Yoko Kinoshita

Stability Tests of Household Margarine

To know a shelf-life of margarine, eleven kinds of household margarine were preserved at 5°C and the change of POV, AV and vitamin A content were investigated, together with sensual check. Besides, unwrapped samples of seven kinds were left in refrigerator and taking out for one hour every day, as a usual handling condition. In addition, as abnormal storage condition, similar samples were exposed to fluorescent light or left under sunlight.Results obtained were as follows:1) In the shelf-life test, only one sample of high linoleic type developed odor slightly after 12 months. All samples under usual handling condition were not developed any odor for 3 months. However, under fluorescent light, samples of high linoleic type developed abnormal odor within 2 to 5 days, and all samples under sunlight showed same tendency within 5 hours to 2 days.2) POV and AV were hardly changed during the shelf-life test and vitamin A was remained 97.8% (average) after 12 months.3) Under usual handling condition, POV was hardly changed and average of vitamin A remained was 99.0% after 3 months. However, under sunlight, POV increased to 45.94-4. 32 (x: 17.56) and average of vitamin A remained was 78.9% after 5 days. In this case, samples of high linoleic type tended to deteriorate more than those of common soft and hard type margarines. But, AVs were hardly changed in either condition.

General Properties and Nutritional Evaluations of Recent Domestic Margarine

家庭用マーガリンのソフト型13種, カートン包装ハード型9種, 簡易包装ハード型2種, 計24種の脂肪酸組成, ステロールおよびトコフェロールを測定し, これらの一般的特徴を調査するとともに脂肪の質を表わす諸指標による栄養的評価について検討した。その結果は次のとおりである。1) 脂肪酸組成およびステロール組成比の結果から簡易包装ハード型を除く全試料は植物油脂のみを原料として製造されたものであり, またサフラワー油と表示された5試料 (アベナステロール) およびとうもろこし油と表示された3試料 (総ステロール量, シトおよびスチグマステロール比) からそれぞれの特徴を示すステロール分析結果を得た。2) ソフト型およびカートン包装ハード型のトランス酸量は平均14.49および19.18%を示し, 米国産マーガリンよりいずれも低かった。とくにソフト型の2試料からはまったく検出されなかった。3) リノール酸を含むC18: 2ではソフト, カートン包装および簡易包装ハード型の各平均値は38.21, 20.61および10.85%であり, とくにソフト型には45%以上含まれる高リノール型のものが4試料見いだされた。4) 総トコフェロール量はほとんどの試料に 20～50mg/100g含まれ, 抗酸化の目的には最適の濃度と一致した。同族体別には一般にα-よりγ-のほうが多かったが, サフラワー油表示のソフト型5試料ではα-が最も多かった。とくに高リノール型の試料には20mg/100g以上のα-が含まれていた。5) 各試料を高リノールおよび一般ソフト型, ハード型および簡易包装ハード型に分類して栄養的に評価すると, 高リノール型は多価不飽和酸の給源であり, しかもそれにある程度対応したビタミンEも含有され, さらに血中コレステロール低下効果のあることを示した。

Stability of Shortening for Frying or Spraying

AOM test and oven test (50°C, 10 weeks) were carried out with 29 samples of shortening for frying and spraying, and the correlation between the stability and the composition of shortening was examined.Even though there was hardly recognized any changes in acid value by oven test with all samples tested, but changes of peroxide vatue separated into two groups, the one showed no change and the other changed rapidly. As the results of AOM test, it was found that there were 9 samples which required more than 100hrs. and 6 samples which required less than 50hrs. In general, samples compounded with coconut oil system and those with low degree of unsaturation tended to prolon, g the AOM time.There were correlations between iodine value or content of unsaturated fatty acids and the AOM time or the peroxide value obtained by the oven test for 10 weeks, but the correlation coefficients with the AOM time was higher than those with the peroxide value.