Course Of Ripening Research Articles

Studies on Volatiles of Banana Fruits, Esterification of Added iso-amyl Alcohol in Pulp Disks

Mechanism of esterification of alcohol using banana pulp disks was investigated. The alcohols, mainly iso-amyl, alcohl were added to the disks in the form of solution (infiltration method) or vapor. Conversion of isoamyl alcohol to acetate was not observed with mature-green banana while it occurred sharply in the course of ripening of fruits. The conversion was supposed to be enzymatic reaction, and some inhibitors (monoiodoacetate, sodium azide), N2 atmosphere, soaking in water depressed the rate of esterification considerably. When banana pulp was homogenized, the reaction stopped and, on the contrary, iso-amyl acetate added was hydrolized rapidly. The addition of ATP and CoA did not show any effect on esterifiication, while the addition of acetic acid immediatly increased iso-amyl acetate production. Rapid esterification of added alcohol vapors (C3 iso-C4, C4, iso-C5, C5) took place on pulp disks.

Relationship between the ripening of harvested fruits and the respiratory pattern (I)

Relation between the ripening and the drift of carbon dioxide production of harvested fruits was investigated to reconsider the meaning of respiratory pattern. The materials used were as follows: strawberries(Donner)and peaches(Hakuto, white flesh variety) as the species of which respiratory pattern has not been necessarily clear, tomatoes (Fukuju No. 2) as a typical climacteric class, and Satsuma oranges (Sugiyama, Citrus unshiu) as a non-climacteric class. The respiratory activities of pulp (or peel) homogenates of these fruits were measured to investigate the changes of respiratory mechanisms during ripening.1. It was proposed from the results obtained in the present and preceding experiments that the respiratory pattern of the harvested fruits should be classified in three types, not in two types of usual classification as climacteric and non-climacteric. It is as follows: (1) Respiratory rates gradually decrease through ripening process…… the gradual decrease type. (2) Respiratory rates increase temporarily, and full-ripe occurs after the peak of respiration…… the temporary rise type. (3) Maximum rate of respiration is shown from full-ripe to over-ripe stages…… the late peak type.According to the classification mentioned above, citrus fruits belong to the gradual decrease type, and the temporary rise type corresponds to the typical climacteric class including fruits such as tomatoes, bananas, pears, avocados, etc. Japanese persimmons, strawberries, and peaches belong to the late peak type. In the fruits of the late peak type, as a characterististics of the type, the relation between the time of respiratory maximum and the degree of ripeness is not clear as compared with temporary rise type, and the peak height of respiration varies remarkably among individual fruits.2. Regardless of respiratory pattern, it was seemed that qualitative change of respiration took place in the course of ripening. The increasing effect of cofactors(NAD, AMP, ATP, cytochrome c) on the oxygen uptake in strawberry homogenates changed remarkably during ripening. In the tissue slices and the cell-free extract of Satsuma orange peel, the effect of organic acids application on oxygen uptake changed during yellowing of the fruits which had been harvested at almost-green stage. At immature stage, the addition of malic and succinic acids increased respiration greatly, but citric acid had no effect. At yellow-colored stage, the effect of the former two acids diminished, but citric acid showed the effect in a high degree.

The Spequence of Formation of Oil in Castor Seeds. I-II. I. Changes in Oil in the Course of Ripening of Castor Seed.

ヒマ子実の成熟にともなう油脂変化について研究を行いつぎのことを明らかにした。(1) 子実中の含油量が急激に増加を来すのは開花後40日以後であるがそれ以前の含有油のケン化価には上下の変動が現われる。(2) 初期の含有油は水素添加を行うとガスの放出が見られる。(3) 含有油の赤外吸収スペクトルによれば純ヒマ種子油と同様な吸収が現われるのは開花後30日頃で, 40日頃にはすでに完成しており, それ以後の含油量の増加にともなう変化は見られい。(4) 開花後60日の含有油中にはステアロジリシノレインと推定される結晶が多量に含まれる。

(196)菜種子実の成熟および発芽にともなう油脂変化について

(196)菜種子実の成熟および発芽にともなう油脂変化について

微生物代謝に及ぼす食塩の影響に関する研究-III

This report is a part of investigations that have been made to clear the mechanism of salt antiseptication. 1) As far as the influence of dryness does not affect, the fish muscle which is saturated with salt to its own water content is able to preserve sufficiently. But, in case drying method is different the aspect of putrefaction differs from each other. 2) Optimum temperature and salt concentration in preparation of “Ika-shiokara” are 20°C and 20% respectively. 3) It is infered that the characteristic flavor of “Ika-shiokara” is not attrributable to the variation of amino acids in the course of ripening.

13. Studies in the Ripening of Cheddar Cheese I. A Method of Following the Course of Ripening of Cheddar Cheese

A Study of the chemical changes involved in the ripening of Cheddar cheese becomes largely a study of protein degradation. The result of the breakdown of the casein through the combined effect of rennin, milk enzymes and proteolytic bacteria is to furnish water-soluble decomposition products which increase in amount as the ripening progresses. In consequence a method used by many workers in the past to follow the course of ripening was to determine at intervals the percentage of soluble nitrogen present in the cheese. It must be remembered, however, that the decomposition products which make up this soluble nitrogen factor comprise different compounds such as caseoses, peptones, polypeptides, amino acids and ammonia, which are of decreasing molecular complexity in the order named. All these compounds are soluble in water to varying extents and, therefore, a determination of the soluble nitrogen merely gives an estimate of the sum total of the nitrogen which they represent, and gives no information as to the way in which it is distributed amongst the different types.