Table 9 Regression equations for response factors at different days and storage intervals after spray drying process

Powder Yield

at O day

Y = +  46.10 + 7.96X₁ + 6.01X₂ + 4.04X₃ + 6.02X₄ + 0.0250X₁X₂–0.0450X₁X₃ + 0.0253X₁X₄ + 0.0256X₂X₃ + 0.0251X₂X₄–6.10X₃X₄ + 0.9350X₁² + 2.92X₂² - 0.0525X₃² - 2.02X₄²

ALA

at O day

Y = +  114.63–6.57X₁ + 3.54X₂–6.53X₃–5.98X₄–0.0925X₁X₂–0.2175X₁X₃ + 0.0975X₁X₄–0.04X₂X₃ + 0.2650X₂X₄–0.0650X₃X₄–0.5215X₁² + 0.4060X₂² + 0.4410X₃² + 1.03X₄²

after 3O days at 4 °C

Y = +  113.44–6.52X₁ + 3.62X₂–6.59X₃–5.82X₄–0.2325X₁X₂–0.1275X₁X₃ + 0.1775X₁X₄ + 0.0925X₂X₃ + 0.1250X₂X₄–0.6450X₃X₄–0.6762X₁² + 0.4050X₂² + 0.6250X₃² + 1.10X₄²

after 6O days at 4 °C

Y = +  110.35–6.59X₁ + 3.57X₂–6.62X₃–5.88X₄ + 0.0450X₁X₂–0.1150X₁X₃ + 0.1100X₁X₄ + 0.1250X₂X₃₋ 0.0600X₂X₄–0.4825X₃X₄–0.6251X₁² + 0.5299X₂² + 0.6037X₃² + 1.33X₄²

after 3O days at 25 °C

Y = +  110.42–6.48X₁ + 3.61X₂–6.42X₃–6.03X₄–0.1200X₁X₂–0.0775X₁X₃ + 0.0750X₁X₄–0.0025X₂X₃₋ 0.0425X₂X₄ + 0.0825X₃X₄–0.4374X₁² + 0.3963X₂² + 0.4776X₃² + 1.06X₄²

after 6O days at 25 °C

Y = +  105.27–6.46X₁ + 3.46X₂–6.48X₃–5.96X₄–0.1775X₁X₂ + 0.0002X₁X₃ + 0.1550X₁X₄ + 0.0400X₂X₃₋ 0.0275X₂X₄ + 0.1400X₃X₄–0.2706X₁² + 0.5007X₂² + 0.6182X₃² + 1.21X₄²

EPA

at O day

Y = +  13.10–0.7508X₁ + 0.3867X₂–0.7467X₃–0.6608X₄–0.0050X₁X₂–0.0150X₁X₃ + 0.0025X₁X₄–0.0100X₂X₃ + 0.0200X₂X₄ + 0.0150X₃X₄–0.0367X₁² + 0.0296X₂² - 0.0329X₃² + 0.0858X₄²

after 3O days at 4 °C

Y = +  12.12–0.7725X₁ + 0.3467X₂–0.7908X₃–0.7067X₄–0.0900X₁X₂–0.2600X₁X₃–0.2525X₁X₄–0.0800X₂X₃₋ 0.1150X₂X₄–0.1925X₃X₄–0.1789X₁²–0.1477X₂² - 0.1064X₃² – 0.0777X₄²

after 6O days at 4 °C

Y = +  8.84–0.8750X₁ + 0.7558X₂–0.4567X₃–0.8092X₄ + 0.2175X₁X₂–0.0425X₁X₃ + 0.0900X₁X₄–0.4625X₂X₃₋ 0.0925X₂X₄–0.2350X₃X₄–0.2227X₁²–0.8714X₂² - 0.4777X₃² – 0.0289X₄²

after 3O days at 25 °C

Y = +  9.80–0.8792X₁ + 0.4425X₂–0.8600X₃–0.8983X₄ + 0.1375X₁X₂ + 0.2050X₁X₃–0.4250X₁X₄ + 0.3325X₂X₃₋ 0.0375X₂X₄–0.5825X₃X₄–0.2229X₁²–0.3329X₂² - 0.4017X₃² – 0.1342X₄²

after 6O days at 25 °C

Y = +  4.60–0.8958X₁ + 0.4550X₂–0.8292X₃–0.8583X₄–0.1425X₁X₂ + 0.2800X₁X₃–0.2650X₁X₄ + 0.1775X₂X₃₋ 0.3650X₂X₄–0.3250X₃X₄–0.2782X₁²–0.2845X₂² - 0.1232X₃² + 0.0030X₄²

DHA

at O day

Y = +  17.43–0.9983X₁ + 0.4808X₂–1.03X₃–0.9300X₄–0.0050X₁X₂ + 0.0200X₁X₃–0.0150X₁X + 0.1000X₂X₃₋ 0.0725X₂X₄–0.0175X₃X₄ + 0.0010X₁² + 0.1823X₂² + 0.0172X₃² + 0.1035X₄²

after 3O days at 4 °C

Y = +  16.16–1.07X₁ + 0.4675X₂–1.03X₃–0.1.04X₄ + 0.1175X₁X₂ + 0.0125X₁X₃ + 0.0450X₁X

- 0.0700X₂X₃ + 0.1650X₂X₄–0.0150X₃X₄ + 0.0808X₁² + 0.6771X₂² + 0.0596X₃² + 0.0308X₄²

after 6O days at 4 °C

Y = +  12.06–1.02X₁ + 0.4983X₂–0.9958X₃–0.8708X₄ + 0.0275X₁X₂ + 0.0350X₁X₃ + 0.0625X₁X - 0.1425X₂X₃ + 0.1450X₂X₄–0.0800X₃X₄ + 0.0516X₁² + 0.9716X₂² - 0.0222X₃² + 0.0878X₄²

after 3O days at 25 °C

Y = +  13.48–1.07X₁ + 0.5142X₂–0.8950X₃–0.9258X₄–0.0025X₁X₂–0.0600X₁X₃ + 0.2975X₁X - 0.2275X₂X₃ + 0.1125X₂X₄–0.1375X₃X₄ + 0.0131X₁² + 0.7218X₂² - 0.1794X₃² + 0.0593X₄²

after 6O days at 25 °C

Y = +  8.54–1.00X₁ + 0.3583X₂–0.9850X₃–0.9058X₄–0.0750X₁X₂–0.1450X₁X₃–0.0025X₁X - 0.1750X₂X₃₋ 0.0300X₂X₄–0.0950X₃X₄ + 0.1923X₁² + 0.5889X₂² + 0.0389X₃² + 0.0027X₄²

TOFA

at O day

Y = +  145.32–8.32X₁ + 5.24X₂–8.30X₃–6.77X₄–0.0950X₁X₂ + 0.2125X₁X₃ + 0.0825X₁X + 0.0600X₂X₃ + 2.70X₂X₄–0.0825X₃X₄–1.06X₁² + 1.36X₂² - 0.0837X₃² + 1.96X₄²

after 3O days at 4 °C

Y = +  141.69–8.36X₁ + 4.43X₂–8.42X₃–7.56X₄–0.2050X₁X₂ + 0.3750X₁X₃–0.0300X₁X - 0.0575X₂X₃ + 0.1750X₂X₄–0.8275X₃X₄–0.7562X₁² + 0.9526X₂² + 0.5838X₃² + 1.06X₄²

after 6O days at 4 °C

Y = +  131.50–8.48X₁ + 4.82X₂–8.08X₃–7.57X₄ + 0.3000X₁X₂–0.1225X₁X₃ + 0.2675X₁X - 0.4800X₂X₃₋ 0.0075X₂X₄–0.7975X₃X₄–0.9235X₁² + 0.5053X₂² - 0.0260X₃² + 1.26X₄²

after 3O days at 25 °C

Y = +  134.70–8.43X₁ + 4.53X₂–8.25X₃–7.96X₄–0.0450X₁X₂ + 0.0675X₁X₃ + 0.0001X₁X + 0.0650X₂X₃ + 0.0325X₂X₄–0.1400X₃X₄–1.19X₁² + 0.3461X₂² - 0.4489X₃² + 0.5311X₄²

after 6O days at 25 °C

Y = +  118.80–8.37X₁ + 4.27X₂–8.23X₃–7.79X₄–0.3950X₁X₂–0.4250X₁X₃–0.1125X₁X + 0.0425X₂X₃ - 4225X₂X₄–0.1000X₃X₄–0.9022X₁² + 0.6441X₂² + 0.2828X₃² + 0.9691X₄²

PV

at O day

Y = +  0.5300 + 0.0492X₁ + 0.0192X₂ + 0.0200X₃ + 0.0650X₄ + 0.0001X₁X₂–0.0025X₁X₃ + 0.0001X₁X + 0.0025X₂X₃ + 0.0001X₂X₄ + 0.0001X₃X₄ + 0.0004X₁² + 0.0003X₂² + 0.0017X₃² + 0.0042X₄²

after 3O days at 4 °C

Y = +  0.5900 + 0.0500X₁ + 0.0192X₂ + 0.0183X₃ + 0.0642X₄–0.0025X₁X₂ + 0.0026X₁X₃ + 0.0002X₁X + 0.0027X₂X₃₋ 0.0028X₂X₄ + 0.0003X₃X₄–0.0025X₁² + 0.0013X₂² + 0.0001X₃² + 0.0062X₄²

after 6O days at 4 °C

Y = +  0.6600 + 0.0501X₁ + 0.0175X₂ + 0.0192X₃ + 0.0650X₄–0.0023X₁X₂ + 0.0025X₁X₃ + 0.0001X₁X + 0.0002X₂X₃ + 0.0003X₂X₄ + 0.0001X₃X₄–0.0022X₁² + 0.0012X₂² + 0.0012X₃² + 0.0050X₄²

after 3O days at 25 °C

Y = +  0.6000 + 0.0558X₁ + 0.0100X₂ + 0.0117X₃ + 0.0525X₄ + 0.0025X₁X₂–0.0024X₁X₃–0.0225X₁X - 0.0226X₂X₃₋ 0.0100X₂X₄ + 0.0001X₃X₄ + 0.0146X₁²–0.0117X₂² - 0.0116X₃² + 0.0171X₄²

after 6O days at 25 °C

Y = +  0.6900 + 0.0517X₁ + 0.0083X₂ + 0.0116X₃ + 0.0600X₄ + 0.0024X₁X₂–0.0050X₁X₃–0.0125X₁X - 0.0200X₂X₃₋ 0.0025X₂X₄ + 0.0002X₃X₄ + 0.0113X₁²–0.0087X₂² - 0.0088X₃² + 0.0137X₄²