Elucidation of potential relationship between endogenous proteases and key flavor substances in dry-cured pork coppa

Dry-cured meat products are considerably popular around the world due to unique flavor.Proteolysis is one of the enzymatic reactions from which flavor substances are derived,which is affected by endogenous proteases.The purpose aimed to reveal the potential relationship between endogenous proteases and key flavor substances in dry-cured pork coppa in this paper.The dynamic changes of endogenous proteases activity,free amino acids,and volatiles during dry-cured pork coppa processing were characterized.The results showed that 5 kinds of free amino acids,Glu,Lys,Val,Ala,and Leu,were identified as significant contributors to taste.Meanwhile,key volatiles,such as hexanal,nonanal,octanal,benzaldehyde,3-methyl butanoic acid,2-methyl propanoic acid,and ethyl octanoate,greatly contributed to the flavor characteristics of dry-cured pork coppa.Further partial correlation analysis was performed to better elucidate the relationship among parameters.The results revealed that close relationship between endogenous proteases and key substances.RAP not only significantly affected the accumulation of key active-amino acids,but also affected the accumulation of ethyl octanoate,2,3-pentanedione,and 2,3-octanedione by regulating the accumulation of octanoic acid and Leu.In addition,cathepsin B and D,DPP II,DPP IV and RAP notably affected accumulation of hexanal.

Evaluation and selection of yeasts as potential aroma enhancers for the production of dry-cured ham

Yeasts play a critical role in the flavor formation of dry-cured ham.In this study,41 yeast isolates from the dry-cured ham at different processing stages were evaluated for their technological properties.Debaryomyces hansenii was the most dominant yeast and has been detected at each phase of dry-cured ham,followed by Candida zeylanoides which was mainly detected in salting phase.Yarrowia bubula and Yarrowia alimentaria were found at the first two-phase of dry-cured ham.All isolates of yeast showed enzymatic activities against milk protein and tributyrin,while only 4 strains displayed proteolytic activity on meat protein.Yeast strains were grown in a meat model medium and volatile compounds were identified.The result showed that inoculated yeast strains could promote the production of volatiles and there were significant differences among strains.D.hansenii S25 showed the highest production of volatile compounds,followed by the strain C.zeylanoides C4.D.hansenii S25 was the highest producer of alcohols showing the highest production of benzeneethanol and 3-(methylthio)-1-propanol.Based on OAV and PLS analysis,D.hansenii S25 was strongly correlated with overall flavor and key volatile compounds of dry-cured ham,which could be selected as potential starter cultures.

What Writings Match Poet＇s Suffering

The author found the text and poem writing had not always been correspondent to his personal experience through observation and reading. The poets really meant that their own poems could not express his suffering when he said he had been afraid that he could not match his suffering. People often think the rich experieuce is the key to the depth of writing, but the truth is not like that. The author concluded that the content of poem shall keep certain gap with the ethic meaning through research on the experience and writing of the great poets and give an ontological questioning and then he can embody common humanity and emotion without blank teaching. A poet shall be in face of the difficulty of writing and learn to handle with the challenge of difficulty, and then the difficulty can be transferred into skill of writing,

Recalling the War in China： The Dahoufang Project in Chongqing and the Restoration of a Legacy

This article presents a rare inside view of a unique project currently underway in China to study and preserve the memory of possibly the single most seminal event in Chinese modern history, the War of Resistance against Japan （1937-45）. The article introduces a multi-faceted program to preserve the wartime cultural heritage; the work is ongoing in the thriving western metropolis of Chongqing, once China＇s bomb-torn wartime capital and international Allied command center. It describes how, seven decades after World War II, scholars, cultural workers, government experts, and artists in China are joining hands in an unprecedented, all-encompassing project to record, restore, and recount the extraordinary legacy of China＇s War of Resistance in its local, as well as national and global contexts.