Longer Storage Periods Research Articles

Effects of Antioxidants on Rapeseed Oil Oxidation in an Artificial Digestion Model Analyzed by UHPLC–ESI–MS

A normal diet contains large quantities of oxidized fatty acids, glycerolipids, cholesterol, and their cytotoxic degradation products because many foods in the diet are fried, heated, or otherwise processed and consumed often after long periods of storage. There is also evidence that the acid medium of the stomach promotes lipid peroxidation and that the gastrointestinal tract is a major site of antioxidant action, as demonstrated by various colorimetric methods. The identity and yields of specific products of lipid transformation have seldom been determined. The present study describes the molecular species profiles of all major gastrointestinal lipids formed during digestion of autoxidized rapeseed oil in an artificial digestion model in the presence of L-ascorbic acid, 6-palmitoyl-O-L-ascorbic acid, 3,5-di-tert-butyl-4-hydroxytoluene (BHT), DL-α-tocopherol, and DL-α-tocopheryl acetate. Differences in oxidized lipid profiles were detected in the samples digested in the presence of different antioxidants, but none of them could prevent the formation of oxidized lipids or promote their degradation in a gastric digestion model. The lack of effect is attributed to the inappropriate nature of the gastrointestinal medium for the antioxidant activity of these vitamins and BHT. A fast ultrahigh performance liquid chromatographic-electrospray ionization-mass spectrometric method was developed for the analysis of lipolysis products, including epoxy, hydroperoxy, and hydroxy fatty acids, and acylglycerols, utilizing lithium as ionization enhancer.

THE GENETIC POTENCY OF PLANTAIN AGUNG SEMERU VARIETY FROM LUMAJANG REGENCY EAST JAVA INDONESIA

Lumajang regency is one of the banana production centre in East Java having high- diversity of banana germ plasm. There are 33 cultivars of banana germ plasm in the regency, consist of eaten ripe and plantain. One of uniqe plantain used as the symbol of Lumajang regency is plantain Agung Semeru variety, the local superior variety of this regency. This variety can grow well at 450 – 650 m above sea level. The uniqueness of banana Agung Semeru variety can be seen by the number of sucker per cluster (only 1 – 2 suckers per cluster), the size of the finger (33 – 36 cm long and 19 cm around) and the number of hand per bunch (only 1 – 2 hand per bunch). Other characteristics of the variety are the thickness of fruit skin, the long period of fruit storage (3 – 4 weeks after harvesting) and the sweetness of fruit flesh. Even though the skin changes from yellow to black, the flesh still can be consumed, because it doesn’t become soft. This variety also resistant to the Sigatoka disease compared to other plantain cultivars.

Effect of sample storage time on detection of hybridization signals in Checkerboard DNA–DNA hybridization

Long-term sample storage can affect the intensity of the hybridization signals provided by molecular diagnostic methods that use chemiluminescent detection. The aim of this study was to evaluate the effect of different storage times on the hybridization signals of 13 bacterial species detected by the Checkerboard DNA-DNA hybridization method using whole-genomic DNA probes. Ninety-six subgingival biofilm samples were collected from 36 healthy subjects, and the intensity of hybridization signals was evaluated at 4 different time periods: (1) immediately after collecting (n= 24) and (2) after storage at -20°C for 6 months (n= 24), (3) for 12 months (n= 24), and (4) for 24 months (n= 24). The intensity of hybridization signals obtained from groups 1 and 2 were significantly higher than in the other groups (p< 0.001). No differences were found between groups 1 and 2 (p> 0.05). The Checkerboard DNA-DNA hybridization method was suitable to detect hybridization signals from all groups evaluated, and the intensity of signals decreased significantly after long periods of sample storage.

Viability of Blackbrush seed (Coleogyne ramosissima Torr. [Rosaceae]): Following Long-Term Storage

Blackbrush ( Coleogyne ramosissima Torr. [Rosaceae]) is a landscape-dominant shrub that occurs in an ecotonal band between warm and cold deserts of the western US. This vegetation type is at considerable risk from stand-replacing wildfires due to the introduction of exotic annual grasses. Because blackbrush does not form a persistent seedbank, restoration following fire requires that seed produced in mast years be collected and stored for future use. This study examined germination of 32 collections of blackbrush seed following 12 to 27 y of storage at room temperature. Germination and emergence of multiple seed collections taken from across the geographic and elevational range of this species revealed that blackbrush seed can be maintained in storage for long periods of time. Average germination remained high ( 80%) for the first 10 to 12 y of storage. Emergence was low, however, when germination percentage fell below 50%, indicating that production from older seed may require that germinants be planted in a greenhouse to produce plants for later outplanting to the field. Based on current climate predictions, blackbrush will likely migrate upward in elevation and (or) latitude as conditions become warmer and drier. Seed for restoration would best be used at the blackbrush upper elevational range or higher.

유근피 추출물을 첨가한 식혜의 저장성 및 관능특성

In this study, 0, 20, 40, 60, 80, and 100% L. nonglutinous and glutinous sikhe were added to L. extracts for 15 days at , and for seven days at , to examine the extracts` storage properties and sensory characteristics. The results are as follows: (1) On the changes of pH and acidity during storage of L. nonglutinous and glutinous sikhe, both of them showed lower pH values with lower additive L. extract contents. The pH value continuously decreased with a longer storage period, and the acidity was higher with a lower concentration of L. extract. (2) The total microbial cell count during storage of L. nonglutinous and glutinous sikhe at was 4.6-5.0 log CFU/g at 0 day. The sikhe to which L. extract was not added increased to 8.8-9.0 log CFU/g on the seventh storage day, while the sikhye to which 80 and 100% L. extracts were added were 7.8 and 6.9 logCFU/g, respectively. Thus, the total cell count was lower with a higher additive content of L. extract. The total cell count of the sikhe to which 0-60% L. extracts reached the maximum value on the seventh storage day and did not show any change thereafter. The total cell count of the sikhe to which 80 and 100% L. extracts were added, however, reached the maximum value on the 10th to 13th storage days, thus showing that the storage period was increased by L. At , the total cell count was 4.6-5.0 log CFU/g on 0 day and continuously increased during the storage period. It had increased to 8.9-9.5 log CFU/g on the seventh storage day, and no differences were shown according to the additive content of L. extract. (3) On the sensory characteristics of L. nonglutinous and glutinous sikhe, the L. nonglutinous sikhe to which 20% L. extract was added showed the highest overall-acceptability value (), whereas the L. glutinous sikhe to which 40% L. extract was added showed the highest overall-acceptability value (). The sikhe to which 20 and 40% L. extracts were added showed significantly high taste, flavor, sweetness, and overall-preference values (p

냉장 중 연근 및 연잎분말을 첨가한 돈육 패티의 품질변화

본 연구는 연근 및 연잎분말의 첨가가 돈육 패티의 저장 중 품질에 미치는 영향을 규명하고자 하였다. 돈육 패티는 돈육 88%, 대두유 5%, 냉수 5%, 소금 2%를 배합하여 제조한 대조군(T0), 여기에 연잎분말 0.5% 첨가한 것(T1), 연근분말 0.25% 및 연잎분말 0.25% 첨가한 것(T2), 그리고 연잎분말 0.5% 첨가한 것(T3) 등 네 종류의 돈육 패티를 제조하였다. 이들은 저장 중 색깔, 보수력, 가열감량, 두께 증가율, 직경 감소율, 기계적 조직감, pH, VBN 함량 및 TBARS값을 측정하였다. 저장 중 <TEX>$a^*$</TEX>값은 감소하는 경향이었다(p<0.05). T3의 <TEX>$L^*$</TEX>및 <TEX>$a^*$</TEX>값이 가장 낮았으며, <TEX>$b^*$</TEX>값은 T2 및 T3가 T0 및 T1보다 높았다(p<0.05). 보수력은 저장 중 유의하게 낮았으며(p<0.05), 시료들 사이에 보수력, 가열감량, 두께 증가율 및 직경 감소율의 차이는 없었다. 저장기간이 경과하면서 경도 및 저작성은 증가하였으며, 탄성은 감소하였다(p<0.05). pH는 저장 중 높아지는 경향이었다(p<0.05). VBN 함량은 저장 중 변화가 없었으며, 시료들 사이에도 유의한 차이가 없었다. TBARS값은 저장 중 유의하게 증가하여 저장 9일째 T0, T1, T2 및 T3가 각각 4.57, 1.85, 0.43 및 0.41 mg MA/kg을 나타내었다(p<0.05). 이상의 결과, 연근과 연잎분말을 병행 하거나 연잎분말을 단독으로 사용할 경우 기능성 육제품의 제조가 가능할 것으로 여겨진다. This study was carried out to investigate the effect of lotus root and leaf powder on the quality characteristics of pork patty stored at <TEX>$3^{\circ}C$</TEX> for 9 days. The pork patties were of four types: nothing added(control, T0), 0.5% lotus root powder added (T1), 0.25% lotus root and 0.25% lotus leaf powder added (T2), and 0.5% lotus leaf powder added (T3). The <TEX>$a^*$</TEX> value tended to decrease with longer storage period (p<0.05). The <TEX>$L^*$</TEX> and <TEX>$a^*$</TEX> value of T3 had the lowest value among the samples, the <TEX>$b^*$</TEX> value T2 and T3 were higher than those of T0 and T1 (p<0.05). Water holding capacity decreased with longer storage period (p<0.05), the water holding capacity, cooking loss, increase rate of thickness and decrease rate of diameter were not significantly different among the samples. Hardness and chewiness increased and springiness decreased with longer storage period (p<0.05). The pH creased with longer storage period (p<0.05), but the VBN content not changed during storage. The TBARS values increased with longer storage period (p<0.05), and those of T0, T1, T2 and T3 were 4.57, 1.85, 0.43 and 0.41 mg MA/kg, respectively, after 9 days of the storage. The result suggest that the addition of lotus root and leaf powder at the same time, or addition of lotus leaf powder can be applied to pork patty to its functionality.

가열 돈육 patty의 품질특성에 미치는 연근 및 연잎분말 첨가 효과

This study was carried out to investigate the effects of adding lotus root and leaf powder on the quality characteristics of cooked pork patties. The patties were of four types: unadulterated (control, T0), 0.5% lotus root powder (T1), 0.25% lotus root and 0.25% lotus leaf powder (T2), and 0.5% lotus leaf powder (T3). We found that the moisture content was highest in T1 group, and that the protein and fat contents were lowest in T1 (p<0.05). The ash content was lowest in T0 (p<0.05). The cooking yield and moisture retention level were not significantly different among the samples, but fat retention was the highest in T3 (p<0.05). The hardness, springiness, cohesiveness and chewiness were also highest in T3, and the gumminess was lowest in T0 (p<0.05). The <TEX>$L^*$</TEX> values tended to increase with longer storage periods, and that of T0 was the highest after nine days of the storage (p<0.05). By contrast, the <TEX>$a^*$</TEX> values decreased with longer storage periods (p<0.05), with that of T3 being the lowest (p<0.05) during storage periods. The water holding capacity decreased with longer storage periods, and that of T1 was the highest (p<0.05) during storage periods. The pH of T1 decreased, and those of T2 and T3 increased with a longer storage period (p<0.05). TBARS values increased with a longer storage period, and those of T0, T1, T2 and T3 were 8.69, 2.95, 0.88 and 0.55 mg/kg, respectively, after nine days of storage (p<0.05).

Survival, Acid and Bile Tolerance, and Surface Hydrophobicity of Microencapsulated B. animalis ssp. lactis Bb12 during Storage at Room Temperature

Survival, acid and bile tolerance, and surface hydrophobicity of microencapsulated Bifidobacterium animalis ssp. lactis Bb12 were studied during storage at room temperature (25 °C) at low water activity (0.07, 0.1, and 0.2). Two types of alginate-based systems were prepared with and without mannitol as microencapsulant of B. animalis ssp. lactis Bb12. Formation of gel beads containing cells was achieved by dropping each emulsion into CaCl(2) solution; then, the beads were freeze dried. Survival, acid tolerance during 2-h exposure in de Man, Rogosa, Sharpe (MRS) broth at pH 2.0, bile tolerance during 8-h exposure in MRS broth containing taurocholic acid at pH 5.8, and retention of surface hydrophobicity were determined after freeze drying and during storage. The result showed that neither alginate nor alginate-mannitol formulation was effective in protecting B. animalis ssp. lactis Bb12 during freezing and freeze drying. The viability in alginate-mannitol and alginate formulations after freeze drying was 6.61 and 6.34 log CFU/g, respectively. Storage at low a(w) improved survival, acid tolerance, bile tolerance, and surface hydrophobicity retention of microencapsulated B. animalis ssp. lactis Bb12 when compared with controlled storage in an aluminum foil (with a(w) of 0.38 and 0.40 for alginate-mannitol and alginate formulations, respectively). Alginate mannitol was more effective than the alginate system during a short period of storage, but its effectiveness decreased during a long period of storage (80% survival at 10 wk). Nevertheless, storage of microencapsulated B. animalis ssp. lactis Bb12 in an aluminum foil without a(w) adjustment during 10 wk at room temperature was not effective (survival was 64% to 65%).

The HPLC/DAD Fingerprints and Chemometric Analysis of Flavonoid Extracts from the Selected Sage (Salvia) Species

The results of spectrophotometric and HPLC/DAD analysis are discussed, and a comparison is made of selectively extracted flavonoid fractions derived from twenty six sage species belonging to the Salvia genus. The sage samples were harvested in the vegetation seasons 2007, 2008, and 2009. It was a goal of this study to find out which species contain the highest yields of flavonoids (recognized for their free-radical-scavenging activity), as those with the highest yields could be applied in official medicine. It was spectrophotometrically established that the four sage species can be recognized for their highest flavonoid levels, while the HPLC/DAD analysis pointed out to the four other species. The source of the discrepancy between the two evaluation approaches was discussed. Moreover, the HPLC/DAD fingerprints of the flavonoid fraction underwent a chemometric pre-treatment, and then the purified fingerprints were analyzed by means of Principal Component Analysis (PCA) for the differences in the harvesting period. A difference was revealed between the herbs harvested in the 2007 season, and those harvested in 2008 and 2009. The main source of this difference could be the seasonal weather variation and the relatively longest storage period with the plants harvested in 2007.

PRODUKSI DAN FORMULASI BIOINSEKTISIDA DARI PROPAGUL AKTIF JAMUR BEAUVERIA BASSANIA

Beauveria bassiana is a well known entomopathogenic fungus that has been widely used for biocontrol of many economically important pest of crops. Production technology for massive production of bioinsecticide B. bassiana still using liquid fermentation. Product formulation is the critical stage for producing bioinsecticide B. bassiana, since its success indicator is the contain of viable propagules in the final product after long period of storage. The aim of this study is to assess the optimal production of biomass and formulation of bioinsecticide B. bassiana. Result showed that the best production technology of bioinsecticide B. bassiana is by liquid fermentation, as an innovative method aimed to reduce the production cost. Assessment of formulation of bioinsecticide B. bassiana showed that formulation using simple raw materials to make a pasta without filler is the best choice to be further developed.

The changes of etheric oil content in powdered garlic during storage in different packaging materials

The etheric oil components in garlic are proven to have numerous positive effects on human health, and powdered garlic has long been widely used in both the food industry and private households. In order to prolong the stability of etheric oil components, different combinations of packaging materials are used for the storage of powdered garlic. Since the quality of dehydrated powder depends on the packaging used, the investigation was aimed to determine the effects of packaging material types on etheric oil content in industrially powdered garlic over the storage period. Powdered samples were analysed immediately after production and during long periods of storage (after 30, 90, 120, 180 and 270 days). The investigations were focused on the correlation between packaging materials performances (light, water vapour and air permeability), and the changes of etheric oil and moisture content in powdered garlic. In order to describe the changes in etheric oil content during time, as well as to predict changes in packed powdered garlic, a statistical procedure was applied for all examined packaging materials and curve fitting data were estimated (the least square approach).

Changes of physicochemical quality, phenolics and vitamin C content in hardy kiwifruit ( Actinidia arguta and its hybrid) during storage

The effect of storage and the stage of maturity of hardy kiwifruits on the physicochemical quality, phenolics (TPC) and ascorbic acid content (AAC), as well as antioxidant activity (AA) were studied in this work. The phenolic compounds in hardy kiwifruits were separated and characterized by HPLC. The investigation was carried out on the two cultivars of Actinidia arguta – ‘Weiki’, ‘74-49’ and the hybrid of A. arguta and Actinidia purpurea (‘D14’). Fruit firmness rapidly decreased and the soluble solid content (SSC) increased for all cultivars during the first 14 days of storage at 1 °C. The AAC and TPC in vine ripe fruits were similar to the ones of the fruits of storage harvest maturity (8–10% SSC). AA content depended on the clone and either decreased during storage or remained almost unchanged. There was an increase in TPC after 7 days of keeping the fruits in a cold store chamber at the temperature 1 °C, but a longer period of storage caused a decrease in these compounds. AA (at harvest for storage purposes) was higher than that of vine ripe fruits and the ability to absorb free radicals slightly decreased during storage. There was a strong correlation between AAC, TPC and AA. That means that phenolics and vitamin C affect the antioxidant activity of hardy kiwifruits.

Resistência ao cisalhamento de braquetes metálicos utilizando sistema adesivo autocondicionante

OBJETIVO: avaliar a resistência ao cisalhamento de braquetes metálicos colados com sistema autocondicionante utilizado imediatamente e após 2, 5 e 9 dias depois da ativação e armazenagem. MÉTODOS: utilizaram-se 64 dentes bovinos divididos igualmente em quatro grupos e devidamente preparados para receber a colagem dos braquetes. Em T1, realizou-se a ativação de 7 blisters de adesivos autocondicionantes (de acordo com as normas do fabricante) e procedeu-se à colagem imediata apenas dos braquetes do grupo I. Os adesivos ativados foram, então, armazenados à temperatura de 4ºC e reutilizados em períodos de 2 dias (T2), 5 dias (T3) e 9 dias (T4) para a colagem dos braquetes dos grupos II, III e IV, respectivamente. RESULTADOS: não se observou diferença estatística quando comparados os valores médios de tensão para resistência ao cisalhamento entre os grupos I, II e III. Entretanto, diferença estatística foi encontrada quando esses valores foram comparados aos do grupo IV. CONCLUSÃO: o armazenamento do adesivo autocondicionante depois de ativado, à temperatura média de 4ºC, por até 5 dias, parece não afetar os resultados quanto às tensões de resistência ao cisalhamento; novos estudos são necessários para avaliação das demais características do material quando de sua utilização por período de tempo prolongado após sua ativação.

EFFECT OF PRETREATMENTS FOR RETAINING TOTAL CAROTENOIDS IN DRIED AND STORED ORANGE-FLESHED-SWEET POTATO CHIPS

Various dipping pretreatments have been investigated for orange-fleshed sweet potato (OFSP) to retain carotenoids after drying and subsequent storage. Effects of blanching,sodiummetabisulfite(0.5or1%),acids(ascorbicacid[1%]orcitricacid [0.5%]) or salt (1%), either singly or as mixtures, were tested on dried OFSP chips thatwerestoredforupto6monthsinambientconditions.Overall,therewasapositiveeffectof dippingontotalcarotenoidcontentafterdryingcomparedwithcontrol (P < 0.05).Aslightimprovementincarotenoidcontentwasobservedduringthefirst month of storage with ascorbic acid,sodium metabisulfite,and mixtures of sodium metabisulfiteandcitricacid,orascorbicacidandsaltpretreatments,butthesehigher levels were not maintained over longer storage periods (4‐6 months). The general lackof improvementwasbelievedtoresultfromtheleachinganddegradationof the chemicals during storage.

Influence of l-cysteine, oxygen and relative humidity upon survival throughout storage of probiotic bacteria in whey protein-based microcapsules

The survival rates of Lactobacilus acidophilus Ki, Lactobacillus paracasei L26 and Bifidobacterium animalis BB-12 were studied after whey protein microencapsulation via spray-drying, with or without l-cysteine-HCl, and storage up to 6 months at 5 °C and 22 °C, with variation in relative air humidity and oxygen levels. Lb. paracasei L26 was the least susceptible to storage conditions: above 10 6 cfu g −1 were recorded by 180 d at 22 °C, irrespective of relative humidity, and the presence/absence of oxygen and l-cysteine. Higher relative humidity, higher temperature and longer storage periods were deleterious to survival of both B. animalis BB-12 and Lb. acidophilus Ki; the effect of l-cysteine-HCl was dependent on the probiotic strain. The effect of overhead oxygen was not significant upon any probiotic strain studied. Whey protein microcapsules containing l-cysteine-HCl protected probiotic cultures from simulated gastrointestinal conditions.

Influence of temperature and edible coating on the physical and chemical parameters and sensory acceptance of fresh-cut organic carrots Influencia de la temperatura y cobertura comestible en los parámetros físicos y químicos y aceptación sensorial de las zanahorias cortadas frescas

The effects of storage temperature and edible coating on the microbiological, physical, and chemical properties and sensory acceptance of fresh-cut organic carrots (Daucus Carota L. cv. Brasília) were investigated. The samples were diced, sanitized in sodium hypochlorite, and the excess water was drained in a centrifuge. The dry samples were then immersed in a 2% gelatin solution, packed in multilayer polypropylene bags and sealed. The coated and non-coated samples were stored at 1 °C, 5 °C, and 10 °C for 15 days. The results showed that the weight loss was below 0.43% for all samples. The weight loss increased with temperature, and a significant effect was observed. The carrots' texture decreased with higher storage temperatures and longer storage periods for all samples, being the same behavior observed for color. Sensory analyses showed best responses for samples stored at 1 °C, for both treatments with and without coating. Fue analizado el efecto de la variación de la temperatura y el tiempo de almacenamiento sobre las propiedades microbiológicas, físicas, químicas y sensoriales, de zanahorias orgánicas, mínimamente procesadas (Daucus Carota L. cv. Brasília) con cobertura comestible. Las muestras fueron cortadas, sanitizadas en una solución hipoclorhídrica y el exceso de agua retirado por centrifugación. Las muestras drenadas fueron inmersas en una solución de gelatina al 2% y después empaquetadas en bolsas de polipropileno de múltiples capas. Muestras con y sin recubrimiento fueron almacenadas en temperaturas de 1 °C, 5 °C, y 10 °C durante quince días. Los resultados demostraron que en todas las muestras, la pérdida de peso fue inferior a 0.43%. Esta pérdida de peso tuvo un aumento significativo y proporcional con la temperatura. La textura de las zanahorias, en términos de dureza, se redujo con el aumento de la temperatura y el tiempo de almacenado, para todas las muestras. El mismo comportamiento fue observado en lo que se refiere al color. Los resultados del análisis sensorial mostraron una mejor aceptación para las muestras almacenadas a1 °C, sean ellas con o sin recubrimiento.

THE IMPORTANCE OF SUBSAMPLE PREPARATION PRACTICES IN THE ANALYSIS OF CRUDE OILS

There have been many subsample preparation practices proposed to reduce sources of error in analyses of crude oils. Optimal subsample preparation allows keeping the degree of representativity of the final aliquot going into the laboratory analyzer. The objective of this work was to discuss some experiences in order to understand the importance of sampling practices to obtain representative subsamples of crude oils and petroleum products, and measurements with minimized uncertainty whenever possible. Specific practices, whose effectiveness was tested by experiments, are discussed in this work. The analysis of variance showed that the subsamples should not be used in vapor pressure tests unless in case of interlaboratory crosscheck, and have to be considered as the first test from the bottle subsample. Sometimes long periods of crude oils samples storage are necessary for a complete evaluation, but because of the effect of this storage time it was observed a trend in the reducing of acidity and sulfur content.

Cloning and optimization of induction conditions for mature PsaA (pneumococcal surface adhesin A) expression in Escherichia coli and recombinant protein stability during long-term storage

The gene corresponding to mature PsaA from Streptococcus pneumoniae serotype 14 was cloned into a plasmid with kanamycin resistance and without a purification tag in Escherichia coli to express high levels of the recombinant protein for large-scale production as a potential vaccine candidate or as a carrier for polysaccharide conjugation at Bio-Manguinhos/Fiocruz. The evaluation of induction conditions (IPTG concentration, temperature and time) in E. coli was accomplished by experimental design techniques to enhance the expression level of mature recombinant PsaA (rPsaA). The optimization of induction process conditions led us to perform the recombinant protein induction at 25 °C for 16 h, with 0.1 mM IPTG in Terrific Broth medium. At these conditions, the level of mature rPsaA expression obtained in E. coli BL21 (DE3) Star by pET28a induction with IPTG was in the range of 0.8 g/L of culture medium, with a 10-fold lower concentration of inducer than usually employed, which contributes to a less expensive process. Mature rPsaA expressed in E. coli BL21 (DE3) Star accounted for approximately 30–35% of the total protein. rPsaA purification by ion exchange allowed the production of high-purity recombinant protein without fusion tags. The results presented in this work confirm that the purified recombinant protein maintains its stability and integrity for long periods of time in various storage conditions (temperatures of 4 or −70 °C using different cryoprotectors) and for at least 3 years at 4 or −70 °C in PBS. The conformation of the stored protein was confirmed using circular dichroism. Mature rPsaA antigenicity was proven by anti-rPsaA mouse serum recognition through western blot analysis, and no protein degradation was detected after long periods of storage.

속단추출물의 첨가로 인한 양념 돈육의 품질특성 및 저장성 향상

속단 주정추출물의 총 폴리페놀 및 총 플라보노이드 함량은 각각 57.32±2.30 ㎍/㎎, 21.44±2.52 ㎍/㎎이고, FRAP 소거활성은 0.26 ㎜ol Fe²?/g으로 나타났으며, 속단추출물은 또한 높은 DPPH 소거능 및 gram 양성균인 Staphylococcus aureus에 대해 항균 활성을 보였다. 속단 주정추출물을 첨가한 양념소스에서도 시료첨가량이 증가할수록 DPPH 소거능이 증가하였다. 또한 돈육을 속단 주정추출물을 첨가한 양념돈육을 제조하여 4℃에서 21일간 저장하면서 품질특성을 검토한 결과, 속단추출물 첨가 양념돈육은 0.1% BHA 처리구와 유사하게 대조구에 비해 총 세균 수 및 지방산패도가 감소되었으며 대장균은 검출되지 않았다. 관능평가에서도 0.5% 속단 주정추출물을 첨가하면 높은 다즙성, 풍미, 전반적인 기호도에서 높은 평가를 받았다. 따라서 항산화능 및 항균 활성을 가진 속단추출물은 양념돈육에서 저장성 및 품질 특성의 개선에 도움을 줄 수 있는 소재로 여겨진다.

Volatile Fatty acids and Alcohols Production during Anaerobic Storage of Dairy Manure

Production of volatile fatty acids (VFAs), alcohols, and several other compounds in batch-stored dairy manure was experimentally studied. Test conditions included three initial total solids (TS) contents of dairy manure (2%, 4%, and 9%) and three storage temperatures (15°C, 25°C, and 35°C). Under each set of test conditions, the concentrations of methanol, ethanol, and VFAs in the manure and the amount and composition of biogas produced were measured over a one-month period. Results showed that the higher TS content of the manure resulted in more VFAs and less biogas production. Temperature had a positive effect on methanogenic activity, especially in the manure with 2% TS. At 35°C, the total VFAs reached 16,500 and 23,000 mg COD L-1 in the manures with 4% and 9% TS, respectively. Acetic acid represented over 42% of the total VFAs as COD. The highest methanol and ethanol concentrations (30 and 230 mg L-1, respectively) were found in the manure with 9% TS stored at 35°C. A mathematical model was applied to calculate the generation and emission rates and cumulative emissions of acetic acid from dairy manure stored under different temperatures and wind velocity conditions. Modeling results for a 1,000-cow dairy farm located in Davis, California, showed that the cumulative acetic acid emissions from a lagoon receiving the manure with 2% TS were about 4.8 and 11.2 g per cow per month under winter and summer conditions, respectively. More research is underway to calibrate and validate the emission model over a longer storage period.