Recently, traditional vegetables and fruits cultivated locally have been increasingly attracting the public’s attention, due to their superior palatability and health functions compared to vegetables and fruits commonly consumed in daily life. Some polyphenols are known to have preventative effects against many diseases and to influence the palatability and quality of foods. Thus, the characteristics of polyphenols contained in traditional vegetables and fruits grown mainly in Yamagata Prefecture were determined in relation to their health functions and food preferences. Major flavonoids identified in the petals of edible chrysanthemum flowers (Chrysanthemum×morifolium Ramat. forma esculentum Makino, cv Kotobuki) showed radical scavenging activities and liver injury-ameliorating effects, which were dependent on the chemical structure. Luteolin and luteolin 7-O-(6"-O-malonyl)-glucoside exhibited stronger radical scavenging activity than the other identified flavonoids. Pretreatment (oral administration) with luteolin or luteolin 7-O-(6"-O-malonyl)-glucoside strongly suppressed carbon tetrachloride (intraperitoneal injection) induced liver injury (increases in plasma aspartate aminotransferase and alanine aminotransferase activities) in mice. Main anthocyanins in 6 sweet cherry (Prunus avium L.) cultivars were identified and quantified to determine the relationship between anthocyanin and flavonoid (rutin) content with identical sugar moiety. Cyanidin 3-O-rutinoside, identified as a major anthocyanin in Japanese cherry cv Benisayaka, could be absorbed from the gastro-intestinal tract when orally administered with a malic acid solution, suggesting that the absorbed anthocyanins might be closely related to their physiological functions. It was also suggested that powdered Japanese cherry, which can be prepared from Japanese cherry juice by food processing, could be available as a raw material for cosmetics.
アミロース含量が異なる4品種の米飯を4°Cで0∼48時間まで冷蔵し,冷蔵後の飯を1粒ずつ0.1 mmの一定厚さに圧縮した圧縮米飯粒プレパラートを作成した.その色測定および顕微鏡撮影による透過光画像の解析より,米飯の老化を評価する新たな方法を検討した.
(1)圧縮米飯粒のL*はアミロース含量が低い米ほどL*も低く,いずれの品種も時間と共にL*が上昇し,冷蔵による米飯の状態変化が品種間の違いも含めて示された.
(2)圧縮米飯粒を顕微鏡で撮影した透過光画像の面積は冷蔵により小さくなり,見かけの密度は増大する傾向が認められた.
(3)圧縮米飯粒の透過光画像の輝度ヒストグラムには品種による特徴が表され,また冷蔵保存に伴い,低輝度側へシフトし,その時間は品種ごとに異なった.
(4)透過光画像の2値化画像(しきい値 : 輝度値130)より算出した圧縮米飯粒白色面積率α130および圧縮米飯粒L*値のいずれも,物性測定による硬さ,粘りとの相関が高く,米飯の物性との関連性が高いことが示された.また官能評価による老化感との相関係数は,白色面積率α130および圧縮米飯粒L*値のいずれも0.96と極めて高く,これらの解析は,品種のごとの特徴や米飯の老化を評価する新たな方法となることが示唆された.
新たな食品の品質評価法として注目されているメタボローム解析技術は,代謝物を網羅的に近い形で分析·解析することで,対象試料の状態を客観的に見ることができる手法である.そのため,この解析法は,カンキツなど生鮮食品の調理·加工操作による成分変化量を定量的に評価する優れた方法となり得るが,報告例は少ないのが現状である.そこで本研究では,広島県の特産品であるレモンを用いて加熱処理がレモン果汁の成分プロファイルに与える影響をGC/MSメタボローム解析技術に基づいて検討した.その結果,加熱処理はレモン果汁の成分プロファイルへ統計学的に意味のある変化を与えること.その変化は,糖類で顕著であることが明らかとなった.特にアラビノースおよびスクロースは,高温加熱の履歴を推定するマーカーとして有効であることが示唆された.アラビノースは,本研究で新たに見出したマーカーである.
Foodborne bacterial pathogens continue to pose a serious threat to public health and represent an economic burden in developed countries. These pathogens encounter many environmental stresses during food production, processing, storage, and distribution. Exposure to stress can induce various degrees of cellular injury depending on stress intensity and the physiological state of individual cells within the population. The injured cells may enter a non-culturable physiological state, in which the cells remain metabolically active, retain their pathogenic properties, and possess the ability to resuscitate under favorable conditions. These cells do not grow in conventional pre-enrichment media used for the detection of pathogenic bacteria in food and environmental samples, and may therefore go undetected during routine monitoring. These cells are presumed to be a significant potential risk for foodborne diseases. Thus, elucidating the molecular mechanisms underlying the induction and action of stress responses as well as resuscitation of the injured cells is essential for the development and implementation of more effective control measures. Moreover, such research will ultimately lead to more effective design and sequencing of processing steps, thereby preserving the nutritive value of food while ensuring maximum safety for the consumer.
The control of food poisoning associated with fish and fish products is challenging, even in the developed world. Injured cells of bacterial pathogens, generated by various stressors during food processing, are considered to be an important risk factor in food poisoning incidents. It is important to accumulate more knowledge on the physiology, genetics, and molecular biology of injured bacterial cells related to fish and fish products, and also to apply this knowledge to the development of new technologies. Here, we introduce recent advances in the physiology and genetics of Vibrio parahaemolyticus and Listeria monocytogenes and discuss future directions of the risk control of pathogens in fisheries.
Currently, injury of foodborne pathogen in agricultural environment is unclear. So, we observed survival of foodborne pathogens on common procedure for growing vegetable by cultivation on two types of agar medium that possess different selectivity. In case of Salmonella enterica serovar Infantis (SI) on the process of manure preparation, injury was estimated by cultivation on selective agar medium and resuscitation on non-selective agar medium. While in Listeria monocytogenes (LM) on cultivation environment of tomato, physiological changes were confirmed by salt content in agar medium. In manure environment, insufficient elevation of temperature in piled feedstock caused injured SI. LM survived for long term and part of these survived as injured LM in soil and on the surface of tomato fruits. It might be possible to estimate injured SI in actual condition of manure preparation by above procedure. On the contrary, there are practical difficulties for discriminating injured LM in actual agricultural environment by only salt sensitivity.