Open Access. Powered by Scholars. Published by Universities.®

Food Science Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 3 of 3

Full-Text Articles in Food Science

Effects Of Tempering And Fat Crystalization Behaviours On Microstructure, Mechanical Properties And Appearance In Dark Chocolate Systems., Emmanuel Ohene Afoakwa, Alistaiar Paterson, Mark Fowler, Joselio Vieira Jun 2008

Effects Of Tempering And Fat Crystalization Behaviours On Microstructure, Mechanical Properties And Appearance In Dark Chocolate Systems., Emmanuel Ohene Afoakwa, Alistaiar Paterson, Mark Fowler, Joselio Vieira

Professor Emmanuel Ohene Afoakwa

Fat crystallisation behaviours in dark chocolates from varying particle size distribution (PSD) (D90 of 18, 25, 35 and 50 µm) was studied, yielding products from different temper regimes (optimal temper, over-temper and under-temper), and their effects on mechanical properties and appearance evaluated. Microstructures of derived products were determined using stereoscopic binocular microscopy. Wide variations in mechanical properties and appearance were noted in products from different particle size and temper regimes. Particle size (PS) was inversely related with texture and colour, with the greatest effects noted in hardness, stickiness and lightness at all temper regimes. Over-tempering caused significant increases in product …


Use Of Neutral Electrolysed Water (Ew) For Quality Maintenance And Shelf-Life Extension Of Minimally Processed Lettuce, Daniel Rico, Ana Belen Martin-Diana, Catherine Barry-Ryan, Jesus Maria Frias, Gary Henehan, José Barat Jan 2008

Use Of Neutral Electrolysed Water (Ew) For Quality Maintenance And Shelf-Life Extension Of Minimally Processed Lettuce, Daniel Rico, Ana Belen Martin-Diana, Catherine Barry-Ryan, Jesus Maria Frias, Gary Henehan, José Barat

Articles

Experiments were conducted to determine the effectiveness of different treatments based on the use of neutral electrolysed water (EW) on fresh-cut lettuce. EW was diluted to obtain different free chlorine concentrations (120, 60 and 12 ppm) and compared with standard washing treatment of 120 ppm chlorine solution. Shelf-life quality and safety markers were studied at the beginning and at the end of the 7-day storage at 4 ºC. The use of EW decreased the respiration rate of the samples which might be related with the observed reduction in microbial spoilage. The use of EW also increased the activity of a …


Optimisation Of Steamer Jet-Injection To Extend The Shelf Life Of Fresh-Cut Lettuce, Daniel Rico, Ana Belen Martin-Diana, Catherine Barry-Ryan, Gary Henehan, J. Barat, Jesus Maria Frias Jan 2008

Optimisation Of Steamer Jet-Injection To Extend The Shelf Life Of Fresh-Cut Lettuce, Daniel Rico, Ana Belen Martin-Diana, Catherine Barry-Ryan, Gary Henehan, J. Barat, Jesus Maria Frias

Articles

Optimisation of short time blanching (steaming) was investigated using response surface methodology by analysing quality and microbial and nutritional markers over the shelflife of packaged fresh-cut lettuce. Steamer treatment time (5–10 s) and storage (1–10 days) were used as independent factors in order to optimise the process. Longer treatments (>10 s) were not feasible because of extensive damage caused to lettuce tissue. Significantly (p < 0.05) higher values of luminosity (L*), greenness (−a*) and sensory panel scores (fresh appearance, general acceptability and absence of browning) were obtained with samples treated for longer times with the steamer. Activity of browning-related enzymes present in photosynthetic tissue decreased in all the cases, however, longer treatment time (7.5–10 s) was needed with vascular tissues to reduce to similar activity values. These differences could be explained by the variation in tissue thickness. The longest steam treatment (10 s) reduced and maintained significantly (p < 0.05) lower mesophilic load than shorter treatments (5–8.5 s). However, significant (p < 0.05) decreases in vitamin C and carotenoids were observed in samples treated with longer treatments. Steamer treatment of 10 s could be considered the optimum time for maintaining the shelflife (mainly texture and browning) of fresh-cut lettuce for 7–10 days in optimum conditions.