Studies on keeping-quality of vegetables and fruits. III. Changes in sugar and organic acid contents accompanying the chilling-injury of eggplant fruits

The mechanism of chiiling-injury in fruits of eggplants (Solanum melongena L. cultivar ‘Hyonaga’) was investigated by determining the sugar and organic acid content during cold storage and after exposure to low temperature for various periods. Fructose, glucose and maltose were detected, and totalled more than 96% of total sugar on the initial day. Total sugar content increased to 30% higher than the initial day after 2 days of cold storage, and after that decreased gradually, while in 20° C-stored fruits it decreased sharply. Fructose, glucose and maltose increased rapidly after transfer from 1° C to 20° C. Succinic, oxalic, malic and citric acid were detected before storage. Malic and citric acid were found to be the main organic acids. The ratio of malic/citric acid in fruits stored at 1°C decreased during storage, while after storage at 20°C it increased. The ratio in fruits after transfer from 1°C to 20°C increased rapidly during the time course. The ratio of malic/citric acid ranged from 6.0 to 6.8 in healthy fruits, while it was below 5.9 or above 7.3 in chilled fruits. It is suggested that according to this ratio the degree of chilling-injury of eggplant fruits might be foreseen.     

Microanatomy of the terminal air spaces of Baird's beaked whale (Berardius bairdii) lungs

The terminal airways and microvasculature of five adult Baird's beaked whales (Berardius bairdii) lungs have been examined by means of light and scanning electron microscopy of corrosion casts. The respiratory system of the Baird's beaked whale has various anatomical features which allow them to attain great depths and remain submerged for long periods. The whale lung has components including hyaline cartilage and smooth muscle throughout, reaching as far as the peripheral bronchi, sphincters surrounding the terminal bronchioles, the thick alveolar septa with a connective tissue core and a bi-layer capillary bed, and a distinctive venous plexus of the pulmonary veins. The well-developed venous plexuses of the pulmonary vein are found in the interlobular connective tissue, and around the airways and pulmonary arteries with close apposition. The hyaline cartilage throughout the airways may increase the effective dead air space that accommodates most of the air forced from the collapsed alveoli during a dive. The sphincter might serve as a cock for regulating buoyancy and for trapping air in the alveoli to prevent their complete collapse and a sucking in of alveolar tissue as the dive becomes deeper. The venous plexuses might be for pooling the large volume of blood in the lung to conserve oxygen for deep and prolonged diving.     

Secretory pattern and regulatory mechanism of growth hormone in cattle

The ultradian rhythm of growth hormone (GH) secretion has been known in several animal species for years and has recently been observed in cattle. Although the physiological significance of the rhythm is not yet fully understood, it appears essential for normal growth. In this review, previous studies concerning the GH secretory pattern in cattle, including its ultradian rhythm, are introduced and the regulatory mechanism is discussed on the basis of recent findings.     

Malaria in cynomolgus monkeys used in toxicity studies in Japan

Plasmodium spp. protozoa cause malaria and are known to infect humans and a variety of animal species including macaque monkeys. Here we report both our experience with malaria recrudescence in cynomolgus monkeys (Macaca fascicularis) in a toxicity study and the results of a survey on Plasmodium infection in cynomolgus monkeys imported to Japan for laboratory use. A cynomolgus monkey from the toxicity study presented with severe anemia and Plasmodium protozoa in erythrocytes on a thin blood smear and was subsequently diagnosed with symptomatic malaria. In this animal, congestion and accumulation of hemozoin (malaria pigment) in macrophages were noted in the enlarged and darkly discolored spleen. As a follow-up for the experience, spleen sections from 800 cynomolgus monkeys in toxicity studies conducted between 2003 and 2013 were retrospectively examined for hemozoin deposition as a marker of Plasmodium infection. The origin of the animals included Cambodia, China, Indonesia, and Vietnam. Hemozoin deposition was confirmed in 44% of all examined monkeys. Monkeys from Indonesia showed the highest incidence of hemozoin deposition (approx. 80%). A high prevalence of Plasmodium infection in laboratory monkeys was also confirmed with polymerase chain reaction (PCR) by using Plasmodium genus-specific primers. Although Japan is not a country with endemic malaria, it is important to be aware of the prevalence and potential impact of background infection with Plasmodium spp. and recrudescence of symptomatic malaria in imported laboratory monkeys on pharmaceutical toxicity studies.     

Distribution of ascorbic acid in potato tubers and in home-processed and commercial potato foods

HPLC was used to analyze the content of ascorbic acid (AA) in tubers of four Korean potato cultivars (Chaju, Sumi, Deso, and Dejima), in a series of baked, boiled, braised, fried, microwaved, pressure-cooked, and sauteed potato slices from the Dejima cultivar and in 14 commercial Korean and 14 processed potato foods sold in the United States (chips, snacks, mashed potatoes, fries). The AA content for the four cultivars ranged from 16 to 46 mg/100 g of fresh weight. The distribution of AA in each of the eight potato slices (sticks, plugs) cut horizontally from the stem end of the Dejima potato ranged from 6.8 to 19.3% of the total. The corresponding distribution in seven sticks cut vertically was much narrower, ranging from 11.7 to 17.5% of the total. Losses of AA in water (pH 5.2) were significantly greater than in 5% metaphosphoric acid (pH 1.0). Less degradation occurred in water solutions of the vitamin stored at 1 degree C than at 25 degrees C. Losses of AA observed during home-processing of three varieties with low (Dejima, 16 mg/100 g), intermediate (Sumi, 32 mg/100 g), and high (Chaju, 42 mg/100 g) AA contents were as follows: boiling in water, 77-88%; boiling in water containing 1-3% NaCl, 61-79%; frying in oil, 55-79%; sauteing, 61-67%; pressure-cooking in water, 56-60%; braising, 50-63%; baking, 33-51%; and microwaving, 21-33%. The content of the Korean foods ranged from trace amounts to 25 mg/100 g and that of the U.S. foods from 0.4 to 46 mg/100 g. These results permit optimization of the vitamin C content of the diet by (a) using high-vitamin C potato varieties such as Chaju, (b) selecting sticks cut horizontally for frying, (c) baking or microwaving rather than boiling or frying, and (d) selecting commercial potato foods with a high vitamin C content.     

Basal body temperature method for detecting ovarian cycle in the Captive Beluga (Delphinapterus leucas)

The relationship between basal body temperature and circulating progesterone levels were investigated in a female beluga. Body temperature and serum concentrations of progesterone were measured daily and at 2-4 week intervals respectively, in a female beluga that was in captivity for 7 years between 1996 and 2003. The beluga first ovulated in April, 2000 (13 years old). Thereafter, serum concentrations of progesterone showed cyclic changes, indicating that the ovulatory cycle had started. Serum concentrations of progesterone ranged from 0.1 ng/ml to 15.7 ng/ml. Body temperature also showed cyclic changes during the estrous cycle. Body temperature ranged from 34.9 to 35.9 C, and tended to reach the peak during the high progesterone phase. Mating behavior was observed during the low body temperature phase. The changes in body temperature positively correlated with the circulating progesterone levels. The length of the estrous cycle was 36.7 +/- 3.9 (mean +/- SEM) days based on the intervals between the days of mating behavior. This is the first report demonstrating that body temperature clearly changes during the estrous cycle in a captive female beluga. The present finding suggests that measurement of body temperature is a useful method for detecting the ovarian cycle of the beluga in captivity.     

Anticarcinogenic effects of glycoalkaloids from potatoes against human cervical, liver, lymphoma, and stomach cancer cells

Methods were devised for the isolation of large amounts of pure alpha-chaconine and alpha-solanine from Dejima potatoes and for the extraction and analysis of total glycoalkaloids from five fresh potato varieties (Dejima, Jowon, Sumi, Toya, and Vora Valley). These compounds were then evaluated in experiments using a tetrazolium microculture (MTT) assay to assess the anticarcinogenic effects of (a) the isolated pure glycoalkaloids separately, (b) artificial mixtures of the two glycoalkaloids, and (c) the total glycoalkaloids isolated from each of the five potato varieties. All samples tested reduced the numbers of the following human cell lines: cervical (HeLa), liver (HepG2), lymphoma (U937), stomach (AGS and KATO III) cancer cells and normal liver (Chang) cells. The results show that (a) the effects of the glycoalkaloids were concentration dependent in the range of 0.1-10 mug/mL (0.117-11.7 nmol/mL); (b) alpha-chaconine was more active than was alpha-solanine; (c) some mixtures exhibited synergistic effects, whereas other produced additive ones; (d) the different cancer cells varied in their susceptibilities to destruction; and (e) the destruction of normal liver cells was generally lower than that of cancer liver cells. The decreases in cell populations were also observed visually by reversed-phase microscopy. The results complement related observations on the anticarcinogenic potential of food ingredients.     

Analysis of eight capsaicinoids in peppers and pepper-containing foods by high-performance liquid chromatography and liquid chromatography-mass spectrometry

Diverse procedures have been reported for the isolation and analysis of secondary metabolites called capsaicinoids, pungent compounds in the fruit of the Capsicum (Solanaceae) plant. To further improve the usefulness of high-performance liquid chromatography (HPLC), studies were carried out on the analysis of extracts containing up to eight of the following capsaicinoids: capsaicin, dihydrocapsaicin, homocapsaicin-I, homocapsaicin-II, homodihydrocapsaicin-I, homodihydrocapsaicin-II, nonivamide, and nordihydrocapsaicin. HPLC was optimized by defining effects on retention times of (a) the composition of the mobile phase (acetonitrile/0.5% formic acid in H2O), (b) the length of the Inertsil column, and (c) the capacity values (k) of the column packing. Identification was based on retention times and mass spectra of individual peaks. Quantification was based on the UV response at 280 nm in HPLC and recoveries from spiked samples. The method (limit of detection of approximately 15-30 ng) was successfully used to quantify capsaicinoid levels of parts of the pepper fruit (pericarp, placenta, seeds, and in the top, middle, and base parts of whole peppers) in 17 species of peppers and in 23 pepper-containing foods. The results demonstrate the usefulness of the method for the analysis of capsaicinoids ranging from approximately 0.5 to 3600 microg of capsaicin equiv/g of product. The water content of 12 fresh peppers ranged from 80.8 to 92.7%. The described freeze-drying, extraction, and analysis methods should be useful for assessing the distribution of capsaicinoids in the foods and in defining the roles of these biologically active compounds in the plant, the diet, and medicine.     

Tracer studies on the incorporation of [2-14C]-DL-mevalonate into chlorophylls a and b, alpha-chaconine, and alpha-solanine of potato sprouts

Chlorophyll and glycoalkaloids are synthesized in different parts of the potato plant including leaves, tubers, and sprouts. Although light stimulates the biosynthesis of both constituents, the question of whether the two biosynthetic pathways are under the same genetic control has not been resolved. This study investigated the dynamics of incorporation of labeled [2-(14)C]-DL-mavalonate into chlorophyll a, chlorophyll b, and the glycoalkaloids alpha-chaconine and alpha-solanine in potato sprouts after 7 and 14 days of storage in the light and in the dark. No chlorophyll synthesis occurred in the dark. Fractionation of the "glycoalkaloid" extract followed by high-performance liquid chromatography produced four peaks. The fractions were collected and analyzed for radioactivity. About 80% of the radioactivity resided in fraction 1, the composition of which is unknown. Two of the fractions, with 1-14% of the original label, were alpha-chaconine and alpha-solanine. The radioactivity derived from mevalonate largely resides in unidentified compound(s) eluting as a single peak on the HPLC column before the peaks associated with the glycoalkaloids. The specific radioactivity of alpha-chaconine and alpha-solanine increased approximately 2-fold in going from 7 to 14 days of exposure in the light and in the dark. These and additional observations point to the near identity of the dynamics of biosynthesis of the two glycoalkaloids. These data also implicate a non-mevalonate pathway for the synthesis of both chlorophylls and the glycoalkaloids and are consistent with independent genetic control of the concurrent formation of the two classes of compounds during greening of potatoes.     

ECG and heart rate determination in fetal cattle using a digital signal processing method

A method of recording the fetal electrocardiogram (ECG) and heart rate (HR) is described. An abdominal lead and a thoracic lead were used to measure the fetal ECG and maternal ECG, respectively. The maternal component in the abdominal lead measurement was estimated by a digital adaptive filter using the thoracic lead measurement as a reference. By suppressing the estimated maternal components in the abdominal lead, the fetal ECG could be detected. The beat‐by‐beat fetal QRS complex peaks were determined by a digital matched filter from the fetal ECG enhanced in this way. The method was trialed in 10 pregnant Holstein cows at gestational periods ranging from 136 to 224 days. The results show that this method can extract the fetal ECG and determine the fetal HR from the raw noisy measurement data. The results suggest that the method would have applicability in monitoring fetal ECG as well as providing a non‐invasive, continuous HR profile during gestation, which will enable better understanding of the development of cattle fetuses before delivery.