Breadsticks Flavoured with Olives and Onions: One-Year Shelf Life

Abstract

In this work, we compared breadsticks (known as Treccine) flavoured with onions and olives and prepared with olive pomace oil (OPO) or with extra virgin olive oil (EVOO). The effect on one-year shelf life was also studied. The following physical, chemical and sensory analyses were conducted on the breadsticks: water activity, moisture content, colour, texture and sensory analysis (appearance, colour, flavour, taste, texture and overall acceptability). For the oil extracted from the Treccine, we determined acidity, peroxide value, spectrophotometric parameters, ABTS and DPPH assay on the hydrolitic fraction, DPPH on the lipid fraction, and fatty acids. We detected a progressive deterioration in the quality of breadsticks with a decrease in shelf life after 4-6 months in relation to each studied parameter. In the analysed breadsticks, water activity was 0.342 (OPO recipe) and 0.387 (EVOO recipe) after one-year storage; in the same storage period, the moisture content was 6.34 times (OPO) and 5.32 times (EVOO) greater. Appearance and colour were the only two sensory parameters which, after 12 months, remained above or equal to five stated as the minimum quality value. In the extracted oil, Free acidity increased from 0.35 to 0.56% (OPO) and from 0.71 to 0.98% (EVOO); Peroxide value ranged between 6.10 and 102.89 meq/kg oil (OPO) and between 4.41 and 20.91 meq/kg oil (EVOO). K232 was highest in OPO (2.43-3.70) and lowest in EVOO (1.76-2.92), K268 was 1.32-1.580 (OPO recipe) and 0.570-0.640 (EVOO recipe). Treccine prepared with extra virgin olive oil showed better biological properties and longer shelf life.

Keywords: Treccine; baked products; breadstick; extra virgin olive oil; lipid oxidation; olive pomace oil; packaging; shelf life.

Figure 1

The breadsticks Treccine, flavoured with olives and onions.

Figure 2

(a) Water activity of Treccine prepared with olive pomace oil and with extra virgin olive oil during one-year shelf life; (b) moisture of Treccine prepared with olive pomace oil and with extra virgin olive oil during one-year shelf life. The green line and green letters are related to Treccine prepared with EVOO. The black line and black letters are related to Treccine prepared with OPO. Values with different letters with the same colour are significantly different: *** p < 0.001.

Figure 3

Hardness of Treccine prepared with olive pomace oil and with extra virgin olive oil during one-year shelf life. The green line and green letters are related to Treccine prepared with EVOO. The black line and black letters are related to Treccine prepared with OPO. Values with different letters with the same colour are significantly different: *** p < 0.001; * p < 0.05.

Figure 4

Colour by instrumental analysis of Treccine prepared with olive pomace oil and with extra virgin olive oil during one-year shelf life. (a) Lightness; (b) red/green; (c) yellow/blue; (d) Chroma; (e) Whitness index. The green line and green letters are related to Treccine prepared with EVOO. The black line and black letters are related to Treccine prepared with OPO. Values with different letters with the same colour are significantly different *** p < 0.001; ** p < 0.01.

Figure 4

Colour by instrumental analysis of Treccine prepared with olive pomace oil and with extra virgin olive oil during one-year shelf life. (a) Lightness; (b) red/green; (c) yellow/blue; (d) Chroma; (e) Whitness index. The green line and green letters are related to Treccine prepared with EVOO. The black line and black letters are related to Treccine prepared with OPO. Values with different letters with the same colour are significantly different *** p < 0.001; ** p < 0.01.

Figure 5

Sensory analysis of Treccine prepared with olive pomace oil and with extra virgin olive oil during one-year shelf life. (a) Appearance; (b) colour; (c) flavour; (d) taste; (e) texture; (f) overall acceptability. The green line and green letters are related to Treccine prepared with EVOO. The black line and black letters are related to Treccine prepared with OPO. Values with different letters with the same colour are significantly different: *** p < 0.001; ** p < 0.01; * p < 0.05.

Figure 5

Sensory analysis of Treccine prepared with olive pomace oil and with extra virgin olive oil during one-year shelf life. (a) Appearance; (b) colour; (c) flavour; (d) taste; (e) texture; (f) overall acceptability. The green line and green letters are related to Treccine prepared with EVOO. The black line and black letters are related to Treccine prepared with OPO. Values with different letters with the same colour are significantly different: *** p < 0.001; ** p < 0.01; * p < 0.05.

Figure 6

(a) Free acidity and (b) peroxide value of olive pomace oil and extra virgin olive oil extracted from Treccine during one-year shelf life. The green line and green letters are related to Treccine prepared with EVOO. The black line and black letters are related to Treccine prepared with OPO. Values with different letters with the same colour are significantly different: *** p < 0.001; ** p < 0.01.

Figure 7

(a) K 232 and (b) K 268 values of olive pomace oil and extra virgin olive oil extracted from Treccine during one-year shelf life. The green line and green letters are related to Treccine prepared with EVOO. The black line and black letters are related to Treccine prepared with OPO. Values with different letters with the same colour are significantly different: *** p < 0.001.

Figure 8

(a) DPPH hydrophilic fraction, (b) ABTS hydrophilic fraction, (c) DPPH lipolytic fraction, of olive pomace oil and extra virgin olive oil extracted from Treccine during one-year shelf life. The green line and green letters are related to Treccine prepared with EVOO. The black line and black letters are related to Treccine prepared with OPO. Values with different letters with the same colour are significantly different: *** p < 0.001.

Figure 9

(a) Lightness L*, (b) green–red a*, (c) blue–yellow b*, (d) Chroma of olive pomace oil and extra virgin olive oil extracted from Treccine during one-year shelf life. The green line and green letters are related to the Treccine prepared with EVOO. The black line and black letters are related to the Treccine prepared with OPO. Values with different letters with the same colour are significantly different: * p < 0.05; ** p < 0.01; *** p < 0.001.