Low Moisture Percentages Research Articles

Effects of Enhancement Techniques on Physical And Chemical Properties of Beef Flanks

ObjectivesEnhancement of beef with non-meat ingredients is a common practice to improve both palatability and chemical characteristics. However, the delivery method of brine solutions has not been well studied and could play a role in the activity of certain ingredients, ultimately influencing meat characteristics. This study was designed to determine if different enhancement methods impacted the overall physical and chemical properties, including pH, percent pick-up, slice shear force (SSF), and cooked moisture content, of enhanced (water, salt and sodium tripolyphosphate) rectus abdominus.Materials and MethodsUSDA Select beef flank steaks (rectus abdominus) were procured from a beef abattoir and processed at 10 d postmortem. Steaks (n = 100; 20/treatment) were denuded and assigned randomly to one of the five treatments: untreated control (CNT), vacuum tumbled without marinade (TCNT), vacuum tumbled with marinade (TUMB), needle injected with marinade (INJ), and injected with marinade plus vacuum tumbled (IPT). Initial weight and pH were collected pre-enhancement for TUMB, INJ, and IPT. Samples were weighed again immediately after enhancement and 20 min after enhancement. Three weights were collected for IPT: pre-enhancement, post-injection and post-tumble. After flank enhancement, they were sliced in half parallel to the muscle fiber. One half was designated for laboratory analysis. The halves were then frozen and thawed 24 h prior to cooking. A 50-g raw sample was obtained from each flank prior to cooking for SSF to analyze raw moisture content. Each flank was cooked to an internal temperature of 72°C and allowed to rest for 3 min prior to slicing for SSF.ResultsTreatment influenced final pH (P < 0.01), with final pH increasing in INJ, TUMB, and IPT. Differences were noted in final pH between treatments; INJ had the highest pH (6.15), followed by IPT (6.06), TUMB (5.83), CNT (5.76), and TCNT (5.71), with a difference observed between each treatment (P < 0.05). Treatment also impacted (P < 0.01) SSF. The addition of marinade through injection and tumbling reduced (P < 0.05) SSF values, as CNT and TCNT had greater SSF values compared to all other treatments. Injection further reduced SSF values, as INJ and IPT had lower SSF values compared to TUMB (P < 0.05). Cooked moisture was also influenced (P < 0.01) by treatment. IPT and TUMB had greater moisture percentage compared to all other treatments; INJ was intermediate, and CNT and TCNT similarly had lower moisture percentage than the remaining treatments (P < 0.05). Of the three treatments that involved marination, initial and final percent pick-up and drip loss were all influenced by treatment (P < 0.01). Initially, INJ (14.5%) had the greatest percent pick-up, IPT was intermediate (12.9%), and TUMB had the lowest percentage (11.8%). However, drip loss was greatest for INJ (2.3%), intermediate for TUMB (0.2%), and lowest for IPT (0.0%). Final percent pick-up was now greatest for IPT (12.9%), intermediate for INJ (11.9%), and lowest for TUMB (11.5%).ConclusionEnhancement methods can influence physical and chemical traits in terms of moisture, SSF and pH. Injection influenced shear force more than tumbling, whereas tumbling had greater effects on moisture than injection. Combining injection with tumbling had the most positive effect on shear force as well as moisture retention.

Creep behaviour of steel bonded joints under hygrothermal conditions

The aim of this research is to study the influence of moisture absorption at low moisture contents on the creep behaviour of an epoxy adhesive in steel bonded joints. Single lap joints were manufactured using high strength steel adherends and a two-component epoxy adhesive. The single lap joints were tested at load levels corresponding to average lap shear stresses of ± 5%, 15%, 30% and 45% of the dry lap shear strength in both 40 °C air and 40 °C distilled water. Specimens were not pre-aged to be able to analyse the coupled effect of moisture and loading. The test results show that an increase in the load level resulted in an increase in the instantaneous strain and in the creep strain rate. The creep strain of single lap joints loaded in water was generally larger than for the ones loaded in air. For joints loaded in water the creep behaviour was found to be dependent on the moisture concentration in the adhesive. At low moisture percentages creep was suppressed, resulting in a lower instantaneous strain. At higher moisture percentages creep was promoted, resulting in a larger strain rate. The suppression of creep at low moisture percentages is attributed to water molecules bonding to the epoxy macromolecules, resulting in a reduction in molecular mobility and a smaller creep strain. At higher moisture percentages the plasticizing effect of the water dominates, resulting in a larger creep strain. The Maxwell three-element solid model and Kelvin-Voigt three-element solid model were used to simulate the creep behaviour of the single lap joints loaded in air and water. The models gave good representations of the creep response across the different load levels in both water and air, they were however unable to give a correct representation of the instantaneous strain of the single lap joints loaded in water. This is attributed to the models being unable to account for the present short-term relaxation process that is dependent on the moisture concentration.

Effects of Enhancement Techniques on Physical And Chemical Properties of Beef Flanks

ObjectivesEnhancement of beef with non-meat ingredients is a common practice to improve both palatability and chemical characteristics. However, the delivery method of brine solutions has not been well studied and could play a role in the activity of certain ingredients, ultimately influencing meat characteristics. This study was designed to determine if different enhancement methods impacted the overall physical and chemical properties, including pH, percent pick-up, slice shear force (SSF), and cooked moisture content, of enhanced (water, salt and sodium tripolyphosphate) rectus abdominus.Materials and MethodsUSDA Select beef flank steaks (rectus abdominus) were procured from a beef abattoir and processed at 10 d postmortem. Steaks (n = 100; 20/treatment) were denuded and assigned randomly to one of the five treatments: untreated control (CNT), vacuum tumbled without marinade (TCNT), vacuum tumbled with marinade (TUMB), needle injected with marinade (INJ), and injected with marinade plus vacuum tumbled (IPT). Initial weight and pH were collected pre-enhancement for TUMB, INJ, and IPT. Samples were weighed again immediately after enhancement and 20 min after enhancement. Three weights were collected for IPT: pre-enhancement, post-injection and post-tumble. After flank enhancement, they were sliced in half parallel to the muscle fiber. One half was designated for laboratory analysis. The halves were then frozen and thawed 24 h prior to cooking. A 50-g raw sample was obtained from each flank prior to cooking for SSF to analyze raw moisture content. Each flank was cooked to an internal temperature of 72°C and allowed to rest for 3 min prior to slicing for SSF.ResultsTreatment influenced final pH (P < 0.01), with final pH increasing in INJ, TUMB, and IPT. Differences were noted in final pH between treatments; INJ had the highest pH (6.15), followed by IPT (6.06), TUMB (5.83), CNT (5.76), and TCNT (5.71), with a difference observed between each treatment (P < 0.05). Treatment also impacted (P < 0.01) SSF. The addition of marinade through injection and tumbling reduced (P < 0.05) SSF values, as CNT and TCNT had greater SSF values compared to all other treatments. Injection further reduced SSF values, as INJ and IPT had lower SSF values compared to TUMB (P < 0.05). Cooked moisture was also influenced (P < 0.01) by treatment. IPT and TUMB had greater moisture percentage compared to all other treatments; INJ was intermediate, and CNT and TCNT similarly had lower moisture percentage than the remaining treatments (P < 0.05). Of the three treatments that involved marination, initial and final percent pick-up and drip loss were all influenced by treatment (P < 0.01). Initially, INJ (14.5%) had the greatest percent pick-up, IPT was intermediate (12.9%), and TUMB had the lowest percentage (11.8%). However, drip loss was greatest for INJ (2.3%), intermediate for TUMB (0.2%), and lowest for IPT (0.0%). Final percent pick-up was now greatest for IPT (12.9%), intermediate for INJ (11.9%), and lowest for TUMB (11.5%).ConclusionEnhancement methods can influence physical and chemical traits in terms of moisture, SSF and pH. Injection influenced shear force more than tumbling, whereas tumbling had greater effects on moisture than injection. Combining injection with tumbling had the most positive effect on shear force as well as moisture retention.

Hoof Quality of Anglo-Arabian and Haflinger Horses.

IntroductionFoot quality is essential to the horse’s movement. The barefoot approach favours the animal’s welfare. Environment and selection determine hoof characteristics.Material and MethodsHoof characteristics of eight Anglo-Arabian (AA) and nine Haflinger (HA) horses were studied. After a preliminary visual analysis of feet, nail samples were collected after trimming for physico-chemical analysis. The parameters were submitted to analysis of variance. A principal component analysis and a Pearson correlation were used to compare mineral contents.ResultsThe hooves of both breeds were healthy and solid. The hooves of HA horses were longer than those of AA horses (14.90 ±0.30 cm vs 13.10 ±0.60 cm), while the AA hoof was harder than the HA hoof both in the wall (74.55 ±2.95 H vs 60.18 ±2.67 H) and sole (67.00 ±5.87 H vs 43.0 ±4.76 H). In comparison with the sole, the AA hoof wall also had a lower moisture percentage (12.56 ±0.67% vs 20.64 ±0.76%), while crude protein and ash contents were similar in both regions. The AA hoof showed a higher Se content, while the HA hoof had a higher level of macroelements. The negative correlations of K with Cu, Fe, Ni, Pb, and Zn in the AA hoof may indicate osmoregulation activity.ConclusionThe hoof morphology of AA and HA horses met the literature parameters for mesomorphic horses. Both breeds had healthy and well-conformed hooves, useful for sport and recreation activities.

Effect of a Superabsorbent for the Improvement of Car Seat Thermal Comfort

The use of super absorbent polymers (SAP) for moisture absorption and comfort is still unexplored. The aim of this work was to observe the application of super absorbent fibres in car seats for comfort purposes. In this research the efficiency of different SAP fibrous webs were determined under different moisture percentages to examine the sorption and desorption efficiency. A SAP fibrous web with low thickness and high moisture absorption were tested with a multilayer sandwich structure of a car seat cover to determine moisture absorption through the cover material. The standard Cup method was used to determine the moisture permeability of different car seat covers with a superabsorbent layer closed with impermeable polyurethane foam. It was observed that the SAP fibrous layers are very effective in absorbing and desorbing water vapour under extremely high and low moisture percentages. In extreme humid conditions (95%RH), 20g of the SAP layer absorbs nearly 70% of its weight in water vapour, reaching the maximum absorption capacity in 6 hours.

Estimation and Comparison of Carbon Sequestration byZygophyllum atriplicoidesandGymnocarpus decander

This study was conducted to evaluate the effect of plant organs (root, stem, and leaf) of two plants,Zygophyllum atriplicoidesandGymnocarpus decander, on carbon sequestration and some soil characteristics in the Saleh–Abad region, 41 km north of Haji–Abad, Bandar–Abbas, in 2012. This study was carried out by two separate factorial experiments. The first factor was the type of plant species in both experiments. The second factor was the plant organs in experiment I and different soil depths in experiment II. The results showed that the soil withZ.atriplicoideshad a higher soil saturation percentage, moisture percentage, nitrogen percentage, and organic carbon percentage; the soil withG. decanderhad a higher electrical conductivity. Soil at 0–15 cm depth had a higher electrical conductivity, nitrogen percentage and organic carbon, as well as a lower moisture percentage, compared with 15–30 cm depth, which was similar for both plants. Soil withZ. atriplicoidesand at a 0–15 cm depth had higher clay and silt percentages, and a lower sand percentage. Multiple regression showed that nitrogen and moisture percentage were the most effective traits contributing to carbon sequestration. Furthermore,Z.atriplicoides, compared toG. decander, had the higher stored organic carbon level in tissues; stems and leaves had higher and lower levels of stored organic carbon, respectively, in both plants. Overall, the results of this study indicated that the highest carbon sequestration was obtained in soils withZ. atriplicoidesat 0–15 cm depth.

Comparison of portuguese soils from different geographical regions using physicochemical, biological and biochemical parameters

As a way of getting a comprehensive assessment of soil quality it is necessary to gather information on several appropriate soil parameters as well as also to perceive their spatial variation between geographic regions. The present work aimed to characterize and compare soil samples from different geographical regions and vegetation covers in the Portuguese territory through the use of physicochemical, biological and biochemical parameters. The study also intended to ascertain if those parameters are sensitive tools that consistently respond to geographical variations. Physical and chemical (soil organic matter contents, moisture, pH and conductivity), biological (macroarthropod es and diversity) and biochemical (potential nitrification, dehydrogenase and acid phosphatase activities) soil parameters were determined for three different regions of Portugal. Several sub-areas were chosen within each region, in order to include main vegetation patches. At each sampling sub-area, 5 traps were randomly set up for the collection of macroarthropods. For each sampling location, diversity descriptors of soil macrofauna were calculated: species richness, β diversity, the Shannon diversity (H′) and Pielou evenness (J′) indices. A principal component analysis (PCA) was used to plot the different sampling locations based on physical and chemical parameters; a canonical correspondence analysis (CCA) was performed to analyse the relationships between soil fauna and environmental variables (physicochemical parameters and enzyme activities) and a partial canonical correspondence analysis (pCCA), with vegetation patches as covariables, was carried out to perceive their contribution to the variation in macroarthropod distribution. Physical and chemical parameters discriminated soils from the different geographic regions in the PCA. Nevertheless, a CCA of environmental variables (physical and chemical properties, dehydrogenase activity, acid phosphatase activity and potential nitrification) and soil macroarthropod catches only discriminated continental soils (Arouca and S. Domingos Mine) from insular ones (Porto Santo Island). The former were correlated with high dehydrogenase activity (DHA) and potential nitrification values, while soils from the Porto Santo Island were particularly correlated with high pH values and low moisture percentages. However, in spite of the extreme conditions, Porto Santo sampling sub-areas presented a great diversity of macroarthropods, especially when compared to the S. Domingos Mine. The pCCA showed that the different vegetation patches only explained 15% of the variation in edaphic species distribution. Even though physical and chemical parameters were sufficient to discriminate the different geographical regions included in this study, biochemical and biological parameters grouped continental regions, discriminating them from the insular one. According to the CCA triplot, it was evident that the sampling sub-areas from the island were negatively correlated with soil moisture, suggesting that this was probably the main factor for the suppression of the microbial parameters in the island. On the other hand, the location of the S. Domingos mine area, in a metallogenetic province — the Iberian Pyrite Belt — may have contributed to the dominance of taxa more adapted to higher background levels of heavy metals. In order to perceive geographical variation among different regions, more information is needed regarding different vegetation covers and the chemical composition of their corresponding litter, as well as about other soil chemical parameters. The data gathered in this study will help to distinguish variation in soil biological and biochemical parameters induced by abiotic conditions from the one promoted by anthropogenic disturbances.

Effect of Feeding Ammoniated Wheat Straw Treated with and without Hydrochloric Acid on Meat Quality and Various Sensory Attributes of Growing Male Buffalo (Bubalus bubalis) Calves

An experiment was conducted to study the effect of feeding ammoniated wheat straw treated with and without HCl on meat quality and various sensory attributes of growing male buffalo (Bubalus bubalis) calves. Due to urea-ammoniation, the CP content of wheat straw increased from 2.90 to 6.96%. The addition of HCl along with urea during urea-ammoniation further increased the CP content to 10.09%. The proximate composition (% fresh basis) of psoas major, longissimus dorsi and semitendinosus were comparable among the groups. However, comparatively higher cumulative muscle mean protein and ash percentage and lower moisture percentage in groups II and III in comparison to group I indicated the desirable effect of feeding AWS and HCl-AWS. The cumulative muscle mean pH in group III (5.54) was comparatively lower than group I (5.65) and II (5.62). The cumulative group mean pH and water holding capacity (% water retained) in semitendinosus was comparatively lower than psoas major and longissimus dorsi. The cumulative muscle mean SSP (g%) was significantly (p<0.05) lower in group III (41.78) than group I (42.45). The cumulative group mean cooking loss (%) was significantly (p<0.01) lower in psoas major (31.61) and longissimus dorsi (29.78) than semitendinosos (35.10). The cumulative group mean SFV (kg/cm 2 ) of psoas major, longissimus dorsi and semitendinosus were 6.38, 6.32 and 6.56, respectively, being lowest in psoas major and highest in semitendinosus. However, the cumulative muscle mean SFV (kg/cm 2 ) in group I, II and III were 6.53, 6.56 and 6.17, respectively, being lowest in group III and highest in group II. The scores of the cooked (2% common salt) buffen for various sensory attributes viz. appearance, flavour, juiciness, texture, mouth coating and overall palatability were comparable among the groups. Results suggested that feeding of ammoniated wheat straw treated with and without HCl to growing male buffalo calves for 180 days had no adverse effect on the meat quality and various sensory attributes.

Carcass traits, muscle characteristics, and palatability attributes of lambs expressing the callipyge phenotype

Dorset×Suffolk crossbred wethers expressing a normal phenotype (normal, n=10) and callipyge phenotype (CLPG, n=9) were fed individually and slaughtered upon reaching maximum growth potential. Carcass weight did not differ ( P>0.05), but fat thickness was lower (0.30 vs. 0.56 cm), ribeye area was greater (24.4 vs. 16.6 cm 2), and USDA yield grade was improved (1.6 vs. 2.6) for CLPG carcasses ( P < 0.05). Carcasses from CLPG demonstrated higher cutability and a more desirable muscle to bone ratio, with less fat and more lean as a percentage of total side weight ( P<0.05). Biceps femoris (BF), semitendinosus (ST), semimembranosus (SM), longissimus thoracis et lumborum (LTL), and triceps brachii (TB) were used to compare muscle characteristics of both phenotypes. Muscle from normal lambs had lower calpastatin activity, higher fat percentages and lower moisture percentages ( P<0.05). Total amount and solubility of collagen were not affected by phenotype nor was sarcomere length. Shear force and trained sensory attributes were evaluated for BF and LTL only. Shear force values did not differ between normal and CLPG BF while CLPG LTL had higher ( P< 0.05) shear force values than normal LTL. Biceps femoris did not differ between phenotypes in trained sensory panel ratings. However, CLPG LTL received the lowest sensory ratings for connective tissue amount and myofibrillar and overall tenderness (6.11, 4.97, and 4.95, respectively) and the normal LTL received the highest ratings ( P < 0.05; 7.10, 7.00, and 6.90, respectively). The CLPG phenotype had a positive influence on carcass characteristics but had a negative influence on tenderness of some muscles, possibly through the myofibrillar component of the muscle.

Effects of animal age, marbling score, calpastatin activity, subprimal cut, calcium injection, and degree of doneness on the palatability of steaks from limousin steers.

Strip loin (longissimus lumborum), sirloin (gluteus medius) and round (semimembranosus) subprimals from 114 purebred and crossbred Limousin steers were used to identify main effects and interactions of animal age, marbling score, calpastatin activity, subprimal cut, calcium injection (5% wt/wt with a 200 mM CaCl2 solution at 48 h postmortem), and degree of doneness on the palatability of cooked beef steaks. Steaks were aged for 14 d, frozen, thawed, cooked to different internal temperature end points, visually scored for degree of doneness, sheared on a Warner-Bratzler shear machine, and evaluated by a trained taste panel. Raw and cooked steaks from carcasses of higher USDA quality grades had higher fat and lower moisture percentages (P < .05). Higher degrees of doneness resulted in lower moisture percentages (P < .05). Lower shear force values were associated with less variation in shear force. Younger slaughter age and lower calpastatin activity both resulted in greater tenderness (P < .05). Shear force was lowest between "medium rare" and "medium" and increased toward both ends of the degree of doneness scale for round and sirloin steaks; however, shear force increased linearly with degree of doneness in strip loin steaks (P < .05). Subprimal cut had the largest effect on taste panel tenderness ratings, and degree of doneness had the largest effect on taste panel juiciness ratings. The improvement in shear force due to CaCl2 injection was greater for strip loin and sirloin steaks than for round steaks (P < .05 for the interaction). Injection with CaCl2 improved all taste panel attributes. In addition, CaCl2 injection reduced the toughening effects of cooking (P < .05).

Shelf-Life of Pasteurized Process Cheese Spreads Made from Cheddar Cheese Manufactured with a Nisin-Producing Starter Culture

Cheddar cheese made with a nisin-producing starter culture and Cheddar cheese made with a commercially available starter culture were used to manufacture pasteurized process cheese spreads at low and high moisture percentages (53 and 60%, respectively). Composition did not differ between spreads of similar moisture content with and without nisin. The nisin contents of cheese spreads were 301 and 387 IU/g at the high and low moisture percentages, respectively. Nisin was not inactivated by the thermal process used during cheese spread manufacture. Shelf-life of pasteurized process cheese spreads was determined during storage at 22 and 37°C. Low moisture cheese spreads with nisin had a longer shelf-life than corresponding cheese spreads without nisin when cheeses were incubated at either temperature. High moisture cheese spreads with nisin had a longer shelf-life than control spreads when cheeses were incubated at 22°C. However, shelf-life did not differ between high moisture spread with nisin and cheese spreads without nisin when cheeses were incubated at 37°C.

PROTEOLYSIS AND FERMENTATION OF GRAIN-CORN ENSILED AT SEVERAL MOISTURE LEVELS AND UNDER SEVERAL SIMULATED STORAGE METHODS

Proteolysis of ensiled grain corn (Zea mays L.) was studied in both whole-kernel and ground forms at initial grain moisture levels ranging from 22 to 36%. Three trials simulated and examined the effects of anaerobic fermentation, aerobic pre-ensiling and aerobic postensiling environments on soluble nitrogen (SN) formation (Trials 1, 2 and 3, respectively). Sealed mason jars (1.2 L) with fermentation locks, polyethylene-lined metal pails (23 L) and polyethylene-lined metal pails with fermentation locks were used as storage containers in Trials 1, 2 and 3, respectively. Soluble nitrogen as a percent of total nitrogen (TN) increased substantially during anaerobic fermentation (0–90 d), but increased only slightly and not at all during aerobic storage pre-ensiling (0–5 d) and postensiling (0–8 d). As moisture level increased, rates and extent of fermentation and proteolysis increased in both whole and ground grain (Trial 1). Soluble nitrogen contents after 90 d of sealed storage were approximately double for ensiled corn above compared to below 30% moisture. Grinding increased the rate but not the extent of proteolysis at grain moisture levels above 30%; grinding had little effect on SN formation or fermentation parameters at lower moisture percentages. A fourth trial compared the effect of three low-rate organic acid treatments to ground and sealed corn and an unsealed 1.5% (wt/wt) acetic:propionic acid (20:80) treatment on whole kernels for proteolysis in grain corn at 28% moisture. Only a 0.2% (wt/wt) acetic:propionic:formic acid:formaldehyde (10:40:20:30) treatment partially inhibited proteolysis; it did not control mold growth. A 1.5% acetic propionic acid treatment inhibited fermentation, but produced SN contents similar to the ensiled control. Key words: Proteolysis, corn, simulated, storage methods, moisture level

Effect of Tumbling and Tumbling Time on Quality and Microflora of Dry‐Cured Hams

ABSTRACTThirty‐two intact hams were utilized to study the effects of tumbling and tumbling time (1 hr continuous, 3 hr intermittent, 6 hr intermittent) on the quality and microflora of intact dry‐cured hams. Tumbled hams had higher salt concentrations, lower moisture percentages, and showed more muscle separation and excessive surface drying. Sensory panel scores were similar for all treatments except that 3 hr intermittently tumbled hams had higher salt and lower overall satisfaction scores. Tumbling significantly accelerated salt and nitrite penetration during the Fust 2 wk of curing but had little subsequent effect. Tumbled hams generally had lower microbial counts; however, after aging all hams were of acceptable microbial quality.

Vehicle Perturbation Effects upon a Tundra Soil‐Plant System: I. Effects on Morphological and Physical Environmental Properties of the Soils

AbstractChanges obtaining in the soil abiotic physical environment due to tracked‐vehicle disturbance were determined in Tundra soils near Barrow, Alaska. The study was a contribution of the U.S.I.B.P., Tundra Biome Program.Six years following the scarring of the tundra surface by several years of infrequent passage by tracked‐vehicles (Weasel), the soils within the track had higher bulk densities and temperatures, accelerated and deeper thaw, and lower moisture percentages than undisturbed soil. Soil morphology was little altered except for direct physical alteration of surface organic horizons and a slight increase in mottling of mineral horizons in all but the wetter portions of the track. The intensity of alteration and associated environmental changes were related to the degree of evident disturbance (the amount of visible damage to the vegetative cover and soil surface) which, in turn, were related to differences in the natural drainage of the soils along the tracks; disturbance being greater, the poorer the natural drainage.The study indicated that a slight amount of disturbance to the tundra surface may be beneficial in terms of increased productivity and nutrient content of vegetation (see Part II of this paper). On the other hand, heavy disturbance can result in severe damage to the tundra system due to subsidence and erosion preventing the revegetation of the disturbed areas.

Moisture and seed carbonization

In recent years the multidisciplinary approach of modem archeology has involved an increasing number of botanists in the recovery, identification, and interpretation of seeds from archeological excavations. These seeds are frequently carbonized. This is particularly true of tell archeology of the Middle East, where usually the concern is the origin and early development of agriculture. In many reports and discussions that treat this subject, the size of carbonized grains from various sites is used to support species or wild from cultivated form determinations. Also carbonized modem forms have been used as reference collections. Concern about relatively small size differences being given appreciable weight in such diagnosis has led to this study of the effect of moisture percentage at carbonization on the size of carbonized grain. Two lots of 10 seeds each of Triticum dicoccum Schrank., T. manococcum L., T. aestivum L., Hordeum vulgare L., and H. distichon L. were adjusted to 11 and 15 per cent moisture.2 Test seeds were carbonized by heating on an asbestos pad for ten minutes. This is thought to be a rough equivalent to grains accidentally dropped into an open fire by site occupants. It was apparent that the lower moisture percentage resulted in carbonized grains more representative of unaltered grain. Table I shows that in every case the length of the grain was shortened, but at 11 per cent moisture the grains were wider following carbonization whereas at 15 per cent they were narrowed. Although more tests with other moisture percentages and other methods of carbonization could

AN AUTO-IRRIGATOR FOR GROWING PLANTS IN THE LABORATORY

At present, the most practical method of controlling soil moisture for the roots of laboratory plants seems to be the method of adding water to the surface soil in order to bring the soil container, its soil, and the plants growing therein to a certain predetermined weight which represents the desired moisture content. The principal difficulty in this procedure lies in attaining the original distribution of moisture in the soil which was quite uniform at first, but soon afterward becomes variable both vertically and horizontally through the soil container. Hendrickson and Veihmeyer (2) found that uniform distribution of moisture in a soil container is unattainable after drying, until the water content again reaches the rather high level marked by the moisture equivalent. At low moisture contents, there are regions in the container with variable water content and the most active roots will be in the region of optimum moisture. The most successful mechanism for moisture control seems to be that devised by Livingston (3) and further developed in a new device, the double walled pot, by Richards (4). Here, the plants in the irrigator must pull against the weight of the column of supply water through a tube reaching to a reservoir at a lower level than the irrigator itself. In the double walled pot, Richards and Loomis (5) have found a decreasing degree of control of the soil moisture the lower one departs from the moisture equivalent. At the lower moisture contents, the water is lost from the container much more rapidly than it can be replaced because of the low rate of water movement in dry soil. The soil in the container may reach the wilting percentage and the plants growing therein remain unwilted if their roots are in contact with the source of supply through the porous clay walls of the container. In the apparatus described in the present paper, a much simpler system of water control was used, although one which has its limitations. At low moisture percentages there is difficulty in supplying moisture at a rate sufficiently high to maintain the certain desired low soil moisture which represents the actual water available to the roots of plants growing in the irrigator. Materials and methods