Mid-infrared-assisted freeze drying (MIR-FD) of Jerusalem artichoke cubes were attempted and their performance (processing time, energy consumption, color, water activity, hardness and rehydration) was compared with single-stage freeze dried (FD, control) samples. Two mathematical models could be used to describe the drying curves. It was aimed to improve the drying parameters and product quality of MIR-FD dried material. The effect of mid-infrared pre-drying (MIR) on drying rates of Jerusalem artichoke cubes was examined at different infrared intensity (3 and 6 kW/m 22 ). The values of drying rate considerably changed when the infrared intensity and pre-drying time was increased from 3 to 6 kW/m 22 and from 4 to 5 min. The MIR-FD hybrid drying mode took 15-40% lesser time compared to FD dried samples. Therefore, MIR-FD drying is an effective and economical method. MIR application had a significant (P < 0.05) effect on the color of the final product. The FD resulted in a product with significantly lower firmness and slightly higher water uptake (P < 0.05) than samples dried in the MIR-FD. Hybrid drying gave better results -all of the quality parameters -over MIR alone. PRACTICAL APPLICATIONSThe Jerusalem artichoke (Helianthus tuberosus L) is available in fresh and processed forms (powder, chips and soft drinks), the Jerusalem artichoke is rich in inulin, sugars, protein, macro and micro elements. Freeze-and mid-infrared drying have been industrially applied in the drying of foodstuffs and pharmaceutical products. The aim of this article is to examine the effectiveness of freeze drying (FD) enhanced with two-stage mid-infrared-freeze drying. The application of the mid-infrared-freeze drying (MIR-FD) produces a fast drying rate and higher drying quality. Our research work confirmed that MIR-FD is a good alternative instead of the FD. The development of new drying possibility for vegetables with good physical, chemical properties may be of interest in regard to the market supply (food supplement, functional food, etc.).

This article provides results of an experimental investigation of hybrid- (MIR-FD), mid-infrared- (MIR) and freeze drying (FD) on the drying characteristics, energy consumption and quality parameters of pear. Rehydration ratio, color, texture, water activity, phenolic content and antioxidant activity were measured to evaluate the quality of dried pear products. Mid-infrared-freeze drying (MIR-FD) had the higher drying rate, which reduced the drying time by 14.3–42.9 % compared with FD method. Two empirical models were chosen to fit the drying curves and the models had the suitable R2 and RMSE values. Temperature characteristics of MIR and MIR-FD dried pear were determined in terms of interior temperature variation. The MIR-FD pear had darker color, better rehydration capacity, similar water activity, lower hardness (except of MIR-FD70°C) and highest content of chemical composition than single stage of FD products. Above all, the MIR50-60°C-FD was suggested as the best drying method for pear in this study.

The nutritive value, the microbiological safety of oilseed cake (OSC) obtained from naked pumpkin seed (PuC), sunflower seed (SC), yellow linseed (LC), and walnut (WnC), and their impact on wheat flour (WF) dough and bread sensory characteristics at 5% and 10% addition ratio were investigated. The OSCs had high protein (34-50%), fat (8-15%), total dietary fibre (23-36%) content and high energy value (383-444 kcal/100 g)). The OSC samples with a minimal exception fulfilled the requirements of feed legislation in force. An increased water absorption, dough development time, and reduced elasticity were observed probably due to the enhanced fiber and protein content. Dough stability increased with WnC, and decreased with PuC or SC addition. Enrichment provided the appearance of a brown bread for WnC, of a half-brown bread for LC. PuC gave an unusual look. The appearance of OSC fortified bread similar to daily bread, was an advantage resulting the 1 st rank for 10% WnC bread and the 2 nd one for 10% LC bread (P=0.05). The studied OSCs are suitable for food enrichment, however, in case of PuC and SC fortified flour blends, hydrocolloid application is recommended. Our data suggest that the newly developed fortified breads could be a valuable source for healthy nutrition.

Cold-pressing residue of walnut kernel (WKR) and brown linseed (BLR) was applied in wheat flour blends at 100:0, 95:5 and 90:10 ratios, of which enriched breads were baked, then stored for 3 days at ambient temperature. Colour parameters and firmness of bread crumb were measured daily. Bavarian rye-bread (BR) and wholemeal multigrain bread (WMMG) were used as competitive, marketable breads for comparing tests.Effect of oil-seed pressing residue on bread colour and texture 119 The studied oil-seed pressing residues (OSRs) resulted brown colour with different characteristics, depending both on the type of OSR and in comparison with marketed breads, too. The type and the ratio of OSR applied had no influence on the varying of crumb texture (P = 0.107). WKR and BLR enrichment provided stable texture for breads with a 3-day shelf-life, independently from their addition ratio. BLR resulted in softer crumb than WKR; however, this difference was considered to be negligible (P = 0.128). The WKR-and BLR-enriched breads stayed significantly softer at the end of storage time than the marketed breads (P = 0.000). Our results indicate that competitive bakery goods can be produced using oil-seed pressing residue/wheat flour blends.

We evaluated the microbiological safety, the short-term storability, and the macronutrients of oil seed cake (OSC) obtained from walnut (WnC), linseed (LC), and sunflower seed with hull (SC). The OSCs had 3.6-5.8% moisture content, 0.50-0.60 water activity (a w ), 29.9-39.4% protein, 15.5-23.6% fat, and 36.6-48.0% dietary fibre content. The grinded OSCs could be stored in opaque plastic bags for 4 months at temperatures of 4 °C, 14 °C, and 25 °C. Total colony count of mesophilic microorganisms depending on oxygen demand and spore-forming ability, and faecal indicator microorganisms were determined during a 4-month storage term at 4 °C, 14 °C, and 25 °C using traditional culturing methods. The OSCs were free from sulphite-reducing Clostridia and coliforms, including Escherichia coli. Data were analyzed statistically by multifactor analysis of variance. Ascending order of the average contamination of the three products (log 10 CFU g -1 ) was aerobic sporogenic bacteria (2.39), fungal count (2.51), total aerobic microbe count (3.00), anerobic sporogenic bacteria (3.75), and total anaerobic microbe count (4.23). As for the average microbial count, WnC was the least (2.73 log 10 CFU g -1) and LC was the highest (3.53 log 10 CFU g -1 ) contaminated material. Regarding the variation of microbial contamination during storage, temperature was indifferent (P=0.191), while storage time (P=0.0033) and the product type were influential (P=0.000).