Application of Phenolic Extracts from Selected Plants in Fruit Juice

Figures & data

Table 1 Yield of extraction, content of total phenolics, and UV data of phenolic extracts

Plant material	Yield (%)	Total phenolics (mg gallic acid/ g extract.)	λ (nm)
Moringa oleifera	40	162.50	270^m, 320–330^sh
Mentha spicata	40	158.75	268^m, 328^m
Morus indica	36	130.50	283^m, 320–330^sh
m:maximum; sh:shoulder.

Figure 1 UV spectra of phenolic extracts from selected plant materials.

Figure 2 Solubility of phenolic extracts added to pineapple juice: (A) Concentration dependence of absorption spectra; (B) linear relationship between concentration and absorbance at maximum wavelength. MO: Moringa oleifera, MI: Morus indica, MS: Mentha spicata.

Figure 3 Stability of selected phenolic extracts in pineapple juice during storage (∼4°C, 2 weeks). MI: Morus indica, MO: Moringa oleifera.

Table 2 Titrable acidity (% citric acid equivalents) of pineapple juice variations during storage (∼4°C, 8 weeks)

Sample∗	Initial	2nd week	4th week	6th week	8th week
Control	0.70 ± 0.02^cl	0.71 ± 0.01^cl	0.77 ± 0.01^cl	0.84 ± 0.02^bl	0.92 ± 0.03^al
Standard	0.70 ± 0.00^al	0.70 ± 0.01^al	0.71 ± 0.02^al	0.70 ± 0.02^am	0.73 ± 0.01^am
Treatment	0.70 ± 0.01^al	0.70 ± 0.00^al	0.72 ± 0.02^al	0.74 ± 0.01^am	0.78 ± 0.02^am
Values are mean ± SD. Values bearing different superscripts a, b,… in rows (comparison between storage period) and l, m,… in columns (comparison between samples), differ significantly (p < 0.05).
∗Control: pineapple juice free from additive; standard: pineapple juice treated with sodium benzoate (200 ppm); treatment: pineapple juice treated with phenolic extract of M. indica (0.25%; w/v).

Table 3 Acceptability of pineapple juice variations during storage (∼4°C, 8 weeks)

Sample∗	Initial	2nd week	4th week	6th week	8th week
Control	8.83 ± 0.90^al	8.00 ± 0.75^al	6.50 ± 0.95^bm	5.16 ± 0.47^cn	4.85 ± 0.98^dn
Standard	8.83 ± 0.75^al	8.63 ± 0.85^al	8.85 ± 0.89^al	8.76 ± 0.81^al	8.25 ± 1.05^al
Treatment	7.83 ± 0.98^al	7.72 ± 0.64^al	7.74 ± 0.96^al	7.25 ± 1.05^am	7.05 ± 0.96^am
Values are mean ± SD. Values bearing different superscripts a, b, … in rows (comparison between storage period) and l, m, … in columns (comparison between samples), differ significantly (p < 0.05).
∗Control: pineapple juice free from additive; standard: pineapple juice treated with sodium benzoate (200 ppm); treatment: pineapple juice treated with phenolic extract of M. indica (0.25%; w/v).