Calcium Lactate Treatment Research Articles

Calcium lactate treatment modulated fatty acid metabolism to attenuate senescence in ‘Jinfeng’ pear fruit during storage

Fatty acid metabolism not only affects cell membrane functionality but also correlates with the fruit quality and postharvest senescence. This study aims to assess the influence of calcium lactate immersion on lipid metabolism and senescence in ‘Jinfeng’ pear fruit during room temperature storage. The results demonstrated that calcium lactate effectively suppressed malondialdehyde content, respiratory rate, mass loss, and ethylene release, as well as phospholipase D (PLD), hydroperoxide lyase (HPL), lipoxygenase (LOX), lipase (LPS), alcohol acyltransferase (AAT), and alcohol dehydrogenase (ADH) activities in ‘Jinfeng’ pears. Additionally, calcium lactate resulted in an up-regulation of the gene expression levels associated with fatty acid biosynthesis, including PcACC, PcFabG, PcFabI, PcFabZ, PcKASII, PcACP, and PcFAD. Furthermore, there was an increase in the expression of genes involved in fatty acid elongation, such as PcKCS4, PcKCS6, PcKCS7, PcKCS10, PcLACS2, PcLACS4, PcLACS8, and PcCER. Conversely, it caused a down-regulation of the gene expression levels associated with fatty acid degradation, including PcLOX, PcAAT, PcADH, PcPLD, PcACD, PcECH, and PcACOX3. Simultaneously, calcium lactate treatment diminished the content of palmitic acid, while elevating the contents of linolenic acid, linoleic acid, and oleic acid. In summary, postharvest calcium lactate-immersed can efficaciously retard senescence of ‘Jinfeng’ pear fruit through regulating fatty acid lipid metabolism.

Attenuating sugar spot and retaining quality of banana fruits by combined use of hot water and calcium lactate during storage.

Combined use of hot water (HW) treatment and calcium lactate (CL) is a promising postharvest approach to preserve the food value and prolong the shelf life of fruits. The present experiment aims to determine the physiological loss in weight, firmness, respiration rate, ethylene and biochemical attributes of banana fruits treated with hot water (50 °C for 7 min) and aqueous CL dipping (1, 2, and 3% for 2 min). Treated fruits were stored under ambient conditions (22-25°C temperature and 60-65% of relative humidity) for up to 9 days. The study showed that combined use of HW and CL (3%) maintained higher hue angle, peel firmness (4.4 N), reduced decay loss (10.63%), respiration and ethylene evolution rate of stored fruits. Also, CL treatments (3%) with HW proved the best which reduced 6-fold sugar spot and 1.5-fold decay loss over untreated fruits. At the end of storage sensory parameters such as mouthfeel, peel colour and overall acceptability (score 6.9) were recorded higher in HW and CL 3% treated fruits. The findings indicated that pre-storage combined use of HW and CL has a great potential to preserve quality, delay ripening, and reduce sugar spots, and postharvest decay loss in banana fruit without any adverse effect on consumer appeal.

Improving the quality of ‘Keitt’ Mango using pre-harvest calcium lactate treatment and post-harvest applications of kojic and ascorbic acids

ABSTRACT This study intended to enhance fruit quality, extend shelf life and maintain quality of ‘Keitt’ mango (Mangifera indica L.) by using edible compounds without affecting quality or taste. Pre-harvest foliar treatment using calcium lactate (CaL) was applied at 1 and 2% alone or in combination with one of the post-harvest dipping treatments of 2% ascorbic acid (AsA) or 0.3% kojic acid (KA), before storage at 4°C for 12 days during two successive seasons. Pre-harvest treatment with calcium lactate at 2% significantly enhanced the quality of ‘Keitt’ mango fruits at harvest. It was observed that all the conducted treatments were effective in maintaining the quality of the pre-prepared ‘Keitt’ mango as compared to the untreated ones. Pre-harvest application of 2% CaL + post-harvest 2% AsA was the most effective treatment under experimental conditions in terms of total phenols, ascorbic acid, TSS/acid ratio, overall appearance, colour purity, browning incidence, and decay percentage. CaL at 2% showed the lowest significant values of CPLW and it maintained the highest significant firmness compared with control.

Investigating the impacts of harvest stages, citric acid and calcium lactate treatments on changes in quality attributes and natural microbiota of minimally processed litchi during storage

The study investigated the changes in quality of minimally processed litchi arils, harvested at two different dates (H) and treated with citric acid (1%, T1), calcium lactate (1%, T2), and citric acid (1%) + calcium lactate (1%) (T3) for 2 min. Treated litchi arils and non-treated (control) were packed in punnets and stored at 1°C for 12 days and sampled every 3 days. To simulate consumer shelf life conditions, at each sampling day, additional samples were transferred to 10°C and stored for 2 days. The interaction effects of harvest dates, postharvest treatments, and storage duration significantly influenced TA, PH, radical scavenging activity, and ascorbic acid content of the litchi arils (p < .05). At the end of storage, litchi arils harvested early and treated with T3 presented higher radical scavenging activity (36.6 mmol AAE/ml). In contrast, fruit harvested late and treated with T3 had higher ascorbic acid content (72.9 μg/ml) at the end of the storage. Browning was significantly reduced in litchi arils harvested early and treated with T3 (−534.5) at the end of storage. The natural fungal profile on litchi arils was influenced by harvest date, pre-treatments, cold storage, and duration. Colletotrichum gloeosporroides was found to be the most dominant, followed by Phomopsis sophorae in early-harvested litchi arils before storage. However, Diaporthe sp. were found to be the most dominant during cold storage. For the late harvest litchi arils, Chaetomium sp., and Trametes polyzona were observed to be dominant. Practical applications The greatest postharvest limitation to litchi fruit is pericarp browning, which causes consumers rejection in the market while the edible portion is still in excellent condition. Following the rejection of sulfur dioxide fumigation as a method of pericarp browning control, minimal processing of litchi fruit at different harvest stages and pre-treated with organic acids (citric acid, calcium lactate, and their combination) was carried out. The findings from the study showed that minimally processed litchi arils treated with citric acid alone or combined with calcium lactate could potentially maintain its freshness.

Effects of hot water and calcium lactate treatments on fresh-cut quality of papaya

Purpose: Papaya is one of the most common fruits which has been produced in southern part of Iran for fresh consumption. Demand for fresh-cut products has increased due to the changes in consumer attitudes. However, fresh-cut papaya is prone to softening during storage. This study carried out to determine effects of calcium lactate and hot water treatments (HWT) for maintaining fresh-cut papaya quality. Research method: After preparing fresh cut cubes of papayas, the pieces were dipped in calcium lactate (CaL) or combined with HWT. Physico-chemical parameters including calcium concentration (Ca), firmness and soluble solids concentration, catalase and peroxidaseactivities, pectin methyl esterase (PME) and polygalacturonase activities (PG),total phenolic content and radical scavenging activities, and microbial growth were measured during 9 days of storage at 5 ◦C. Findings: At the end of storage, CaL treatment combined with HWT increased calcium (Ca) concentration, catalase activity, total phenolic content and radical scavenging activities (DPPH) of papaya slices, but decreased peroxidase, PG and PME activities compared to the control. In addition, these treatments reduced microbial growth compared to the control. Limitations: No limitations were encountered. Originality/Value: Both HWT with CaL showed potential for increasing markeabitity on fresh cut papaya with their generally recognized as safe status for consumers.

Calcium permeation property and firmness change of cherry tomatoes under ultrasound combined with calcium lactate treatment.

This study aimed to investigate the effect of ultrasound combined with calcium lactate (2%, w/v) treatment (U + Ca) on calcium permeation and firmness of cherry tomatoes. Calcium distribution and fruit pectin nanostructure were also analysed by transmission electron microscope (TEM) and atomic force microscopy (AFM), respectively. The firmness (31.45 N) was maintained when ultrasound energy density was 20 W/L for 15 min at 15 °C. The Ca content increased in U + Ca treated fruit. Meanwhile, the Peleg's model could be used to express the change of solid gain in cherry tomatoes under ultrasound treatment at 15, 20, and 25 °C. According to the AFM results, the width (≥40 nm) and length (≥2 μm) of chelate-soluble pectin (CSP) and sodium carbonate-soluble pectin (SSP) chains with large frequency was observed in U + Ca treated fruit. Under desirable conditions (15 °C, 15 min, 20 W/L), ultrasound combined with calcium lactate could maintain the quality of cherry tomatoes.

Effect of calcium lactate in combination with hot water treatment on the nutritional quality of persimmon fruit during cold storage

Abstract Quality reduction and quick softening, occurring after harvest, limit shelf-life of persimmon fruit. In the present research, the effects of hot water and calcium lactate treatments on maintaining the firmness and preserving the quality of persimmon fruit during cold storage were investigated. ‘Karaj’ persimmon was harvested at commercial maturity stage and treated with hot water at three levels of 25 °C for 25 min, 45 °C for 30 min and 50 °C for 20 min, and calcium lactate at three levels of 0, 0.5 and 1%, and their combinations. The treated fruits were then stored at 1 °C with a relative humidity of ≥80%. At 20 and 40 days of the storage, fruits were removed from the refrigerator and some traits were evaluated three days after storage under shelf-life conditions. The evaluated traits were calcium content, firmness, weight loss, soluble tannin content, carotenoid, ascorbic acid, antioxidant capacity, total soluble solids and titratable acidity. The results showed that the amount of calcium in fruit tissue increased only in calcium lactate treatment, and hot water treatment showed a small effect on the trait. The combination of calcium lactate and hot water treatments caused higher effect on maintaining the firmness, controlling weight loss and preserving the quality of fruit when compared to applying each treatment alone. Furthermore, the treatments maintained antioxidant properties of the fruits during cold storage by maintaining the amount of soluble tannin, carotenoid and ascorbic acid contents. Thus, combined treatment of hot water and calcium lactate can be used to enhance antioxidant properties and preserve nutritional quality of persimmon fruits during postharvest storage.

Gibberellic acid promoting phytic acid degradation in germinating soybean under calcium lactate treatment.

Phytic acid as a phosphorus storage vault provides phosphorus for plant development. It is an anti-nutritional factor for humans and some animals. However, its degradation products lower inositol phosphates have positive effects on human health. In this study, the effect of gibberellic acid (GA) on phytic acid degradation under calcium lactate (Ca) existence was investigated. The results showed that Ca + GA treatment promoted the growth status, hormone metabolism and phytic acid degradation in germinating soybean. At the same time, the availability of phosphorus, the activity of phytic acid degradation-associated enzyme and phosphoinositide-specific phospholipase C (PI-PLC) increased. However, the relative genes expression of phytic acid degradation-associated enzymes did not vary in accordance with their enzymes activity. The results revealed that GA could mediate the transport and function of calcium and a series of physiological and biochemical changes to regulate phytic acid degradation of soybean sprouts. © 2017 Society of Chemical Industry.

Effect of Vacuum Impregnation Combined with Calcium Lactate on the Firmness and Polysaccharide Morphology of Kyoho Grapes (Vitis vinifera x V. labrusca)

The effects of vacuum impregnation (VI) with 2% calcium lactate treatment on the VI properties (obtained from hydrodynamic mechanism and deformation–relaxation phenomena models), firmness, and pectin of Kyoho grapes were investigated. Fruit pectin was analysed by atomic force microscopy (AFM). VI was applied for 10–35 min at 25–45 °C and 5 kPa. The maximum values of effective porosity, ee (0.606%), and volume fraction, X (0.588%), occurred at 35 °C when the VI time was 15 min. No change was observed in the volumetric deformation (γ ≈ 0) of the grapes after the impregnation. The firmness significantly increased at 35 °C VI (from 12.93 to 14.47 N). According to the AFM results, calcium mainly inhibited the degradation of chelate-soluble pectin and sodium carbonate-soluble pectin short branches during the VI. Under the studied conditions, the validity of VI to incorporate calcium into fruit to improve the quality of grapes was verified, and a final corresponding product was obtained by VI.

The Improvement of Texture and Quality of Minimally Processed Litchi Fruit Using Various Calcium Salts

The efficacies of three calcium salts at different concentrations (0.5–3%) and temperatures (4, 25 and 50C) were studied to improve texture and quality of litchi arils cv. “Jugkapat.” A peroxyacetic acid was used as sanitizer in pre- (100 mg/L, 3 min) and post-deseeding steps (50 mg/L, 1 min). The arils were immersed in 1% calcium chloride, 2% calcium propionate at 25C and 2% calcium lactate at 50C had the best firmness. All calcium salts decreased the respiration rate by 1.5 to 2 folds, reduced juice leakage and delayed microbial growth during 12-day storage at 2 ± 1C. A pink color was developed in calcium lactate treatment. For microstructure study, calcium chloride reinforced the cell wall and maintained the cell turgor better than other two salts. Hence, calcium chloride could be the best salts to maintain texture, quality and extended the shelf-life of litchi arils to 9 days. Practical Applications Minimal process is one of the simple and convenient methods that preserve nutritional value and appearance of which was treated fresh agricultural produce. The minimally processed litchi fruit which was treated with calcium salts in combination with peroxyacetic acid, a sanitizer, had the potential to improve the firmness, prolong quality and shelf-life along with minimum physical damage. One of the major problems is that the whole litchi fruit has a short shelf-life due to the fact that pericarp turns brown within 2–3 days after harvest, resulting in a rejection by the market even though the edible arils still remain in excellent condition. This study presents the alternative method to preserve the litchi arils by minimal processing technology.

Influence of calcium lactate and modified atmosphere on respiration rate, optical and mechanical properties of sliced persimmon

The aim of this study was to evaluate the effect of a modified atmosphere (5% and 10% of CO2) and calcium lactate treatment on the respiratory metabolism of minimally processed persimmon. A static system to measure changes in the composition of the headspace was used. Composition, texture and colour were also analysed. Persimmon slices were evaluated immediately after the washing treatment and after the O2 composition had decreased to 17% to avoid changes in the metabolic pathway. All samples were stored at 4 ℃. The results showed that modified atmosphere did not affect compositional properties, although there was a slight increase in pH values at the end of each treatment. Calcium lactate treatment reduced the respiration rate, in terms of O2, in samples kept in air. Additionally, a calcium lactate effect was immediately observed on mechanical properties after the washing stage. On the other hand, luminosity and b* coordinate decreased in unwashed and calcium lactate samples kept in 5% CO2.

Nutritional quality changes of fresh-cut tomato during shelf life

Effects of dip treatments on nutritional quality preservation during the shelf life of fresh-cut tomato (Licopersicum esculentum Mill.) cv. Eufrates were investigated. Fresh-cut tomatoes were dipped in solutions of 2% ascorbic acid, citric acid, and calcium lactate for 2 min, then stored at 4°C for 20 days. Color (L*, a*, and b*), firmness, °Brix, phenolics, ascorbic acid content, antioxidant activity (DPPH), and sugars were measured during storage. Pathogen development was monitored, and a sensory evaluation was performed. Ascorbic acid was better in maintaining firmness. No treatments significantly affected °Brix, color, or sugars. Ascorbic acid maintained a higher antioxidant capacity, phenolics, and ascorbic acid content, and was better at reducing bacterial growth, while citric acid treatment was better at prevention of yeast and molds proliferation. Fresh-cut tomatoes showed good quality after 10 days of shelf life, except for flavor with the calcium lactate treatment. Ascorbic acid treatment better preserved the general and nutritional quality parameters.

The effect of Ca2+ and cellular structure on apple firmness and acoustic emission

This study presents the influence of calcium lactate treatment (0–6 %) and cellular composition on two mechanical attributes: firmness and total acoustic emission (AE) events registered in the puncture test of apple tissue. The experiment was performed on five apple cultivars stored for nine months in a normal or controlled atmosphere. The microstructure was characterized quantitatively on control samples by confocal scanning laser microscope followed by image analysis. The mean area and perimeter of detected objects, which were either cells or spaces, and estimated cell wall fraction were used for the characterization of the tissue microstructure. Treatment with increased Ca2+ concentration caused a significant increase in firmness and total AE events. The increase was more pronounced in the case of total AE events which better reflected an increase in brittleness of apple tissue than firmness parameter. The effect was particularly positive in the case of very soft apples (stored in a normal atmosphere) due to greater extent of de-esterification of homogalacturonan. Analysis of the results, together with a review of the literature, suggests that calcium importantly changes the cracking mode of tissue, from intercellular debonding to cell wall rupturing. Firmness and the total AE events significantly relate negatively to the object’s size and positively to estimated cell wall fraction. A rough accordance of the number of split cells open across cell walls by puncture probe and the total AE events registered in the test, which was saturated in high Ca2+ concentrations, was noticed.

Changes in Texture and Dietary Fiber of the Brown Alga Undaria Pinnatifida by Various Processing Methods

To elucidate the effects of simple processing on seaweed as food, several methods were applied to Undaria pinnatifida. In this study, 1) boiling in the NaCl solution or 2) soaking in acetic acid, 3) calcium lactate or 4) sodium gluconate solution were performed for U. pinnatifida. After processing, dietary fiber content, breaking strength and molecular weight of extracted alginate were measured. Breaking strengths and insoluble dietary fiber contents decreased as boiling time increased. Breaking strength of U. pinnatifida after calcium lactate treatment was higher than that for sodium gluconate treatment. Molecular weight of alginate was not affected by processing, excepting heating treatment. Our results indicate that processing methods other than heating primarily affect the texture of seaweed products.

Effect of ozone and calcium lactate treatments on browning and texture properties of fresh‐cut lettuce

AbstractThe effects of three treatments, 1 mg L−1 ozone at 18–20 °C, 15 g L−1 calcium lactate (CLac) at 50 °C and a combination thereof, were compared on fresh‐cut lettuce over 10 days of refrigerated storage. Respiration rate, browning and texture were examined as main quality indicators. The use of ozone produced a significantly (P &lt; 0.05) higher oxygen decline than the use of CLac (from day 3 to day 10). At the end of storage, CLac (alone or combined with ozone) samples had higher oxygen content (∼9%) than ozone samples (∼6%). Enzymatic activity decreased significantly (P &lt; 0.05) in ozone samples. Polyphenol oxidase activity in fresh‐cut lettuce treated with ozone (alone or combined with CLac) showed lower values on day 1 (&lt;2500 units g−1) and at the end of storage (&lt;3000 units g−1) than CLac samples (4000–4800 units g−1). Ozone also reduced peroxidase activity to ∼300 units g−1 after treatment. Finally, pectin methylesterase activity was also reduced with ozone, showing a negative effect on textural properties. Data suggested that CLac maintained quality markers better than treatments with ozone and ozone/CLac combination over 10 days of storage. Copyright © 2006 Society of Chemical Industry

Improvement in texture using calcium lactate and heat-shock treatments for stored ready-to-eat carrots

The use of calcium lactate solutions has been shown to be a healthy alternative to chlorine washing in order to maintain the shelf-life of fresh-cut products. The aim of this research was to analyse the effects of calcium lactate (15 g L −1) treatment at 25 °C and 50 °C (heat-shock) on the textural properties of sliced carrots and to compare those with the chlorine treatment (120 mg L −1) widely used in industry. Several direct and indirect markers of textural changes in carrots during storage were used: Instron textural analysis, Cryo-SEM and optical microscopic, sensory analysis, pectin methylesterase (PME) activity, calcium content and water activity. Samples treated with calcium lactate maintained texture significantly ( p < 0.05) better than samples treated with chlorine throughout storage. Calcium lactate treatment produced a reduction in the water activity in sliced carrots and a higher firmness (Instron analysis) than chlorine treatment. In addition, combined use of heat-shock and calcium lactate treatment increased PME activity significantly when compared to the other treatments, results that were confirmed by sensory analysis. Cryo-SEM analyses showed that combined heat-shock and calcium lactate treatment was more effective in maintaining the turgor of cortex tissue cells and reduced the extent of lignification at cutting-edge areas. The use of calcium lactate combined with heat-shock is a promising washing method for fresh-cut carrots in order to preserve their texture and improve their nutritional value, avoiding the use of chlorine washing.

Comparison of calcium lactate with chlorine as a washing treatment for fresh‐cut lettuce and carrots: quality and nutritional parameters

AbstractThe efficacies of calcium lactate and chlorine washing treatments of fresh‐cut lettuce and carrots were compared during storage at 4 °C over 10 days. The gas composition of packages, colour, enzyme activity, texture, sensory attributes, microflora and levels of ascorbic acid and carotenoids were evaluated at 1, 3, 7 and 10 days. Calcium lactate treatment was not significantly different to chlorine treatment (p &lt; 0.05) in terms of maintaining colour, texture and acceptability of fresh‐cut lettuce and carrots during the entire storage period. The washing treatments did not affect levels of ascorbic acid of fresh‐cut lettuce or carrots. Carotenoid levels were higher in calcium lactate‐treated carrots than chlorine‐treated samples at the end of storage. Mesophilic, psychrotrophic and lactic acid bacteria counts were not significantly different between treatments for both vegetables. Copyright © 2005 Society of Chemical Industry

Calcium Lactate Treatment after Salting of Chinese Cabbage Improves Firmness and Shelf-life of Kimchi

In order to enhance the firmness and shelf-life of kimchi, as well as to increase the content of well-absorbed digestible calcium, the effect of calcium lactate (CaL) treatment of salted Chinese cabbage on pH, titratable acidity, total microbes, lactic acid bacteria, alcohol insoluble substance (AIS) content, firmness, mineral content and tissue structure were investigated. Treatment with the Cal solution increased pH and decreased titratable acidity, which was more pronounced at higher concentrations. The edible period evaluated by pH was 7～8 days for non-treated kimchi, 10 days for 1% treated kimchi, 15 days for 2% treated kimchi and 20 days for 3% treated kimchi. Total microbes were reduced, but lactic acid bacteria counts were higher in the treated group. CaL treated kimchi showed higher AIS content and firmer texture, which was more conspicuous in the 2 and 3% CaL treated groups. Calcium content in kimchi fermented for 15 days was 40.75～41.53 mg%, which is 42～45% higher than that in the control group. The sodium content was 23～54% less in the treated groups. The epidermis and vascular bundle tissue of kimchi fermented for 15 day was damaged more severely in the control group than in the treated group. CaL treated kimchi has a crispier taste and the development of sour taste was delayed. Therefore, addition of CaL can produces a kimchi with high calcium as well as superior texture and shelf-life, when adjusting the concentration according to the fermentation periods.

Effects of calcium salts on beef longissimus quality

The objective of this research was to evaluate the effects of injection marination with calcium salts on beef longissimus quality traits. Strip loins were injected (11% by weight) with distilled water or a 0.1, 0.2, or 0.3 M solution of calcium ascorbate, calcium chloride, or calcium lactate. Non-injected loins served as controls. Visual and instrumental color evaluations indicated that calcium ascorbate accelerated myoglobin oxidation, and increasing molar concentration of any calcium salt caused faster ( P<0.05) discoloration. Aerobic microbial plate counts were lower ( P<0.05) for treatments containing calcium lactate than those with calcium chloride or calcium ascorbate. Calcium ascorbate inhibited lipid oxidation whereas calcium lactate and calcium chloride appeared to be pro-oxidants of lipid oxidation. No differences for Warner-Bratzler shear force or sensory panel tenderness were found among the calcium salts; however, 0.3 M treatments had lower shear values and were judged more tender than 0.1 M treatments. Calcium ascorbate and calcium chloride treatments resulted in less ( P<0.05) beef flavor and more ( P<0.05) off-flavors than calcium lactate treatments. In addition, 0.1 M treatments had higher ( P<0.05) beef flavor scores while 0.3 M treatments had higher ( P<0.05) off-flavor scores. Considering the effects on color life, microbial inhibition, shear force, and sensory traits, we recommend injecting beef longissimus with a 0.1 M solution of calcium lactate to enhance both uncooked and cooked quality.

Factors affecting parathyroid hormone-induced hypophosphatemia and 32P specific activity in thyroparathyroidectomized rats.

Plasma changes in calcium, phosphate, and their radionuclides were studied in thyroparathyroidectomized (TPTX) rats treated with parathyroid hormone (PTH) for 8 h, this treatment starting 10 h after injection of45Ca and32P. Prior to intravenous infusion or hourly injections of PTH (10 mU/g/h), rats were maintained in one of three ways: on an extended fast (24 h); on a partial fast (10 h); or provided with 10% glucose and 1% calcium lactate overnight as a substitution for solid food. The pattern of change for plasma calcium,45Ca, and45Ca specific activity (S.A.) produced by PTH was not affected by these dietary conditions. The changes in phosphate were as follows: During the experimental (8 h) period, the rate of loss of32P from plasma in control rats was proportional to the length of the fast. This suggests that32P was released into plasma during the experimental period proportional to the ready availability of soft tissue glucose. In rats on an extended fast, PTH was phosphaturic, hypophosphatemic, and increased the rate of loss of32P from plasma without affecting32P S.A. values. In rats fasted for only 10 h, PTH produced similar effects on plasma phosphate and plasma32P values, but also caused a significant fall in plasma32P S.A. After glucose and calcium lactate treatment, PTH-induced phosphaturia was temporarily lost and the marked hypophosphatemia was replaced with a slight hyperphosphatemia. Plasma32P values also rose slightly; therefore, no effect on32P S.A. was produced. It is concluded from these studies that as the result of the phosphaturia caused by PTH, the hypophosphatemia which is produced automatically changes the phosphate gradient between various body compartments, causing phosphate entry into plasma. The authors postulate that this phosphate entering plasma is withdrawn primarily from bone fluid and bone.