摘要:

In this, the third part of a series of four reviews, the factors ‐which control the shelf‐life of long and intermediate life dairy products are discussed. Two distinct types of product degradation are addressed. Firstly, the degradative potential of heat‐resistant lipase, protease and phospholipase, derived from psychrotrophic bacteria commonly found in refrigerated milk, is examined. Secondly, the chemical composition of milk is reviewed and lipid oxidation, calcium induced aggregation of milk protein and Maillard reaction are identified as likely routes to product spoilage. The relative importance of these reactions to specific products will be discussed in the final part of this series of art

ISSN:1364-727X    

DOI:10.1111/j.1471-0307.1996.tb02493.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

Feta cheese was made from ewe's milk using three different levels of starter (0.20, 0.50 and 0.75%) and two draining times (6 and 20 h). Cheese made with addition of 0.75% starter had a lower pH and moisture content than the cheeses made with 0.20 and 0.50% starter. With the increase in starter level there was also an increase in cheese fat content, although the fat in dry matter remained almost constant. The lower level of starter resulted in cheese with lower protein content, while other cheese components were not significantly affected by the starter levels used. The yield of cheese made with addition of 0.75% starter was significantly lower than the yield of cheeses made with the other levels. Also, the yield of cheeses made with 6 h drainage was greater than the yield of cheeses made with 20 h drainage. In general, the organoleptic and rheological properties of cheeses were not affected by the three levels of starter used for feta cheese manufacture.

ISSN:1364-727X    

DOI:10.1111/j.1471-0307.1996.tb02494.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

Whey produced during the manufacture of labneh was supplemented with yeast extract (10 g/1), and then fortified with lactose, treated with β‐galactosidase or fermented with Lactobacillus helveticus, prior to inoculation with free living cells of Propionibacterium freudenreichii ssp shermanii or Propionibacterium acidipropionici or cells immobilized in aliginate beads. Under anaerobic batch conditions, fermentation of the whey with Lb helveticus followed by P acidipropionici (free cell system) for 2.5 days at 32°C gave a broth with 5.9 g/l of propionic acid and 2.4 gll of acetic acid, while immobilized cells of the same organisms gave a broth with 11.0 gll propionic acid and 3.2 g/l acetic acid over 4 days. These latter values were the maximum levels recorded with any of the treatments, and it is suggested that such yields might make recovery economically feasible in certain countr

ISSN:1364-727X    

DOI:10.1111/j.1471-0307.1996.tb02495.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

This paper deals with two packaging related problems occasionally encountered in the handling and storage of 25 kg sacks of dairy powder. One is caused by the production of low bulk density powder and the other is caused by excessive air entrapment in the sack. To gain a better insight into the problem, dairy powder manufacturers were visited and consultations were made with bagging machine manufacturers. The production of low bulk density powder is predominantly due to a low particle density, and the major contributory factors are total solids content, composition, state of protein denaturation of the feedstock and drier characteristics. Factors that affect excessive air entrapment in a sack are transport and storage of powder prior to bagging, powder properties and entrapment of headspace air. Possibilities for side‐stepping the problem include the use of perforated liners or the development of semipermeable liners that are more permeable to air than conventional liner

ISSN:1364-727X    

DOI:10.1111/j.1471-0307.1996.tb02496.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

Book reviewed in this article:Guide to Quality Management Systems for the Food Industry. By Ralph Early.Cheesemaking in Scotland–A History. By J Smith (Scientific editor A Tamime

ISSN:1364-727X    

DOI:10.1111/j.1471-0307.1996.tb02497.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

The microbiological quality assurance (MQA) of edible table spreads, including milk fat, margarine type and blended products having fat contents in the range 5–80% by weight, in new product development is considered in relation to the sampling and monitoring of marker microorganisms, hazard and risk analyses, challenge testing, preservative efficacy testing and the modelling of the growth of spoilage micro‐organisms in compartmentalized food emulsion systems. It is shown that the use of ingredient and process technologies to implement ecological principles of MQA plays a major role in the development of safe, wholesome and shelf stable edible table spre

ISSN:1364-727X    

DOI:10.1111/j.1471-0307.1996.tb02498.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY