The Effect of Yellow Tea Leaves Camellia sinensis on the Quality of Stored Chocolate Confectionery

Abstract

Chocolate and tea leaves are considered the most valuable sources of highly bioactive polyphenols due to their potential anti-cancer properties and beneficial effects on the cardiovascular and nervous systems. The objective of the present study was the development of a sensory profiling modality that is correlated with the taste of the chocolate enriched with yellow tea phytochemicals. The additive concentration was optimized in white chocolate and the designed product was evaluated using the sensory profiling method. It was shown that the yellow tea extract in chocolate had a significant effect on the taste and color of the product. Addition of 2.0% yellow tea powdered extract increased the value of color acceptance and caused an intensification of the aromas, particularly the leafy taste, compared to the control samples. The next step of the study was to determine the influence of tea addition in white, milk and dark chocolate subjected to 6 months of storage. The designed chocolates were tested for their activity as antioxidants (DPPH, ABTS and ORAC assay) and cholinesterase inhibitors (AChE, BChE assay). It was confirmed that the yellow tea addition affected the activity of prepared chocolates with respect to radical scavenging activity and was highest for dark chocolate with yellow tea where the values were as follows: 4373 mg Tx/100 g (DPPH), 386 mg Tx/100 g (ABTS) and 4363 µM Tx/100 g (ORAC). An increase in the anti-radical activity of chocolate with yellow tea was found after 3 months of storage, but the subsequent 3 months of storage resulted in its reduction. AChE values ranged from 0.118 to 0.730 [µM eserine/g dw] and from 0.095 to 0.480 [µM eserine/g dw] for BChE assay. Total capacity to inhibit AChE and BChE differed depending on the type of chocolate and was negatively influenced by the half-year storage. Summarizing tested values for individual samples were higher, with increasing content of cocoa liquor and yellow tea extract in the product. The results of the research show that the use of yellow tea in confectionery is promising and may appoint a new direction in functional foods.

Physicochemical, Antioxidant, Microstructural Properties and Bioaccessibility of Dark Chocolate with Plant Extracts

“…For comparison, DCh enriched with yellow tea extract had a higher MC (1.56 g/100 g) than the control sample (MC = 1.32 g/100 g) [7]. In contrast, the MC (1.78%) insignificantly decreased with increasing cinnamon bark oleoresin microcapsule content (c = 4, 6 and 8%) added to DCh bars (MC = 1.55-1.68%) [24].…”

“…Similarly, the addition of 2% yellow tea powdered extract caused a reduction in the fat phase in DCh (FC = 28.53 and 27.98 g/100 g for control and enriched chocolate samples, respectively) [7].…”

“…For comparison, the addition of various plant extracts such as red raspberry leaves [5], yellow tea [7], Sakura green tea, turmeric powder [6], black carrot [12], dried cranberries, and prunes [2] to DCh samples and chocolate products caused an increase in AC and TPC analyzed by DPPH, ABTS, FRAP, and F-C assays (Table 4). Unexpectedly, the DPPH, ABTS, and TPC results [3] for all chocolate pralines produced with the addition of either longan or lychee were significantly lower than the antioxidant properties of control samples (Table 4).…”

“…The decrease in reducing activity and scavenging activity of the investigated chocolates after simulated digestion may be due to the loss of the bioactive compounds and/or chemical transformations. [7] 4373 mg TE/100 g for DCh + yellow tea extract [7] 0.08 mg TE/g for CCh [12] 0.16-0.40 mg TE/g for CCh + black carrot extract [12] ABTS 1.91 mmol TE/L for DCh [2] 2.04 mmol TE/L for DCh + cranberries [2] 0.060 mmol TE/g for ChP [3] 0.022-0.044 mmol TE/g for ChP + longan [3] 0.028-0.039 mmol TE/g for ChP + lychee [3] 9 mmol/g for DCh [5] 9-11.5 mmol/g for DCh + red raspberry leaves extract [5] 11 mmol TE/100 g for DCh [6] 15.4 mmol TE/100 g for DCh + Sakura green tea leaves [6] 12.2 mmol TE/100 g for DCh + turmeric powder [6] 285 mg TE/100 g for DCh [7] 386 mg TE/100 g for DCh + yellow tea extract [ [6] 20,090 µmol GA/100 g for DCh + Sakura green tea leaves [6] 17,887 µmol GA/100 g for DCh + turmeric powder [6] 1760 mg C/100 g for DCh [7] 2400 mg C/100 g for DCh + yellow tea extract [7] 56.0 mg GA/kg for CCh [12] 85.0-117.7 mg GA/kg for CCh + black carrot extract [12] Physiological extracts DPPH 0.12 mg TE/g for CCh [12] 0. F-C 1800-10,100 µmol GA/100 g for DCh [6] 1850-13,900 µmol GA/100 g for DCh + Sakura green tea leaves [6] 1900-7800 µmol GA/100 g for DCh + turmeric powder [6] 70.8 mg GA/kg for CCh [12] 106.6-287.7 mg GA/kg for CCh + black carrot extract [12] DCh-dark chocolate; ChP-chocolate pralines; CCh-compound chocolate; C-catechin equivalent; TE-Trolox.…”

“…On the other hand, the characteristics and manufacturing of chocolate potentially allow the addition of pro-health ingredients such as dried fruits and other parts of plants. Therefore, in recent years, the effects of dried fruits and plants, such as prunes, papaya, apricots, raisins, cranberries, lychee, longan, nettle, red raspberry leaves, Sakura green tea, turmeric powder, and yellow tea powdered extracts on the antioxidant capacity (AC) of white, milk, semisweet, and dark chocolates determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2 -azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), ferric-reducing antioxidant power (FRAP), and oxygen radical absorbance capacity (ORAC), as well as levels of dominant antioxidants have been investigated [2][3][4][5][6][7]. The incorporation of dried fruit and plant extracts into chocolates influenced their antioxidant and sensory properties and contributed to the dietary intake of polyphenolic antioxidants.…”