Protein extractability of almond (Prunus amygdalus,batsch) seed

Studies were carried out on protein solubility of almond meal in several solvents, by varying some factors that govern the efficiency of protein extraction. Concentrations of sodium hydroxide in the range 0.025 to 0.1M extracted most of the protein in almond meal. The rate of stirring had an effect on protein extraction. Increasing the temperature to about 50°C enhanced protein solubility when extractions were carried out using 0.05M NaOH solution. The most efficient solvent: meal ratio was found to be 2000:1 (vol:wt) for a single extraction. Almond proteins displayed a markedly different pH-nitrogen solubility profile in salt solutions, showing minimal solubility at an acidic pH (pH 3), with a sharp rise in solubility to a maximum at neutrality.     

Chemical composition of hulls of the sweet almond (Prunus amygdalus)

Determination of moisture, crude fibre, fat, ash, total nitrogen and carbohydrates was carried out on almond hulls. The contents of P, K, Mg, Cu, Zn, Fe, Mn, NO₃- and B were also determined. Amino acid composition was established. The results are compared with analytical data on almond nuts.     

A chemical study of the protein fraction of mediterranean sweet almond varieties (Prunus amygdalus)

Summary The protein contents and amino-acid compositions of five Mediterranean almond varieties were determined. The protein contents were between 18 and 24 g/100 g of almond, according to variety. The content of each amino-acid, expressed in g/100 g of protein, was similar in all varieties. The essential amino-acid composition was compared with the FAO pattern of amino-acid requirements and to the protein of milk and eggs. Percentages of albumins, globulins, glutelins and prolamines were also determined.

---

Eine chemische Studie der Proteinfraktion mediterraner Süßmandelvarietaten (Prunus amygdalus)

Zusammenfassung Der Proteingehalt and die Aminosäurenzusammensetzung von fünf mediterranen Mandelvarietäten wurden bestimmt. Der Proteingehalt liegt je nach Varietät zwischen 18 and 24 g/100 g Mandeln. Der Gehalt an jeder einzelnen Aminosäure, ausgedrückt in g/100 g Protein, ist in allen Varietäten ähn-lich. Außerdem wurde der Prozentgehalt an Albumin, Globulin, Glutelin and Prolamin bestimmt.

     

Mineral composition of almond varieties (prunus amygdalus)

Summary The contents of all elements considered essential for plants were determined on seven Mediterranean almond varieties. Atomic absorption, colorimetry, turbidimetry and ion selective electrode procedures were used. The average contents of macronutrients and micronutrients in the almond were determined to be 1957 and 23.2 mg/100 g respectively. Rectilinear relationships between P and Ca, Cl and Na and N and Cu were found.

---

Mineralstoffzusammensetzung verschiedener Mandelarten (Prunus amygdalus)

Zusammenfassung Der Gehalt aller wesentlichen Elemente wurde in sieben Mandelarten des Mittelmeergebietes bestimmt. Hierfür wurden die analytischen Methoden der Atomabsorption, der Colorimetrie, der Trübungsmessung und selektive Elektrodenverfahren verwendet. Die durchschnittlichen Gehalte der Makrobzw. Mikronährstoffe sind 1957 bzw. 23,2 mg/100 g Mandel. Lineare Beziehungen wurden bei den Gehalten von P and Ca, Cl and Na bzw. N und Cu gefunden.

     

Effect of γ-irradiation on the physicochemical and sensory properties of raw unpeeled almond kernels (Prunus dulcis)

The present study evaluated the quality of raw unpeeled almonds as a function of irradiation dose in order to determine dose levels causing minimal undesirable changes to almonds. Physicochemical (color, peroxide value, hexanal content, fatty acid composition, volatile compounds) and sensory (color, texture, odor, taste) properties of almonds were determined as a function of irradiation dose.Results showed a ten-fold increase in peroxide value (PV) after irradiation at a dose of 7 kGy. A small but statistically significant (p < 0.05) change was observed in hexanal concentration as a result of irradiation. No statistically significant (p > 0.05) changes were recorded in polyunsaturated fatty acids (PUFA) up to a dose of 7 kGy while monounsaturated fatty acids (MUFA) decreased manifested as a respective increase in saturated fatty acids (SFA) up to 3 kGy. Volatile compounds such as aldehydes, ketones and alcohols increased with increasing irradiation dose indicating enhanced lipid oxidation. Color parameter L^? decreased (p < 0.05) at doses > 3 kGy while color parameters a^? and b^? remained unaffected by irradiation. Sensory analysis showed that almonds remained organoleptically acceptable up to a dose of 3 kGy.Industrial Relevance: Irradiation is very efficient in controlling insects and growth of aflatogenic Aspergillus spp. in dry nuts.     

In vitro antioxidant, antimicrobial, and antitumor activities of bitter almond and sweet apricot (Prunus armeniaca L.) kernels

The aim of this study was to investigate in vitro antioxidant, antimicrobial, and antitumor activities of water, methanol, and ethanol extracts of sweet apricot and bitter almond kernels. The fruit extracts were evaluated for their antioxidant activities using various antioxidant methodologies including phosphomolybdenum assay (total antioxidant capacity), free radical scavenging assay, ferric ion reducing power, and β-carotene/linoleic acid bleaching test system. The antioxidant capacity of the sweet apricot kernels was better than those recorded for bitter almond ones. The highest total antioxidant activity (59.53 mg/g dry extract), ferric ion reducing power (1.626), antioxidant index (67%), total phenolic content (3.290 mg/g dry extract), and total lycopene content (4.70mg/mL) were detected in the aqueous extract of sweet apricot kernels. The antimicrobial activities of the above extracts were also tested against some pathogenic microorganisms using a disc-diffusion method. Additionally, the extracts of sweet apricot and bitter almond kernels could inhibit the growth of human breast (MCF-7), colon (HCT-116), and hepatocellular (Hep-G2) carcinoma cell lines in a dose-dependent manner with different sensitivity between cell lines. The overall results indicate promising baseline information for the potential uses of apricot (Prunus armeniaca L.) fruit extracts in the treatment of infectious diseases and tumors.     

Effect of irradiation, active and modified atmosphere packaging, container oxygen barrier and storage conditions on the physicochemical and sensory properties of raw unpeeled almond kernels (Prunus dulcis)

BACKGROUND: The present study investigated the effect of irradiation, active and modified atmosphere packaging, and storage conditions on quality retention of raw, whole, unpeeled almonds. Almond kernels were packaged in barrier and high‐barrier pouches, under N₂ or with an O₂ absorber and stored either under fluorescent lighting or in the dark at 20 °C for 12 months. Quality parameters monitored were peroxide value, hexanal content, colour, fatty acid composition and volatile compounds. Of the sensory attributes colour, texture, odour and taste were evaluated. RESULTS: Peroxide value and hexanal increased with dose of irradiation and storage time. Irradiation resulted in a decrease of polyunsaturated and monounsaturated fatty acids during storage with a parallel increase of saturated fatty acids. Volatile compounds were not affected by irradiation but increased with storage time indicating enhanced lipid oxidation. Colour parameters of samples remained unaffected immediately after irradiation. For samples packaged under a N₂, atmosphere L* and b* values decreased during storage with a parallel increase of value a* resulting to gradual product darkening especially in irradiated samples. CONCLUSION: Non‐irradiated almonds retained acceptable quality for ca. 12 months stored at 20 °C with the O₂ absorber irrespective of lighting conditions and packaging material oxygen barrier. The respective shelf life for samples irradiated at 1.0 kGy was 12 months packaged in PET‐SiOx//LDPE irrespective of lighting conditions and 12 months for samples irradiated at 3 kGy packaged in PET‐SiOx//LDPE stored in the dark. Copyright © 2010 Society of Chemical Industry     

Dietary fibre and components of the nitrogen-free extract of almond kernels

Determinations of neutral and acid detergent fibre residues (NDF and ADF), hemicellulose, cellulose and lignin in almond nuts (Prunus amygdalus) were carried out. The NDF content was about 5% while the crude fibre content was only approximately 2%. The composition of several components of nitrogen-free extract (NFE) such as soluble sugars, starch, gums and mucilages and pectins were also determined, and the results are discussed.     

IgE-Binding Proteins in Almonds (Prunus amygdalus); Identification by Immunoblotting with Sera from Almond-Allergic Adults

The allergenicity of three raw almond varieties (Nonpareil, Mission and Carmel) and three types of processed almonds (blanched, blanched-roasted, and almond butter) were examined and compared by immunoblotting using sera eight almond-allergic individuals. Serum from the 8 individuals exhibited unique IgE-binding patterns with most of the binding activity occurring with proteins of molecular weights between 30,000 and 70,000 daltons. Two major allergens were identified with molecular weights of ca 70,000 and 45,000–50,000 daltons, with each of these proteins binding to sera from 4 of the 8 allergic individuals. The immunoreactivity of the larger one was reduced by heat processing, while the smaller one was not affected.     

Purification,structural data and biological properties of polysaccharide from Prunus amygdalus gum

This work demonstrates the efficiency of almond gum polysaccharides (AGPs) as bioactive compounds. AGPs were first extracted using H₂O₂, in the presence of NaOH, at different times and temperatures. The optimal extraction conditions were 4% H₂O₂ and 2 N NaOH, for 7 h at 50 °C, leading to an extraction yield of 58.2% (w/w). After a purification step, the retained AGPs were characterised using high‐performance liquid chromatography showing a molecular weight of 99.3 kDa. The monosaccharide composition of AGPs were assessed using gas chromatography–mass spectrometry. AGPs were found to be a complex heteropolysaccharide with a repeating unit mainly composed of galactose, arabinose, xylose, mannose, rhamnose, and glucuronic acid with the respective ratios: 45:26:7:10:1:11. The acidic nature of the polysaccharide is due to the presence of glucuronic acid. Total antioxidant activity, free radical‐scavenging activity and reducing power assay of AGPs were investigated. The obtained results showed high antioxidant activities of AGPs. Furthermore, beyond 60 mg mL^?1, AGPs exhibited bacterial growth inhibition for five pathogenic strains: Escherichia coli, Staphylococcus aureus, Enterococcus feacalis, Pseudomonas aeruginosa and Salmonella typhimurium.     

Stack ensembled model to measure size and mass of almond kernels

After harvesting almond crop, accurate measurement of almond kernel sizes is a significant specification to plan, develop and enhance almond processing operations. The size and mass of the individual almond kernels are vital parameters usually associated with almond quality and yield. In this study, we propose a novel methodology that combines image processing and machine-learning ensemble that accurately measures the size and mass of whole raw almond kernels (classification—Nonpareil) simultaneously. We have developed an image-processing algorithm using recursive method to identify the individual almond kernels from an image and estimate the size of the kernels based on the occupied pixels by a kernel. The number of pixels representing an almond kernel was used as its digital fingerprint to predict its size and mass. Various popular machine learning (ML) models were implemented to build a stacked ensemble model (SEM), predicting the mass of the individual almond kernels based on the features derived from the pixels of the individual kernels in the image. The prediction accuracy and robustness of image processing and SEM were analyzed using uncertainty quantification. The mean error in estimating the average length of 1,000 almond kernel was 3.12%. Similarly, mean errors associated with predicting the 1,000 kernel mass were 0.63%. The developed algorithm in almond imaging in this study can be used to facilitate a rapid almond yield and quality appraisals.     

Policosanol distribution and accumulation in developing corn kernels

Policosanol is a mixture of long-chain primary aliphatic alcohols. The policosanol composition of whole corn kernel was determined in three varieties of corn (Astro, GH2547, Local). The total policosanol content of GH2547 (20.5 mg/kg of dry weight) was higher than those of Local (16.6 mg/kg) and Astro (15.2 mg/kg). The major policosanol components of whole corn kernel were dotriacontanol, triacontanol and tetracosanol. The distribution of policosanol in the germ, endosperm and pericarp of corn kernels was also determined. Corn pericarp had higher contents of policosanols (72.7–110.9 mg/kg) than the endosperm (4.0–16.2 mg/kg) and germ (19.3–37.1 mg/kg) fractions. Corn pericarp policosanol was mainly triacontanol (33.63–46.29 mg/kg), dotriacontanol (22.31–39.46 mg/kg) and octacosanol (8.13–14.0 mg/kg). In contrast, the corn germ fraction contained mostly dotriacontanol (more than 50%) and no triacontanol. The main components of corn endosperm policosanol were triacontanol and hexacosanol. The level of tetracosanol was highest in the germ fraction and lowest in the endosperm fraction. The greatest change in policosanol content (expressed as mg/100 g of oil) occurred during the early stages of corn kernel development. Although the structures of the alcohol constituents of policosanol are similar, their patterns of accumulation were different. The highest levels of octacosanol and dotriacontanol were detected at 20 days after pollination (DAP) followed by a rapid decrease between 20 and 30 DAP. Triacontanol levels decreased rapidly between 10 and 40 DAP, and then remained nearly constant.     

Survival of Salmonella Enteritidis PT 30 on inoculated almond kernels in hot water treatments

Almonds are blanched by exposure to hot water or steam-injected water to remove the pellicle (skin) from the kernel. This study evaluated the survival of Salmonella Enteritidis PT 30, Salmonella Senftenberg 775W and Enterococcus faecalis on whole raw almond kernels exposed to hot water. Whole, inoculated (7 to 9 log CFU/g) Nonpareil almonds (40 g) were submerged in 25 L of water maintained at 60, 70, 80 and 88 °C. Almonds were heated for up to 12 min, drained for 2 s, and transferred to 80 mL of cold (4 °C) tryptic soy broth. Almonds in broth were stomached at high speed for 2 min, serially diluted, plated onto tryptic soy and bismuth sulfite agars (Salmonella) or bile esculin agar (Enterococcus) and incubated at 37 °C for 24 and 48 h, respectively. D values of 2.6, 1.2, 0.75 and 0.39 min were calculated for exposure of S. Enteritidis PT 30 to water at 60, 70, 80 and 88 °C, respectively; the calculated z value was 35 C°. D values determined for Salmonella Senftenberg 775W and E. faecalis at 88 °C were 0.37 and 0.36 min, respectively. Neither Salmonella serovar could be recovered by enrichment of 1-g samples after almonds inoculated at 5 log CFU/g were heated at 88 °C for 2 min. These data will be useful to validate almond industry blanching processes.     

Effect of salting and roasting on the lipids of Iranian pistachio kernels

The simple lipids which make up 95% total lipids of Iranian pistachio kernels were identified as sterols and their esters; mono-, di- and tri-glycerides; and free fatty acids while the complex lipids were sterolglycosides; mono- and di-galactosyldiglycerides; cardiolipin, phosphatidyl-choline, -ethanolamine, -serine and -inositol; sphingolipid and phosphatidic acid. After salting and roasting, there was an increase in free fatty acids and in phosphatidic acid. Total fatty acids made up of C14:0, C16:0, C18:1, C18:2, C18:3 and C20:O were not significantly altered after roasting, nor was the iodine value, nor the malonaldehyde content. However, the peroxide value was increased.