Non-enzymatic browning due to storage is reduced by using clarified lemon juice as acidifier in industrial-scale production of canned peach halves

Development of Araticum (Annona crassiflora Mart.) jams: evaluation of physical, microbiological, and sensorial stability in different packages

Araticum is an exotic fruit with unique sensory features and also high nutritional value characteristics. This study aimed to develop araticum jams with substitution of commercial pectin for passion fruit albedo, as well as to evaluate its physical, microbiological and sensorial stability during storage in polyethylene and polypropylene packages. Samples were analyzed at 25 and 35 °C for 130 days. During the storage the values of pH (3.5-4.9), titratable acidity (0.27-0.62%), color (L* 20.56-28.49, a* 1.32-7.03, and b* 1.32-9.29), chroma (1.86-11.65), hue (0.60-1.03), soluble solids (68-79.70 ºBrix), reducing sugars (12.60-60.30%), non-reducing sugars (6.22-56.19%), total sugars (55.30-96.30%), and carotenoids (0.21-1.27 mg.100 g-1) varied. The indicated shelf life was approximately 117 and 65 days for jams in polypropylene package, and 112 and 63 days for those kept in the polyethylene package, when the temperature of storage was 25 and 35 ºC, respectively. Araticum fruit is a good source for jams, that can contribute to the increased insertion of foods of better nutritional value in the consumer market.

Characterizing Maillard reaction kinetics and rheological changes in white chocolate over extended heating

Molten white chocolate held at high temperatures for extended periods of time undergoes thickening and nonenzymatic browning reactions. Lactose and milk proteins participate in Maillard browning, which occurs more rapidly at higher temperatures. Crystallization of amorphous lactose and high temperature contribute to rheological changes over heating. In the present study, five white chocolates of varied compositions were sampled over time at different temperatures. White chocolates containing amorphous lactose showed increases in complex viscosity, while chocolates with crystalline or no lactose showed no change in rheological properties. Maillard browning was measured through both colorimetry and spectrophotometric analysis of brown pigments. Both markers showed the greatest browning for Nonfat dry milk (NFDM)-containing systems. Chocolates containing no NFDM (milk protein isolate, MPI, or crystalline lactose) showed no change in absorbance after clarification, but some browning in colorimetry results, likely due to residual amorphous lactose in the MPI or increased mobility of lactose from crystals at high temperatures. The evolution of fluorescent intermediates was visualized using fluorescence spectroscopy, revealing that these intermediates were formed prior to colored end stage products and were consumed as the reaction approaches completion. An excess of lactose in the system meant reducing sugar declines were relatively small throughout. Kinetic models were created to determine the influence of chocolate composition and temperature on thickening as related to complex viscosity (first order) and browning via colorimetry and absorbance (pseudo-zero order). Both thickening rate and Maillard reaction rates were faster in chocolates with greater levels of amorphous lactose and when held at higher temperatures. PRACTICAL APPLICATION: So-called "golden chocolate" is white chocolate that has been held at warm temperatures for a period of time to undergo Maillard browning. However, thickening of the chocolate during heating can cause processing problems. In this study, viscosity changes are correlated with Maillard browning kinetics to help chocolate manufacturers find optimal conditions for creating new products.