Ppm Ascorbic Acid Research Articles

Antioxidant effects on retinyl palmitate stability and isomerization in nonfat dry milk during thermally accelerated storage

The effects of antioxidants on vitamin A oxidation and isomerization in nonfat dry milk (NFDM) were evaluated during thermally accelerated storage. High performance liquid chromatography was used to measure all-trans, 13-cis, 9-cis, and 9, 13-di-cis retinol present in two lots of antioxidant-treated, vitamin A and D fortified NFDM samples at zero, one, and two weeks of 50 °C storage. After two weeks, the NFDM sample retaining the most vitamin A was the one treated with butylated hydroxytoluene at 0.29 ppm with 250 ppm ascorbic acid; this treatment retained approximately 76% of its original retinol activity equivalents. The control retained significantly less than this: only 19% of its original vitamin A activity. Butylated hydroxytoluene in combination with ascorbic acid appears to be effective in the preservation of vitamin A in NFDM during heated storage; however, its use in dried beverage mixes is currently prohibited.

Influence of electrolytes and ascorbic acid supplementation on serum and erythrocytic indices of broiler chickens reared in a hot environment

Effect of supplementing drinking water with ammonium chloride, sodium bicarbonate, calcium chloride and ascorbic acid on haematology and selected serum indices of broiler chicks reared during high temperature and humified period was evaluated. A total of 200 one-day old Arbor acre broiler chicken strain was randomly allotted to five treatments: T1 (control-water without any supplement), T2 (0.5% ammonium chloride), T3 (0.5% sodium bicarbonate), T4 (0.5% calcium chloride), T5 (300 ppm ascorbic acid) in a completely randomized design. The packed cell volume, haemoglobin and albumin values obtained at day 28 and 49 varied significantly (p 0.05) different, while glucose levels of control group was significantly (p<0.05) higher than those on T3 at day 49. Ascorbic acid supplementation enhanced the haematological profile of birds while supplemental electrolytes ameliorated heat stress with more profound effects on serum indices of birds on sodium bicarbonate. Key words: Heat stress, ascorbic acid, haematological indices, serum metabolites, electrolytes, tropic environment.

EFFECT OF ASCORBIC ACID, BENZYL ADENINE AND PACLOBUTRAZOL ON GROWTH, YIELD AND SOME METABOLIC CONSTITUENTS OF SUNFLOWER PLANTS

A field experiment was conducted to study the effect of foliar spray of ascorbic acid (50 and 100 ppm), benzyl adenine (50 and 100 ppm) and paclobutrazol (25 and 50 ppm) on growth, yield and some physiological parameters of (Helianthus annuus var. Sakha 53). Ascorbic acid was more effective than other treatments in enhancing growth parameters during stage I, while benzyl adenine was most effective during stage II. Paclobutrazol seemed to be less effective regarding growth characteristics. All doses applied tended to increase photosynthetic pigments, total soluble carbohydrates and soluble proteins of sunflower plants. The changes in proteolytic, amylolytic and lipolytic activities were also recorded. This was associated by improving yield quality and the nutritional value of the seeds. The effect of paclobutrazol was superior to that of ascorbic acid, benzyl adenine on increasing yield components. The highest lipid % was recorded by 50 ppm of ascorbic acid, whereas the highest carbohydrates and proteins of the yielded seeds were observed with plants treated with 100 ppm benzyl adenine.

Exogenous ascorbic acid increases resistance to salt of Silybum marianum (L.)

Salinity stress has negative effects on agricultural yield throughout the world, affecting production whether it is for subsistence or economic gain. This study investigates the inductive role of vitamin C and its application mode in mitigating the detrimental effects of irrigation with diluted (10, 20 and 30 %) NaCl + water on Silybum marianum L. plants. The results show that 10% of salt water exhibited insignificant changes, while the higher levels impaired growth by reducing seed germination, dry weights of shoot and root, water status and chlorophyll contents. However, irrigation with salt water enhanced carotenoids and antioxidant enzyme activities. The detrimental effects of salt water were ameliorated by application of 100 ppm ascorbic acid (vitamin C). The inductive role of vitamin was associated with the improvement of seed germination, growth, plant water status, carotenoids, endogenous ascorbic acid and antioxidant enzyme activities. Moreover, vitamin C alone or in combination with 30% NaCl water increased the intensity of protein bands as well as synthesized additional new proteins with molecular weights of 205, 87, 84, 65 and 45 kDa. This could increase tolerance mechanisms of treated plants towards water salinity.

Amelioration of extreme temperature stress in alfalfa seedlings by vitamin C and vitamin B6

Concerns about the vulnerability of agricultural production to climate change are increasing. The establishment of seedlings at early growth stages of crop plants, one of the most important determinants of high yield, is severely affected by extreme temperatures. Therefore, efforts must be made to achieve high germination rate and vigorous early growth under extreme temperature conditions.Alfalfa is a perennial forage crop with high yield, good quality and high protein content, but is frequently exposed to extreme temperature conditions. The primary purpose of this investigation was to test the hypothesis that L-ascorbic acid (AsA) and pyridoxine (B6) pretreatment can completely or partially alleviate the effect of extreme temperature stress on seed germination and other physiological activities of alfalfa seedlings. Such treatment could be of importance for the establishment of alfalfa seedlings under temperature conditions colder or hotter than the optimum.Several parameters were studied in alfalfa seedlings primed before germination with 50 ppm ascorbic acid or 50 ppm pyridoxine for 6 h and then subjected to various temperatures (10, 15, 20, 25, 30, 35 and 40°C) for 7 days.The germination percentage of alfalfa seeds was negatively affected by extreme temperature. The vitamin treatments failed to alleviate the depressive effect of extreme temperature stress on seed germination. Extreme temperature also induced a reduction in the growth, total water content and respiration rate of alfalfa seedlings. Seed soaking in vitamins modified the stress-induced changes in respiration rate and growth criteria. Temperatures above or below the optimum stimulated the accumulation of soluble carbohydrates in alfalfa seedlings. Treatment with AsA or B6partially or completely retarded the stimulatory effects of extreme temperature on soluble carbohydrate accumulation in the seedlings except in the case of 40 °C, where a significant stimulation was detected. However, extreme temperature stress and its interactive effects with AsA or B6induced an inhibitory effect on the accumulation of free amino acids and soluble proteins in the test seedlings.

Modulation of Cholesterol and Copper Residue Levels in Muscles and Blood Serum of Finishing Broiler Chickens Fed Copper and Ascorbic Acid Supplements

To study the effect of Copper (Cu) and ascorbic acid supplements on modulation of cholesterol and copper residue content of chicken muscles and blood serum, two hundred and forty finishing Anak broiler chickens of mixed sexes were randomly allotted to four dietary treatment groups with four replication of fifteen birds each. The feeding period was 5 weeks. The response to copper and ascorbic acid were such that dietary supplementation with 250 ppm Cu alone resulted in 30 and 19% reduction in pectoralis major and biceps femoris muscles cholesterol respectively. Supplementation with 250 ppm Cu + 100 ppm Ascorbic acid resulted in 29 and 12% reduction in muscles cholesterol while inclusion of 100 ppm ascorbic acid alone brought about 4 and 10% reduction in the two muscles respectively. Serum cholesterol reduced by 28% and the addition 100 ppm ascorbic acid reduced this to 26%. Ascorbic acid (100 ppm) exerted 12% reduction in serum cholesterol. Ascorbic lowered the hypocholesterolemic potency of copper by about 1-7%. Combination of 100 ppm ascorbic and 250 ppm Cu slowed down rate of weight gain by 11% when compared with 250 ppm Cu alone as supplement, Supplementation with 100 ppm ascorbic alone improved carcass yield by 4% compared to 250 ppm Cu. Metalloprotein enzyme (AST and ALP) activities were significantly increased with supplementation. Cu residue was more in biceps femoris than pectoralis major muscle. Above 30% reduction in Cu residue was noticed with addition of ascorbic acid.

Effect of clipping feathers, dietary ascorbic acid supplementation and season on performance of laying chickens

Feathers may be problematic to chickens in thermoregulation during heat stress. This study was conducted to investigate the effect of clipping feathers, dietary ascorbic acid supplementation and season on performance of laying chickens. 180 ‘Isa Brown’ (IB) layers of about 30 weeks old were subjected to a 2×2×2 factorial combination of feather conditions (intact and clipping), dietary ascorbic acid supplementation (0 and 300 ppm) and season (early dry, ED and late dry, LD) during a trial using a factorial design. The birds were randomly allotted to 8 treatments consisting of treatment one (basal diet and intact feathers); treatment two (basal diet and clipped feathers); treatment three (basal diet supplemented with 300 ppm ascorbic acid and intact feathers) and treatment four (basal diet supplemented with 300 ppm ascorbic acid and clipped feathers) in both ED and LD seasons. Results showed that clipping feathers significantly improved (P 0.05) on HDP, WI, F/Doz., EW, and ESW. However, the effect of the interactions of the three factors were not significant (P>0.05) on FC, EM, EST and %ESW. Finally, clipping of feathers alone; secondly, dietary ascorbic acid supplementation at 300 ppm alone; and thirdly, a combination of the two, can be efficient in condition of heat stress. Key words: Feathers, ascorbic acid, season.

Growth and Feed Efficiency in Mangrove Red Snapper, (Lutjanus argentimaculatus Forsskal 1775) Fed Practical Diets Supplemented with L-ascorbyl-2-monophosphate-Mg

Growth and feed efficiency were determined in red snapper, Lutjanus argentimaculatus (Forsskal 1775), fed diets containing L-ascorbyl-2-monophosphate-Mg (AMP). Fish (13.39±0.08 g) were fed a practical diet without vitamin C supplement for four weeks then stocked in twelve 650-l tanks at 30 fish/tank and fed one of four practical diets containing AMP at 0, 60, 180, or 540 mg/kg dry diet for 17 weeks. Survival rates in all treatments were similar (88.9-98.9%). Fish fed the 0 or 540 ppm diets had inferior final average weights, protein efficiency ratios, and feed conversion ratios than fish fed the 60 or 80 ppm diets (p&lt;0.05). Growth of fish fed the 0 or 540 ppm diets slowed down on day 60 and fish fed the AMP-free diet exhibited clinical signs of vitamin C deficiency with a soft body and a significantly high (p&lt;0.05) hepatosomatic index. Ascorbic acid in brain and liver tissues rose with the level of dietary AMP. Fish fed the 540 ppm diet had significantly lower hematocrit (p&lt;0.05) than fish fed the 60 or 180 ppm diets. Histological analysis of the liver and kidney of fish fed the 180 and 540 ppm diets showed changes indicative of possible toxic effects. Based on growth, feed efficiency, tissue histology, and hematocrit level, AMP at 540 ppm is toxic to snapper. Thus, supplementation of 60 ppm AMP or its equivalent 26 ppm ascorbic acid in practical diets for red snapper promotes optimum growth and feed efficiency and prevents vitamin C deficiency symptoms.

تاثیر آنزیم آلفا آمیلاز و اسید اسکوربیک و بر خصوصیات رئولوژیکی خمیر و حجم مخصوص نان اشترودل

Effect of ascorbic acid and alpha amylase on rheological properties and specific volume of strudel bread was examined. Enzyme in three levels (0,300, 500 ppm) and ascorbic acid in three levels (0,100,200ppm) were used. Strudel was storaged in -17.c for 7 days. The samples thawed and proofed (Relative humidity 70%, temperature 40.c, time 45min) and then baked and specific volume was measured by seed displacement method. Rheological properties of dough were measured by brabender farinograph and extensograph. Rheological results indicated that ascorbic acid increase the dough strength and extensibility of dough .In addition, enzyme and ascorbic acid increase specific volume of strudels .The best samples produced by 200 ppm ascorbic acid and 500 ppm enzyme in combination . Keywords: Frozen dough – Strudel –Alpha amylase – Ascorbic acid

퉁퉁마디(Salicornia herbacea L.)에서 추출한 적자색 색소의 특성 및 안정성

퉁퉁마디의 적자색 색소의 안정성에 대한 pH, 당, 유기산, ascorbic acid, 아미노산, 식염 및 온도의 영향을 조사하였다. 퉁퉁마디 적자색 색소는 pH 4～6 범위에서 가장 안정하였으며, 저장기간에 따른 퉁퉁마디 적자색 색소의 잔존율은 다양한 당 첨가에 의해 대조구에 비해 높았다. 특히, 저장기간 10일 경과 후 0.5 M sucrose를 첨가한 시료구는 대조구에 비해 약 11.1% 가량 색소 잔존율이 높았으며 다음으로 fructose, maltose, glucose, galactose 순이었다. 또한, 유기산의 첨가로 종류와 농도에 관계없이 모두 대조구에 비해 저장기간 중 퉁퉁마디 적자색 색소의 잔존율을 감소시켰으며 특히, 유기산의 농도를 0.5 M로 가장 높게 처리한 시료구의 색소잔존율이 저장 10일 후 13.1～15.9%로 크게 감소하였다. 저장기간 10일 경과 후 ascorbic acid와 thio urea를 동시에 1,000 ppm씩 첨가한 경우 저장 10일 경과 색소의 잔존율이 48.4%로 대조구에 비해 약 23.1% 가량 높았다. 또한 아미노산 중에서는 aspartic acid를 50 mM 처리 시 색소 잔존율이 41.5%로 가장 높았으며 식염의 농도를 2.0 M 처리 시 색소의 잔존율이 31.6%로 대조구에 비해 높았다. 5℃와 25℃ 등 저온저장의 경우 색소의 안정성이 유지된 반면 저장온도가 상승함에 따라 색소의 안정성은 급격히 감소하였다.

염지제 종류와 혼합에 따른 기계발골 계육의 가공 특성과 저장성

기계발골 계육에 4종의 염지제(소금, 인산염, 아스코르빈산, 아질산염)을 각각 첨가, 혼합한 예비혼합된 기계발골 계육의 가공 및 저장 특성을 살펴보았다. 가공특성에서 소금의 첨가는 기계발골 계육의 보수력과 유화안정성을 향상시켰으며, 인산염의 첨가는 pH와 보수력을 증가시키는 효과가 나타났다. 아스코르빈산과 아질산염의 첨가는 기계발골 계육의 가공특성에서 pH, 보수력 및 색도에는 큰 영향을 나타내지 않았으나, 염용성 단백질의 용해도는 유의적으로 증가되었다. 저장특성에서는 아질산염과 아스코르빈산의 미생물 생육 억제과 항산화 효과에 의해 VBN과 TBA의 수치가 낮게 유지되는 경향을 나타냈다. 염지제들의 조합에 의한 혼합 처리에서는 소금과 인산염의 혼합 처리는 기계발골 계육의 염용성 단백질의 추출을 보수력을 향상시켰으며, 첨가수준을 달리한 소금, 인산염과 아스코르빈산의 혼합은 pH, 보수력을 증가시키는 효과가 나타났다. 소금, 인산 및, 아스코르빈산과 아질산염 등 4가지 염지제 혼합은 기계발골 계육의 가공특성에서 보수력의 증가뿐 아니라 육색에서 적색도(<TEX>$a^*$</TEX>값)가 높게 나타나 육색향상이 나타났으며, 또한 VBN과 TBA 수치를 낮게 유지할 수 있게 도움을 주었다. 이상의 결과에서 소금 1.5%, 인산염 0.5%, 아스코르빈산 500ppm, 아질산염 75ppm으로 예비혼합된 기계발골 계육은 기능적 가공특성과 저장특성이 향상된 계육가공제품의 원료육으로 적용이 가능함을 확인할 수 있었다. This study was conducted to determine the preblending effect of curing agents on the characteristics of mechanically deboned chicken meat (MDCM), including the pH, water-holding capacity (WHC), and stability under refrigeration conditions. MDCM was preblended with different curing agents [NaCl, 0.75 or 1.5%; sodium tripolyphosphate (STPP), 0.25 or 0.5%; ascorbic acid, 250 or 500 ppm; sodium nitrite, 75 or 150 ppm] and were stored at <TEX>$4^{\circ}C$</TEX> overnight. The preblending of NaCl was found to have improved the WHC and emulsion stability; STPP was found to have improved the pH, WHC, and emulsion stability; and ascorbic acid or sodium nitrite did not affect the pH, WHC, and emulsion stability. The addition of ascorbic acid or sodium nitrite, however, decreased the 2-thiobarbituric acid (TBA) and volatile basic nitrogen (VBN) values of the preblended MDCM through the antioxidizing properties. The mixing effects of different curing agents on MDCM were also evaluated with nine different conditions. Among the treatments, the mixture of NaCl and STPP improved the WHC and emulsion stability due to the increased solubility of salt-soluble protein in the preblended MDCM. The mixture of NaCl, STPP, and ascorbic acid increased the pH, WHC, and emulsion stability, but the mixture of NaCl, STPP, ascorbic acid, and sodium nitrite improved the WHC, emulsion stability, and redness of the surface color with improved storage stability due to the decreased VBN and TBA values. As a result, the mixture of 1.5% NaCl, 0.5% STPP, 500 ppm ascorbic acid, and 75 ppm sodium nitrite showed the best properties as curing agents for MDCM preblending.

EFFECT OF SOME FOLIAR ANTIOXIDANT TREATMENTS ON GROWTH AND PRODUCTIVITY OF COTTON GROWN IN UPPER EGYPT

The present study was carried out at the Experimental Farm of Mallawi Agric. Res. Station , Minia, in 2005 and 2006 seasons, to investigate the responses of cotton cultivar Giza 83 grown in upper Egypt to some foliar treatments of ascorbic acid (vitamin C) and citric acid , both were applied twice , at the start and peak of flowering, at the concentrations of 250 , 500 and 1000 ppm, using tap water as control. The obtained results could be summarized as follows : Foliar application of ascorbic acid (AA) at the concentration of 500 ppm resulted in significant increases in leaves content of chlorophyll a, b and carotenoids , plant height, number of open bolls /plant and seed cotton yield in both seasons, numbers of main stem nodes and fruiting branches /plant and boll weight in 2006 season, and it decreased fruit shedding % in 2005 season only in comparison with the control. Similar trend was obtained by 1000 ppm AA but the differences with the control were not always significant, and it significantly decreased earliness % in both seasons. The concentration of 250 ppm AA significantly increased leaves content of chlorophyll b and plant height in 2006 season only. Citric acid (CA) at the concentrations of 500 and 1000 ppm significantly increased leaves content of chlorophyll a , number of open bolls /plant in the two seasons , plant growth parameters and boll weight in 2006 season, and seed cotton yield in 2005 season. Only 1000 ppm CA significantly increased seed cotton yield and decreased fruit shedding % in the two seasons, while 250 ppm CA exerted no significant effects on all studied traits in both seasons. It could be concluded from results of this study that most used treatments of ascorbic acid and citric acid improved growth and fruiting performance of cotton plants grown under the naturally occurring climatic conditions of upper Egypt, however, the most consistently positive effects and the best results in general were obtained by spraying ascorbic acid at the concentration of 500 ppm or citric acid at the concentration of 1000 ppm.

Effects of trypsin‐hydrolyzed wheat gluten peptide on wheat flour dough

AbstractBACKGROUND: Gluten peptide was prepared by trypsin hydrolysis and characterized by high‐performance liquid chromatographic analysis. The effects on non‐frozen and frozen doughs of trypsin‐hydrolyzed gluten peptide (THGP) and its combination with ascorbic acid or KBrO3 were investigated.RESULTS: Molecular analysis of THGP showed a decrease in the high‐molecular‐weight and an increase in the low‐molecular‐weight sodium dodecyl sulfate‐soluble fractions, compared with those of control wheat gluten. The addition of 8% THGP decreased the mixing time and tolerance of the dough, both with and without ascorbic acid or KBrO3. However, the maximum resistance and extensibility of the rested dough containing 8% THGP, with and without ascorbic acid or KBrO3, were not significantly different from those of the control dough. The addition of 8% THGP significantly increased the loaf volume of bread baked from non‐frozen dough when combined with 60 ppm ascorbic acid or 30 ppm KBrO3, but it had a significant effect both with and without ascorbic acid or KBrO3 on frozen‐dough bread. A large difference in volume was observed between breads made with and without THGP at the oven‐spring, rather than at proofing.CONCLUSION: The addition of 8% THGP increased the loaf volume of bread made from freeze‐damaged dough and this effect increased when THGP was combined with 60 ppm ascorbic acid. Copyright © 2008 Society of Chemical Industry

Effect of Seasonal Temperatures and Ascorbic Acid Supplementation on Performance of Broiler Chickens Maintained in Closed and Open-Sided Houses

The efficacy of ascorbic acid in drinking water on performance of broiler chickens under closed and open-sided houses during hot (ambient temperature 36 C) and cool (ambient temperature 23 C) seasons o o were studied. The temperatures inside the poultry houses were 26 C (closed), 29 C (open-sided), 32 C o o o housed in each closed and open-sided environment for each season. Birds were maintained under 23 hrs light and 1 hr dark cycle and offered ad libitum access water and feed. Broilers in both houses were randomly subjected to four drinking water treatments (9 birds in each 6 replicates/treatment): 0, 100, 200 and 300 ppm ascorbic acid. Feed intake, body weight gain, feed conversion ratio and rectal temperatures were recorded weekly. Ascorbic acid supplementation at 200-300 ppm was associated with a reduction in rectal temperatures during the hot season. Open-sided house depressed body weight gain and feed conversion ratio (P < 0.05) during hot season. Compared to the control group, ascorbic acid improved feed intake, body weight gain and feed conversion ratio by 6%, 9% and 3% (cool season) and 8%, 11% and 5% (hot season). Birds supplemented with 200 ppm ascorbic acid had (P < 0.05) higher feed intake, body weight gain and feed conversion ratio than the control group during the cool season, while 300 ppm (P < 0.05) improved broiler performance including feed intake, body weight gain and feed conversion ratio during the hot season. Bird's rectal temperature was higher (P < 0.05) during hot season in open-sided house and (P < 0.05) reduced by supplementing 200-300 ppm ascorbic acid. This study demonstrated that seasonal temperatures had a significant effect on broiler performance in open-sided house. Supplementation of drinking water with 200-300 ppm ascorbic acid ameliorated broiler performance in open-sided housing at high ambient temperatures.

Concurrent administration of ascorbic acid enhances liver tumor-promoting activity of kojic acid in rats

We previously found that administration of ascorbic acid (AA) enhances the liver tumor-promoting activity of kojic acid (KA) in mice. To examine the reproducibility of these results in rats and the underlying mechanism of this effect, we employed a two-stage liver carcinogenesis model using male F344 rats. Two weeks after initiation with diethylnitrosamine (DEN), the animals received a diet containing 2% KA and drinking water with or without 5,000 ppm AA for a period of 7 weeks. A DEN-alone group was also established as a control. One week after the commencement of the administration, the animals were subjected to two-thirds partial hepatectomy. At the end of the experiment, the livers were analyzed immunohistochemically, and the mRNA expression level and extent of lipid peroxidation were measured. AA treatment enhanced the KA-induced tumor-promoting activity in terms of the number and area of liver cell foci that were positive for glutathione-S-transferase placental form. AA coadministration increased the number of hepatocytes positive for proliferating cell nuclear antigen and inversely decreased the number of TUNEL-positive cells. However, the increased level of thiobarbituric acid reactive substances resulting from KA treatment was suppressed by coadministration of AA. Gene expression analyses using low-density microarrays and real-time RT-PCR showed that coadministration of AA resulted in upregulation of genes related to cell proliferation and downregulation of those involved in apoptosis and/or cell cycle arrest. These results indicate that the concerted effects of AA on cell proliferation and apoptosis/cell cycle arrest probably through its antioxidant activity are involved in this enhancement.

Seed priming improves growth of nursery seedlings and yield of transplanted rice

An attempt to improve the performance of rice (Oryza sativa L.) nursery seedlings through seed priming and its effect on the yield after transplantation was made in a field trial. Priming tools employed during the investigation include pre-germination, hydropriming for 48 h, osmohardening with KCl and CaCl2 (ψs-1.25 MPa) for 24 h, vitamin priming with 10 ppm ascorbic acid for 48 h and seed hardening for 24 h. All the priming techniques resulted in improved germination speed and spread, seedling fresh and dry weight, root and shoot length, number of secondary roots, seedling nitrogen, total sugars and α-amylase activity. Osmohardening with CaCl2 resulted in the best performance as indicated by improved germination speed and spread, seedling vigour and starch metabolism, followed by hardening and osmohardening with KCl. However, improved starch metabolism in coarse rice was observed in osmohardening with KCl. Higher K and Ca contents were observed in seeds osmohardened with KCl and CaCl2, respectively. Maximum straw and kernel yield and harvest index were recorded from osmohardening with CaCl2 in fine and osmohardening with KCl in coarse rice. Increased number of secondary roots and α-amylase activity were accompanied with increased seedling nitrogen and reducing sugars, respectively.

Enhancement of Hepatocellular Proliferative Activity of Kojic Acid in Mice by a Simultaneous Administration of Ascorbic Acid

To examine the tumor modification activity of kojic acid (KA) by sodium ascorbic acid (AA), 5-week-old male ICR mice were administered intraperitoneally with N-diethylnitrosamine (DEN) as an initiation treatment. Two weeks after the initiation treatment, animals were fed basal diet containing 0 (Group 1: DEN alone) or 3% KA (Group 3: DEN+KA), drinking water containing 5,000 ppm AA (Group 2: DEN+AA) or 3% KA and 5,000 ppm AA (Group 4: DEN+KA+AA) for 6 weeks. One week after the administration of KA and/or AA, all mice were subjected to two-thirds partial hepatectomy. At the end of the experimental period, all surviving mice were sacrificed and removed the liver. The liver weights of the Groups 3 and 4 were significantly increased, and the number of proliferating cell nuclear antigen positive hepatocytes and the gene expressions of Ccnc, Ccnd1, Ercc and Cyp7a1 were significantly increased in the Group 4, as compared to the Group 1. These results of the present study suggest that AA enhances the hepatocellular proliferative activity of KA in mice.

Lipid oxidation and color change of salted pork patties

The purposes of this study were to explore the interaction of lipid oxidation and pigment oxidation in salted pork patties and to study the mutual relationship between lipid and pigment oxidation caused by replacing sodium chloride with potassium chloride at low salt levels. For fresh pork patties, a ∗ and b ∗ values decreased with the replacement of sodium chloride by potassium chloride. However, there were no significant differences of L ∗ values, pH values, total pigments and heme irons by replacement of NaCl with KCl; however, the replacement reduced 2-thiobarbituric acid reactive substances (TBARS). The addition of sodium tripolyphosphate, ascorbic acid and carnosine did not change a ∗ and b ∗ values of raw pork patties. However, raw pork patties with 0.25% sodium tripolyphosphate had significantly higher L ∗ value compared to other samples. The pH of raw pork patties with 0.5% carnosine was higher than those of other treatments. The pH of raw pork patties with 0.25% sodium tripolyphosphate was significantly higher than that of the control treatment with no antioxidant. Samples with 550 ppm ascorbic acid had significantly higher total pigment and heme iron than patties with 0.25% sodium tripolyphosphate. Although control treatment with no antioxidant had slightly higher TBARS values, these differences were not large enough to be significant.

Pengaruh Antioksidan sebagai Perlakuan Invigorasi Benih Sebelum Simpan terhadap Daya Simpan Benih Bunga Matahari (Helianthus annuus L.)

Oilly seeds, such as those of sunflower ( Helianthus annuus L.), have short storability (3-4 months in room condition) due to oxidative stress during storage. The objective of this research was to determine whether prestorage seed invigoration by antioxidants, could improve storability of sunflower seeds. The research was performed using fresh harvested seeds. Prestorage seed invigorations were conducted by matriconditioning with water or antioxidants solution i.e. 4.17% curcumin or 100 and 150 ppm ascorbic acid. The seeds were stored for four months at room condition (28-29 °C and 62-79% relative humidity). Observations were conducted monthly. Experiment was arranged in split plot design. The result showed that all prestorage seed invigoration treatments were not effective to enhance storability of sunflower seeds compared to control. Inefficiency exogenous antioxidants was probably due to highly endogenous antioxidants activity during storage. This was indicated by the slow deterioration rate of control seeds, or due to high concentration of curcumin which was actually potential to enhance storability of sunflower seeds. It is suggested that presowing treatment and midstorage treatment will enhance storability of sunflower seeds.

Retail Shelf‐Life of Pork Dipped in Organic Acid before Modified Atmosphere or Vacuum Packaging

ABSTRACTModified atmosphere packaging (MAP) is increasingly popular for meat, but raw, chilled pork in vacuum or anoxic environments has a purple color. The retail shelf‐life of pork chops dipped in 500 ppm ascorbic acid, 250 ppm citric acid, or no acid dip and stored at 1 °C before simulated retail display in MAP with gas exchange or air‐permeable packaging after vacuum pouch storage was determined. The 80% N2:20% CO2 in MAP was exchanged with 80% O2:20% CO2, and chops were removed from vacuum packages and overwrapped with permeable film (VP‐PVC) on the 7th day before simulated retail display at 4 °C. Shelf‐life traits were determined at 1, 7, 8, 10, 12, and 14 d postpackaging. The pH values changed with time, but returned to post‐dipped, prepackaged levels at the end of simulated retail storage. Weight loss of chops increased (P &lt; 0.05) in VP‐PVC compared with MAP. The a* values increased (P &lt; 0.05) and L* and b* values decreased during simulated retail display, with higher L*, a*, and b* color values for chops in MAP than VP‐PVC. Log numbers of psychrotrophic microorganisms were higher (P &lt; 0.05) on VP‐PVC samples than for chops in MAP on days 12 and 14. Psychrotrophic counts on ascorbic acid‐treated samples were decreased compared with citric acid or no dipping on pork during simulated retail display. Pork chops in MAP with gas exchange had lighter and redder color, increased weight retention, decreased psychrotrophic counts, and increased lipid oxidation compared with conventional vacuum and overwrap packaging systems.