maturity Index Method To Virginia Type Peanuts in North Carolina1

Abstract The Arginine Maturity Index (AMI)- method for estimation of optimum maturity and highest quality of peanuts was evaluated in a two-year research station study (1977 and 1978) of large-seeded Virginia type peanuts grown in North Carolina. A one year study was conducted on farms in seven North Carolina counties in 1978. Samples were collected weekly from both the research station and farms and analyzed for arginine by the modified Sakaguchi reaction. Maximum yield corresponded to minimum AMI values for each cultivar in 1977 and for the NC 5 cultivar in 1978 in the research station study. Prediction curves were derived from each cultivar for each year using a quadratic polyonomial equation. Large differences in AMI data existed between 1977 and 1978 and between cultivars in 1978 at early harvest dates; however, near minimum AMI values, all six curves appear to be similar. AMI and yield data obtained from individual county farms fluctuated throughout the growing season. Generally, higher AMI values were observed for Virginia type than have been reported for Spanish type peanuts. Using the prediction curve derived in Georgia, and subtracting one week, predicted digging dates were within 4 days of the date of maximum dollar return per ha in five of the seven counties. Based on previous experience, the farm data of six counties (with the exception of Nash), was used to derive a tentative optimum harvest prediction equation for North Carolina.

Peanut Maturity Method Evaluations. I. Southeast

Abstract Arginine maturity index, methanol extract, shellout, and seed-hull maturity index methods of determining peanut (Arachis hypogaea L.) maturity were compared. Peanuts from four planting dates in 1978 were used. The comparisons showed that some of the methods are affected by date of planting and environmental factors, such as drought stress. Under the conditions of this test, the seed-hull maturity index and shellout were the most consistent indicators of the optimum yield period in 1978.

A METHOD FOR ESTIMATING PEANUT MATURITY

ABSTRACTOver the years, peanut maturity estimations have been based largely on subjective measurements. This paper reports a 3‐yr study of an objective method based on the tight transmittance measurement of a methanolic extract of freshly‐dug peanut pods which is both rapid and simple in operation and adaptable for field use. Results in 1975, 1976 and 1977 showed that the light transmittance of the methanolic extract correlated with the age of peanuts and dollar return per acre. Data also indicated that solar radiation, particularly during the fist 75 days of growth, may affect peanut maturity.

The Seed-Hull Weight Ratio as an Index of Peanut Maturity1,2

Abstract A simple, quantitative method was developed to determine peanut (Arachis hypogaea L.) maturity. The method is based on the changing seed-hull weight ratio during maturation of the fruit. The ratio or maturity index was determined for fresh as well as air-dried pods, and these ratios correlated well with a physiological maturity index. The relationship between arginine maturity index and the air-dried seed-hull maturity index (DMI) was also determined, and the two indexes were negatively correlated. The DMI values across nine planting and eight harvest dates over a 2-year period showed that DMI could be applied to estimate average peanut seed maturity under field harvest conditions. The two peanut varieties tested, Florigiant and Florunner, were found to differ in maxmum DMI values. The study also showed that peanut seed weight increased with maturity then decreased after full maturity.

Changes in Tannin-Like Compounds of Peanut Fruit Parts During Maturation1

Abstract This study served a twofold purpose in that it investigated the relationship of tannins to maturity of peanuts and provided some information on the possible importance of tannins in resistance of peanuts to invasion by various fungi. Peanut fruits were separated into selected physiological maturity stages and divided into hull, seed coat and seed. The fruit parts in each maturity stage were analyzed for tannin using Folin-Denis reagent. Examination of physical and chemical characteristics of hull and seed coat tannins confirmed they are both condensed tannins. Presented as mg tannin per fruit part, hull tannins increased significantly after stage 9, seed coat tannins increased significantly to stage 9 then decreased, and seed tannins did not change. Fruit parts of cured peanuts containing several maturity stages were similar in tannin content to the more mature uncured fruit parts. Calculated as % fresh weight, tannins in the hull and seed coat were significantly higher in the three most mature stages. The results show a close relationship of tannin and maturity and also indicate that tannin concentrations may be sufficient to provide some measure of resistance to microbial attack.

Internal Pericarp Color as a Subjective Maturity Index for Peanut Breeding1

Abstract Fruit of 10 peanut (Arachis hypogaea L.) genotypes differing in botanical type and geographical source were evaluated to establish parameters for making reliable maturity determinations on the basis of internal pericarp color (IPC), and to compare the IPC, kernel density (KD) and arginine maturity index (AMI) methods of estimating peanut maturity. Kernels from fruits with detectable, non-disease related internal pericarp darkening were significantly lower in density than kernels from fruits without internal pericarp darkening. No difference in density was detected between kernels from fruits differing in intensity of internal pericarp darkening. In general, two-seeded fruits with detectable non-disease related darkening in at least one orbital of the pericarp were mature, whereas fruits with no internal pericarp darkening were immature. Mature fruit percentages were determined on sample sizes of 25, 50, 75, and 100 fruits. Although standard errors were consistently high for 25-fruit samples, means and standard errors were similar for sample sizes of 50, 75, and 100 fruits, indicating that estimates based on 50-fruit samples were reliable. Post-harvest stability of IPC was evaluated from determinations made on five dates at 30-day intervals. IPC did not change sufficiently during the 120 day period to affect the maturity estimates. Kernel samples classified as mature by the IPC method were significantly lower in density and free arginine content than kernels classified as immature. Correlations among maturity estimates using the IPC, KD and AMI methods were highly significant, with all coefficients exceeding 0.95. The results indicate that peanut samples can be evaluated reliably for maturity by subjective classification of IPC. Maturity estimates on the basis of IPC were as effective as those determined using either the KD or AMI methods. The IPC method requires no sophisticated equipment and it is simple, rapid and nonsacrificial which makes it particularly useful in breeding programs involving large numbers of maturity determinations.