Discrimination of storage conditions and freshness in virgin olive oil

Virgin olive oil samples stored in the light at ambient temperature, in the dark at ambient temperature, and at low temperature in the dark for 12 months both with and without headspace were separated into recognizable patterns with stepwise linear discriminant analysis. The discrimination with variables volatile and phenolic compounds, free fatty acid (FFA), peroxide values, K232, and K270 revealed a departure of stored oil from freshness and showed significant (p < 0.01) differences between storage conditions. Virgin olive oil stored at low temperature had characteristics closest to fresh oil while oil stored in the light showed the largest departure from freshness. Parameters that exclusively and significantly (p < 0.01) discriminated storage conditions were identified as potential markers of the storage condition. In the presence of oxygen, hexanal was a marker of storage in the light, FFA was a marker for dark storage, and markers of low-temperature storage were acetic acid and pentanal. In the absence of oxygen, octane was the marker for storage in the light whereas tyrosol and hexanol were markers of virgin olive oil stored in the dark, with no marker indicative of low-temperature storage. E-2-Hexenal, K232, and K270 were identified as markers of virgin olive oil freshness.     

Temporal changes in chemical properties of air‐dried stored soils and their interpretation for long‐term experiments

The usefulness of stored soils from long‐term experiments is often questioned because of changes that might occur during storage. We examined changes during long‐term storage (8–69 years) in the chemical properties of soils with a range of pH values (3.4–8.1 in water) from woodland and grassland experiments at Rothamsted Experimental Station in the UK. No significant changes during storage were measured for total C and N. Large but erratic changes in exchangeable Na⁺ content between 1959 and 1991 were probably caused by contamination of the 1959 samples by perspiration and from sodium‐based glassware. Exchangeable K⁺ increased during storage but only by a small amount. Small changes in exchangeable Ca²⁺ and Mg²⁺ were measured in some samples but not in others. Generally the amount of exchangeable cations increased slightly during storage. This is probably linked to the decreases of 0.4 units in the pH of acid soils, which we attribute to the hydrolysis of approximately 0.25% of the exchangeable Al³⁺. A doubling of the amount of exchangeable Mn²⁺ during storage for 32 years was probably caused by re‐equilibration of Mn species. The most practicable way to prepare soil samples for long‐term storage is to dry them in air. However, those who study changes in soil by re‐analysing samples of the soil stored for a long time must (i) use the same methods of analysis, or (ii) demonstrate that different methods lead to the same results, and (iii) know what changes can arise during storage.     

Storage of Wheat Grains at Elevated Temperatures Increases Solubilization of Glutenin Subunits

Grains of two wheat (Triticum aestivum L.) cultivars, Sunco and Sunsoft, were stored at 4°C and 30°C for 270 days to examine changes in proteins during storage. When whole meal flour extracted from the grains was analyzed using an unfractionated protein extraction procedure, no significant changes were found in protein content or SDS‐PAGE profile for either cultivar in samples stored at 30°C compared with those stored at 4°C. Fractionation of the flour samples from stored grain into soluble and insoluble proteins revealed increases in soluble protein content for both cultivars stored at 30°C compared with 4°C. The soluble protein content, expressed as a percentage of the total protein, increased by 1.5% (P = 0.032) for Sunco and by 8.0 % (P = 0.158) for Sunsoft during storage at 30°C compared with those samples stored at 4°C. Analysis by SDS‐PAGE and subsequent protein identification revealed that the most evident change that occurred during storage at 30°C was an increase in the content of high molecular weight glutenin subunits (HMW‐GS) in the soluble fraction. The potential effect of changes in solubility of HMW‐GS on functional properties is discussed.     

Germinability of <Emphasis Type="Italic">Vicia sativa</Emphasis> L. seeds After 10 Years of Storage in a Base Collection

The germinability of the Vicia sativa L. seed samples in the base collection at the Centro de Recursos Fitogenéticos (Spain) was controlled in 1986 and 1996. The mean germination of the collection, assessed by One-Sample T Test, was higher than 85%, suggesting its viability was properly maintained along the period. However, changes in germination along the same period assessed by Paired-Samples T Test showed a slight decrease in its global germinability. More data on the viability of stored seeds worldwide – including communication of unpublished data – are needed. Viability assays should be performed according to standard, internationally coordinated protocols and statistical analysis, within an adequate documentation system that assures the integrity of accession information.     

RAPD and ISSR molecular markers in <Emphasis Type="Italic">Olea europaea</Emphasis> L.: Genetic variability and molecular cultivar identification

Thirty Portuguese and eight foreign olive (Olea europaea L.) cultivars were screened using Random Amplified Polymorphic DNA (RAPD) and Inter-Simple Sequence Repeat (ISSR) markers. Twenty RAPD primers amplified 301 reproducible bands of which 262 were polymorphic; and 17 ISSR primers amplified 204 bands of which 180 were polymorphic. The percentage of polymorphic bands detected by ISSR and RAPD was similar (88 and 87%, respectively). The genetic variability observed was similar in the Portuguese and foreign olive cultivars. Seven ISSR and 12 RAPD primers were able to distinguish individually all 38 olive cultivars. Twenty specific molecular markers are now available to be converted into Sequence Characterised Amplified Region (SCAR) markers. Relationships among Portuguese and foreign cultivars is discussed.     

Effect of Storage on Fat Acidity and Pasting Characteristics of Wheat Flour

Two cultivars of wheat (Triticum aestivum L.), Sunco and Sunsoft, were used to study the influence of storage time and temperature on the formation of starch-lipid complexes in flour pastes. Untreated and fat-reduced whole meal flours were stored separately for up to 12 months at 4, 20, and 30°C. The stored samples were analyzed for fat acidity, pasting properties, and iodine binding values. Fat acidity increased significantly in the untreated flour samples stored at 30 and 20°C compared with 4°C. Starch pasting properties, as measured using a Rapid Visco Analyser (RVA) indicated that the final viscosity of untreated flour samples of both cultivars increased significantly with storage time and elevated temperature, and correlated positively with increased fat acidity. Iodine binding values of the RVA pastes decreased with storage time and elevated temperature, and correlated negatively with fat acidity and final viscosity. The fat-reduced Sunco and Sunsoft flours showed less pronounced changes compared with untreated flours, whereas small changes in the RVA parameters were noted in grains stored over 12 months. The results indicate that free fatty acids are released during storage and that they increase the potential for starch-lipid complex formation when stored whole meal wheat flours are pasted in the RVA. These changes were evident after two to three months of storage at 20 and 30°C.     

Effects of Rough Rice Storage Conditions on Gelatinization and Retrogradation Properties of Rice Flours

Changes in gelatinization and retrogradation properties of two rice cultivars, Bengal and Kaybonnet, during rough rice storage were studied using differential scanning calorimetry (DSC). The storage variables included two storage moisture contents (12 and 14%), three storage temperatures (4, 21, and 38°C), and four storage durations (0, 3, 9, and 16 weeks). Rough rice cultivar, storage temperature, moisture content, and duration affected (P < 0.05) the enthalpies and temperatures of gelatinization and retrogradation of rice flour. Bengal had a higher gelatinization enthalpy (P < 0.005) but lower gelatinization temperatures (P < 0.0001) than the long-grain Kaybonnet. Rice stored at 38°C exhibited higher gelatinization enthalpy and temperatures (P < 0.05) than those stored at 4 or 21°C. Storage duration affected the gelatinization and retrogradation properties through a higher order, rather than a linear, relationship.     

Molecular characterization of genetic diversity,structure, and differentiation in the olive (<Emphasis Type="Italic">Olea europaea</Emphasis> L.) germplasm collection of the United States Department of Agriculture

Fifteen microsatellite loci were used to genotype 108 accessions of cultivated olive, Olea europaea L. ssp. europaea var. europaea, and eight of O. europaea L. ssp. cuspidata (Wall. ex G. Don) Ciferri, from the germplasm collection of the United States Department of Agriculture in Davis, California. Number of alleles per locus ranged from 3, for locus IAS-pOe12_A, to 16, for locus ssrOeUA-DCA11, with an overall mean of 9.93. Observed heterozygosity ranged from 0.175, for locus UDO99–019, to 0.937, for locus GAPU89, with a mean of 0.640. The cluster analysis using the Unweighted Pair Group Method using Arithmetic mean (UPGMA) method displayed thirteen clusters within seven main groups that can be partially described by common geographic origin or fruit use, though overlap among these groups was common. The locus-wise total gene diversity (H _T) ranged from 0.319, at UDO99–019, to 0.847, at ssrOeUA-DCA3, with an overall mean of 0.696. Most of the gene diversity was partitioned within clusters, with proportions (H _S/H _T) ranging from 0.633, at IAS-pOe12_B, to 0.848 at GAPU89 per locus, with a mean of 0.759. The principal components analysis explained 24.8% of the total variation along the first two components. Projection of accessions onto the first two principal components produced affinities generally in agreement with the results of the UPGMA cluster analysis. The California cultivar ‘Mission’ clustered closely with Iberian cultivars and may represent clonal selections adapted to local growing conditions. The results show significant diversity but low levels of differentiation among olive cultivars within the collection.     

Influence of drying vs. freezing of archived soil samples on soil organic matter fractions

Archived soil samples are a valuable tool for any long‐term soil research. We analysed total carbon (C) and nitrogen (N) content and soil organic matter fractions in 38 archived soil samples that were stored for up to 21 years and compared air‐dried storage to frozen storage conditions. Samples include top‐ and upper subsoils, different soil texture and land use with C contents between 4.3 and 174 mg g^?1. The results from this study reveal no changes in total C and N contents with storage time up to 21 years or type of storage (freezing vs. air drying). The analyses of soil physical fractions also revealed no significant differences between air‐dried stored and frozen stored samples for most samples. However, we found indications, that freezing of soil material might lead to changes in the mineral fractions for soils containing high amounts of water. Therefore, and as archiving soils in a frozen state is more expensive than storing air‐dried samples, we recommend the use of air‐dried samples for C quality analyses of archived soil samples.     

Effects of Prolonged Storage at Freezing Temperatures on Starch and Baking Quality of Frozen Doughs

The effects of prolonged frozen storage on the starch, rheological, and baking properties of doughs were investigated. Four hard red spring (HRS) wheat cultivars exhibiting consistently different gluten characteristics were used. Gelatinization properties of starches isolated from fresh and thawed frozen doughs over 16 weeks of frozen storage were examined using differential scanning calorimetry (DSC). Significance of results varied with cultivar, but all cultivars showed a significant increase in ΔH with increased frozen storage time, indicating water migration and ice crystallization. The amount of freezable water in frozen doughs increased for all cultivars with frozen storage, but the rate of increase varied. Glupro showed a consistent increase in freezable water during frozen storage (41.6%), which may be associated with its high protein content and strong gluten characteristics. Rheological strength of the frozen doughs which was determined by decreases in extensigraph resistance and storage modulus (G′), declined throughout frozen dough storage. Proofing time increased from 45 min for fresh doughs to an average of 342 min for frozen doughs stored 16 weeks. Concomitantly, loaf volumes decreased from an average of 912 cm³ for fresh doughs to an average of 738 cm³ for the frozen doughs. Longer proof times and greater loaf volume loss were obtained for the cultivars exhibiting greater gluten strength characteristics.     

Effect of Storage Temperature for Paddy on Consumer Perception of Cooked Rice

Effect of storage temperature (ST) (5, 15, and 25°C) for paddy on the consumer perception of cooked rice (CR) was investigated with six major rice cultivars in Korea (Ilmibyeo, Chucheongbyeo, Ilpumbyeo, Hwayeongbyeo, Nampyeongbyeo, and Odaebyeo) after 12 months of storage. Germination rate (GR) of the paddy, grading characteristics (percentages of head rice, broken kernels, damaged kernels, colored kernels and chalky kernels) of milled rice (MR) kernels, texture profile analysis (hardness, springiness, cohesiveness, adhesiveness, and chewiness) and color (L*, a*, and b*) of CR were measured. Also, consumer testing on CR was done with 108 consumers. Consumers evaluated acceptability for odor, appearance, taste, texture, and overall purchase intent, and willingness to pay (WTP) of CR. After 12 months of storage, physicochemical characteristics of MR and CR were significantly different depending on ST. The significant difference among three ST of paddy was noted for GR, color b* value, fat acidity of MR, and overall consumer acceptability of CR. The GR was constant during 12 months of storage at 5°C, whereas a significant decrease of GR was noted for all six cultivars within 12 months of storage at 25°C. The average WTP for rice stored at 5°C for 12 months was $U.S. 45.68/20 kg, whereas WTP for rice stored at 15°C and 25°C were $U.S. 44.19/20 kg and $U.S. 41.87/20 kg, respectively, implying the importance of ST on grain quality and product value by consumers. Overall consumer acceptability had high correlation coefficient with WTP (r = 0.985). Overall consumer acceptability had highest correlation with GR of paddy (r = 0.861), followed by b* value of CR (r = –0.826), fat acidity (r = –0.768), cohesiveness (r = 0.733), and hardness (r = –0.650) of CR by TA, implying GR of paddy and b* value of CR could be used as indicators for eating quality of rice.     

Mathematical Modeling of Odor Deterioration of Millet (Pennisetum glaucum) Dough (fura) as Affected by Time‐Temperature and Product Packaging Parameters

Consumer panelists evaluated the influence of temperature (5, 25, 35°C), storage time, and packaging material (aluminum foil or low‐density polyethylene [LDPE]) on the sensory quality of millet dough (fura). The quality attributes of interest were mold growth, color, odor, and moisture. The odor sensory attribute changed significantly (P < 0.05) during storage and was influenced by storage time and temperature. Interactive effect of packaging‐temperature and temperature‐time affected odor changes significantly. A kinetic reaction model was used to analyze odor sensory data. The degradation of pleasant odor followed a first‐order reaction, and the temperature dependence of these reactions indicated an Arrhenius relationship. While an activation energy (E_A) of 29.98 kJ/mol was calculated for samples stored in aluminum foil, a higher value of 49.04 kJ/mol was obtained for samples stored in LDPE. The negative values of enthalpy (ΔH*) in both packages indicate that deterioration change in fura is exothermic. The higher values of E_A and free energy of activation (ΔG*) for fura stored in LDPE packages indicate a large change in quality. However, the lower values of free energy of activation (ΔG*) and negative values of entropy of activation (ΔS*) for fura stored in aluminum foil packages indicate a product that is more thermally stable, and odor deterioration is less influenced by temperature. There is no significant difference (P > 0.05) in the shelf life of fura stored at 20, 25, and 35°C in the two packaging materials. However, there were significant differences in shelf life of fura stored at 5°C.     

Changes in Retrogradation Properties of Rice Starches with Amylose Content and Molecular Properties

The increases in storage modulus (G′), retrogradation enthalpy change (ΔH) and ΔH‐related Avrami kinetic parameters of gelatinized rice starch dispersions at 25% (w/w) were investigated with respect to storage period, amylose content (AC), and molecular properties. Three high‐AC and five low‐AC rice cultivars were compared for understanding the multiple influences of AC and molecular properties involved. After refining the results of correlation analysis, the G′ of just‐cooled samples changed positively, mainly with AC and additionally with the average chain length of amylose (CL_AM) and the weight ratio of extra‐long plus long chains to short chains of amylopectin (AP) (r_APchain). The developed ΔH on short‐term storage (10 days) elevated with increasing AC and CL_AM and decreasing degree of polymerization of AP (DP_AP), but after long‐term aging for one to three months with increasing r_APchain, especially for the low‐AC cultivars examined. Greater Avrami rate constants for retrogradation could be attributed to the combination of a lower DP_AP and r_APchain or AP chain length and a greater CL_AM. The polynomials using these critical factors to describe the retrogradation parameters were elucidated and could account for 85–99.6% of data deviations.     

ISSR Variation in Olive-tree Cultivars from Morocco and other Western Countries of the Mediterranean Basin

In olive tree (Olea europaea L.), 12 varieties (or cultivars) representing the main domesticated material used in Morocco and 19 olive cultivars used extensively in five countries of the western Mediterranean Basin, were analysed using inter-simple sequences repeat (ISSR) markers which had never been used previously for extensive discrimination of cultivars. Four selected primers produced a total of 26 polymorphic reproducible amplification fragments. Combinations of these ISSR markers allowed to identify 25 of the 31 cultivars. Two additional combinations were distinguished, each corresponding to three Moroccan cultivars or local varieties. Evidence of a multiclonal composition in the widely cultivated variety ‘Picholine marocaine’ was obtained by the identification of three genotypes within the four morphologically distinct clones analysed in the variety. In the UPGMA phenogram based on the proportion of shared ISSR fragments, five groups of cultivars were distinguished at the 40% critical value of similarity. Four of the groups contained varieties from various geographic origins, as the consequence of successive human migrations which favoured olive dispersion throughout the Mediterranean Basin. However, the fifth group gathered together 9 of the 12 Moroccan cultivars and very few cultivated clones from Greece and Spain. The results suggest that most of the Moroccan cultivars are closely related and likely originated from local domestication.     

Variation in seed longevity of rice cultivars belonging to different isozyme groups

The storage potential of seeds harvested at different stages of maturity was studied in ten cultivars of Oryza sativa, representing six known isozyme groups, and in two cultivars of O. glaberrima. Mass maturity (the end of the seed-filling period) was attained between 14.2 and 20.2 days after anthesis (DAA). A comparison of the estimates of p ₅₀ (time in storage for viability to decline to 50%) of seeds harvested at 21, 28 and 35 DAA and stored at 35°C with 15% moisture content showed that maximum longevity was attained between 28 and 35 DAA in most cultivars. Cultivars belonging to isozyme group II survived longer than other cultivars with estimates of p ₅₀ nearly doubled. On the other hand, the floating rices of Group IV had shorter longevity. Within group VI, the upland cultivar survived longer than the lowland cultivar. Both O. glaberrima cultivars survived reasonably well, showing that African rice cultivars also differ in longevity.     

Effects of olive fruit quality and oil storage practices on the diacylglycerol content of virgin olive oils

The evolution of 1,3- and 1,2-isomers of diacylglycerols (DGs) in olive oils obtained from healthy olives and the influence of the olive quality was studied. Healthy olive fruits yielded oils containing almost exclusively 1,2-isomers whereas altered olives produced oils with significant amounts of 1,3-isomers. Virgin olive oils obtained from various olive cultivars and stored at different temperatures showed triacylglycerol hydrolysis and diacylglycerol isomerization depending on the acidity and temperature. The results indicated that the relationship between acidity and total diacylglycerol content has scarce utility for detecting mild refined oil in virgin olive oil. On the other hand, the 1,3-/1,2-DG isomers ratio is useful for assessing the genuineness of virgin olive oils with low acidities during the early stages of storage.     

Functional Properties of Commingled Rice‐Cultivar Lots

Commingling of rice cultivars commonly occurs during harvest, drying, and storage operations. Because different cultivars often have different functional properties, there is a need to study the impact of commingling on these properties. Two long‐grain hybrid (H) cultivars, CL XL745 and CL XL729, and two long‐grain pureline (P) cultivars, CL 151 and Wells, were used to prepare H/P, H/H, and P/P commingles in various proportions. Gelatinization and pasting properties of all individual lots and commingled samples were measured. When two cultivar lots with different onset gelatinization temperatures (T_os) were commingled, the T_o of the commingled sample was similar to the T_o of that cultivar in the commingle with the lower T_o. T_ps, T_cs, and ΔHs of commingled samples generally increased or decreased according to the mass percentages of the cultivars in the samples. Peak, breakdown, and final viscosities of commingled samples also varied according to the mass percentages of the cultivars in the commingled samples. These findings are intended to help make decisions regarding cultivar commingling and to optimize process conditions and product characteristics, given the gelatinization and pasting properties of individual‐cultivar lots.     

Second meiotic division restitution (SDR) 2n pollen formation in diploid and hexaploid species of Asparagus

Summary Plants of two cultivars of 2x A. officinalis L. and two related ornamental species, 2x A. plumosus Baker and 6x A. densiflorus (Kunth) Jessop cv. Sprengeri were screened for production of pollen of heterogeneous size. Twenty four plants out of thirty-one studied produced this type of pollen, with frequencies of 3% or more large pollen. Some of these plants also produced giant grains. The numerically unreduced pollen arose by the lack of chromosome migration at Anaphase II in either one or both cells of a meiocyte, followed by the absence of cytokinesis in cells with abnormal chromosome behavior, a Second Meiotic Division Restitution (SDR) cytological mechanism. Double unreduced pollen resulted from a similar mechanism acting at both Anaphase I and Anaphase II stages. The high frequency of plants which produced 2n pollen in significant amounts is taken as an indication that the modified meiosis observed is under genetic control.     

Infrared Drying Characteristics of Long‐Grain Hybrid,Long‐Grain Pureline,and Medium‐Grain Rice Cultivars

The objective for this study was to investigate the effectiveness of scaled‐up infrared (IR) heating followed by tempering steps to dry freshly harvested rough rice. An industrial‐type, pilot‐scale, IR heating system designed to dry rough rice was used in this study. The heating zone of the equipment had catalytic IR emitters that provided heat energy to the sample as it was conveyed on a vibrating belt. The sample comprised freshly harvested rough rice of long‐grain pureline (Cheniere), long‐grain hybrid (6XP 756), and medium‐grain (CL 271) cultivars at initial moisture contents of 23, 23.5, and 24% wb, respectively. Samples at a loading rate of 1.61 kg/m² were heated with IR of radiation intensity 5.55 kW/m² for 30, 50, 90, and 180 s followed by tempering at 60°C for 4 h, at a product‐to‐emitter‐gap size of 450 mm, in one‐ and two‐pass drying operations. Control samples were gently natural air dried in an equilibrium moisture content chamber set at relative humidity of 65% and temperature of 26°C to moisture content of 12.5% wb. The effects of IR treatments followed by tempering on percentage points of moisture removed, head rice yield, energy use, rice color, and pasting characteristics were evaluated. For all cultivars, percentage point moisture removed increased with increase in IR drying duration. For all rice cultivars, one‐pass IR treatments for 180 s resulted in head rice yield significantly lower than that of rice dried with natural air in the controlled‐environment conditions (P < 0.05). Energy required to dry rice increased with increase in drying duration. Viscosity values of all the experimental samples were significantly greater (P value < 0.05) than that of the control samples for all the cultivars, except those treated with IR for 180 s. There was a significant difference (P < 0.05) in the color index (ΔE ) of treated milled samples and the controls. In conclusion, the study provided information crucial to understanding the effects of scaled‐up radiant heating and tempering of rough rice on drying rates and rice quality for long‐grain pureline, long‐grain hybrid, and medium‐grain rice cultivars.