Shrinkage in canned mushrooms treated with xanthan gum as a pre-blanch soak treatment

Vacuum treating freshly harvested mushrooms with a 1% xanthan gum solution (XVT) containing 0.25% sodium metabisulphite (SMBS) prior to blanching and canning gave a lower shrinkage value than for corresponding samples vacuum treated with water, or those canned by conventional means or the 3S process. A combination of chill storage (2-4°C) for 1-3 days coupled with 1% XVT was found best and gave even lower total canning losses (chill storage loss + blanch loss + retort loss); these were 6% lower than in the 3S process and 11.5% lower than for mushrooms canned by the conventional procedure. These data suggest that xanthan gum has considerable potential for reducing shrinkage in canned mushrooms. The XVT canned samples had an excellent colour and an acceptable texture. Further storage tests over a 9 month period with xanthan treated canned mushrooms showed than an SMBS level of 0.1% in the pre-blanch soak solution maintained an excellent colour in the canned product. No in-can mushroom shrinkage took place during the 9 month storage test.     

FUNDAMENTAL RHEOLOGY AND QUALITY CHARACTERISTICS OF SOUS‐VIDE PROCESSED APPLE PUREES CONTAINING APPLE OR BLACKCURRANT POMACE INCLUSIONS

ABSTRACT

The effect of pomace type and level of inclusion on the quality and rheological characteristics of sous‐vide processed apple puree (Bramley's Seedling) was evaluated. Purees containing apple (Shampion freeze‐dried, Shampion, Ariwa) and blackcurrant pomaces, at inclusion levels of 0, 2.5 and 5% w/w, were processed by sous‐vide (P₉₀ > 10 min). Reductions in L* color values (P < 0.001) were observed in pomace type and inclusion level. Shampion pomace had the highest (P < 0.001) sensory acceptability (3.63) of the pomaces (control 4.21). Both pomace type and increasing pomace inclusions influenced (P < 0.001) rheological properties. This was supported by texture analysis, i.e., increase (P < 0.001) in extruded force with increasing pomace inclusion. The best performing pomace (Shampion) was included in sous‐vide purees at eight levels (0, 2.5, 5, 6, 7.5, 9, 10 and 12.5%, w/w). The highest pomace inclusion gave the firmest purees without affecting color. Sensory data indicated that purees with up to 7.5% w/w pomace were acceptable.

PRACTICAL APPLICATIONS

Research has concluded that consumption of fruits and vegetables in Europe is substantially below World Health Organization guidelines (<400–600 g/day). As fruits are a significant source of fiber, it is important that their intake is maintained as part of a healthy diet. Providing a choice of fresh and minimally processed fruit products is the key to increasing consumption. Following the success of ready‐meals, the expectation for similar retail success exists for ready‐desserts. This study focused on assessing the effect of pomace inclusions on the quality parameters of sous‐vide processed Bramley's Seedling apple purees. The development of these products would benefit both consumers (health) and processors (cost‐effective way of adding value) alike. Inclusions of pomaces had significant effects on color, sensory and rheological parameters of apple purees. These outcomes may be of benefit to the food industry to develop better products.     

A review of: “Actes du Colloque ELABORATION ET JUSTIFICATION DES MODELES”, edited by P. Delattre and M. Thellier. Maloine S.A., Paris, 1979, 2 volumes, 748 pp.

This paper utilizes trapezoidal rule together with Genetic Algorithm (GA) to convert a continuous-time system with input and state delays to an equivalent discrete-time one. A new method has been proposed to construct the hybrid control of sampled-data system with state and input delays via digital redesign which transforms the control law of a continuous-time system with state and input delays into an equivalent one of a sampled-data system so that the states of the digitally controlled sampled-data system closely match those of the originally well-designed continuous-time system for a relatively longer sampling period. An example is given to demonstrate that the proposed digital redesign is superior to the existing ones under a longer sampling period.     

PARACONSISTENT LOGIC (in Italian), by Nicola Grana. Lofredo Editore,Naples, 1983. 134 pp.

Modified Reconstructibility Analysis (MRA), a novel decomposition within the framework of set-theoretic (crisp possibilistic) reconstructibility analysis, is presented. It is shown that in some cases, while three-variable NPN-classified Boolean functions are not decomposable using Conventional Reconstructibility Analysis (CRA), they are decomposable using MRA. Also, it is shown that whenever a decomposition of three-variable NPN-classified Boolean functions exists in both MRA and CRA, MRA yields simpler or equal complexity decompositions. A comparison of the corresponding complexities for Ashenhurst-Curtis decompositions and MRA is also presented. While both AC and MRA decompose some but not all NPN-classes, MRA decomposes more classes, and consequently more Boolean functions. MRA for many-valued functions is also presented, and algorithms using two different methods (intersection and union) are given. A many-valued case is presented where CRA fails to decompose but MRA decomposes.